Sample records for tailless fighter aircraft

  1. X-36 Tailless Fighter Agility Research Aircraft in flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The tailless X-36 technology demonstrator research aircraft cruises over the California desert at low altitude during a 1997 research flight. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine

  2. X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA and McDonnell Douglas Corporation (MDC) personnel remove protective covers from the newly arrived NASA/McDonnell Douglas Corporation X-36 Tailless Fighter Agility Research Aircraft. It arrived at NASA Dryden Flight Research Center, Edwards, California, on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1

  3. X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft in it's hangar at NASA Dryden Flight Research Center, Edwards, California, following its arrival on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of

  4. X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA and McDonnell Douglas Corporation (MDC) personnel wait to attach a hoist to the X-36 Tailless Fighter Agility Research Aircraft, which arrived at NASA Dryden Flight Research Center, Edwards, California, on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high

  5. X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft is steered to it's hangar at NASA Dryden Flight Research Center, Edwards, California, following arrival on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a

  6. X-36 Tailless Fighter Agility Research Aircraft in flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The X-36 technology demonstrator shows off its distinctive shape as the remotely piloted aircraft flies a research mission over the Southern California desert on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams

  7. X-36 Tailless Fighter Agility Research Aircraft in flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The lack of a vertical tail on the X-36 technology demonstrator is evident as the remotely piloted aircraft flies a low-altitude research flight above Rogers Dry Lake at Edwards Air Force Base in the California desert on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three

  8. X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. More taxi and radio frequency tests were slated before it's first flight would be made. This took place on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems

  9. X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X

  10. The X-31A quasi-tailless flight test results

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.; Stoliker, P. C.

    1996-01-01

    A quasi-tailless flight investigation was launched using the X-31A enhanced fighter maneuverability airplane. In-flight simulations were used to assess the effect of partial to total vertical tail removal. The rudder control surface was used to cancel the stabilizing effects of the vertical tail, and yaw thrust vector commands were used to restabilize and control the airplane. The quasi-tailless mode was flown supersonically with gentle maneuvering and subsonically in precision approaches and ground attack profiles. Pilot ratings and a full set of flight test measurements were recorded. This report describes the results obtained and emphasizes the lessons learned from the X-31A flight test experiment. Sensor-related issues and their importance to a quasi-tailless simulation and to ultimately controlling a directionally unstable vehicle are assessed. The X-31A quasi-tailless flight test experiment showed that tailless and reduced tail fighter aircraft are definitely feasible. When the capability is designed into the airplane from the beginning, the benefits have the potential to outweigh the added complexity required.

  11. Study of aerodynamic technology for VSTOL fighter/attack aircraft: Vertical attitude concept

    NASA Technical Reports Server (NTRS)

    Gerhardt, H. A.; Chen, W. S.

    1978-01-01

    The aerodynamic technology for a vertical attitude VSTOL (VATOL) supersonic fighter/attack aircraft was studied. The selected configuration features a tailless clipped delta wing with leading-edge extension (LEX), maneuvering flaps, top-side inlet, twin dry engines and vectoring nozzles. A relaxed static stability is employed in conjunction with the maneuvering flaps to optimize transonic performance and minimize supersonic trim drag. Control for subaerodynamic flight is obtained by gimballing the nozzles in combination with wing tip jets. Emphasis is placed on the development of aerodynamic characteristics and the identification of aerodynamic uncertainties. A wind tunnel test program is proposed to resolve these uncertainties and ascertain the feasibility of the conceptual design. Ship interface, flight control integration, crew station concepts, advanced weapons, avionics, and materials are discussed.

  12. Wind tunnel test of a tailless aircraft with a belly-flap control surface used in combination with wing flaps

    NASA Astrophysics Data System (ADS)

    Dougherty, Daniel A.

    A wind tunnel tat of a tailless aircraft configuration that has been quipped with a belly-flap control surface, was conducted with the goal of improving the trimmed maximum-lift coefficient. Tailless aircraft have aerodynamic and structural efficiencies that are superior to those of a traditionally configured wing/body/tail aircraft. However, tailless aircraft have a low maximum-lift coefficient such that; when sized for equivalent takeoff performance, the tailless aircraft suffers a large reduction in aerodynamic and structural efficiencies. A Belly-Flap control surface used in combination with wing trailing edge flaps was tested in a wind tunnel with the goal of achieving a longitudinally trimmed solution at a higher maximum lift coefficient. It was determined that, though the Belly-Flap increases the trimmed lift of the tailless configuration at low angles of attack, the maximum lift coefficient is slightly reduced in relation to the controls neutral configuration.

  13. MIMO Sliding Mode Control for a Tailless Fighter Aircraft, An Alternative to Reconfigurable Architectures

    NASA Technical Reports Server (NTRS)

    Wells, S. R.; Hess, R. A.

    2002-01-01

    A frequency-domain procedure for the design of sliding mode controllers for multi-input, multi-output (MIMO) systems is presented. The methodology accommodates the effects of parasitic dynamics such as those introduced by unmodeled actuators through the introduction of multiple asymptotic observers and model reference hedging. The design procedure includes a frequency domain approach to specify the sliding manifold, the observer eigenvalues, and the hedge model. The procedure is applied to the development of a flight control system for a linear model of the Innovative Control Effector (ICE) fighter aircraft. The stability and performance robustness of the resulting design is demonstrated through the introduction of significant degradation in the control effector actuators and variation in vehicle dynamics.

  14. Planform, aero-structural, and flight control optimization for tailless morphing aircraft

    NASA Astrophysics Data System (ADS)

    Molinari, Giulio; Arrieta, Andres F.; Ermanni, Paolo

    2015-04-01

    Tailless airplanes with swept wings rely on variations of the spanwise lift distribution to provide controllability in roll, pitch and yaw. Conventionally, this is achieved utilizing multiple control surfaces, such as elevons, on the wing trailing edge. As every flight condition requires different control moments (e.g. to provide pitching moment equilibrium), these surfaces are practically permanently displaced. Due to their nature, causing discontinuities, corners and gaps, they bear aerodynamic penalties, mostly in terms of shape drag. Shape adaptation, by means of chordwise morphing, has the potential of varying the lift of a wing section by deforming its profile in a way that minimizes the resulting drag. Furthermore, as the shape can be varied differently along the wingspan, the lift distribution can be tailored to each specific flight condition. For this reason, tailless aircraft appear as a prime choice to apply morphing techniques, as the attainable benefits are potentially significant. In this work, we present a methodology to determine the optimal planform, profile shape, and morphing structure for a tailless aircraft. The employed morphing concept is based on a distributed compliance structure, actuated by Macro Fiber Composite (MFC) piezoelectric elements. The multidisciplinary optimization is performed considering the static and dynamic aeroelastic behavior of the resulting structure. The goal is the maximization of the aerodynamic efficiency while guaranteeing the controllability of the plane, by means of morphing, in a set of flight conditions.

  15. Light weight escape capsule for fighter aircraft

    NASA Technical Reports Server (NTRS)

    Robert, James A.

    1988-01-01

    Emergency crew escape capabilities have been less than adequate for fighter aircraft since before WW II. From the over-the-side bailout of those days through the current ejection seat with a rocket catapult, escaping from a disabled aircraft has been risky at best. Current efforts are underway toward developing a high-tech, smart ejection seat that will give fighter pilots more room to live in the sky, but an escape capsule is needed to meet current and future fighter envelopes. Escape capsules have a bad reputation due to past examples of high weight, poor performance and great complexity. However, the advantages available demand that a capsule be developed. This capsule concept will minimize the inherent disavantages and incorporate the benefits while integrating all aspects of crew station design. The resulting design is appropriate for a crew station of the year 2010 and includes improved combat acceleration protection, chemical or biological combat capability, improved aircraft to escape system interaction, and the highest level of escape performance achievable. The capsule is compact, which can allow a reduced aircraft size and weighs only 1200 lb. The escape system weight penalty is only 120 lb higher than that for the next ejection seat and the capsule has a corresponding increase in performance.

  16. Study of aerodynamic technology for VSTOL fighter attack aircraft

    NASA Technical Reports Server (NTRS)

    Burhans, W., Jr.; Crafta, V. J., Jr.; Dannenhoffer, N.; Dellamura, F. A.; Krepski, R. E.

    1978-01-01

    Vertical short takeoff aircraft capability, supersonic dash capability, and transonic agility were investigated for the development of Fighter/attack aircraft to be accommodated on ships smaller than present aircraft carriers. Topics covered include: (1) description of viable V/STOL fighter/attack configuration (a high wing, close-coupled canard, twin-engine, control configured aircraft) which meets or exceeds specified levels of vehicle performance; (2) estimates of vehicle aerodynamic characteristics and the methodology utilized to generate them; (3) description of propulsion system characteristics and vehicle mass properties; (4) identification of areas of aerodynamic uncertainty; and (5) a test program to investigate the areas of aerodynamic uncertainty in the conventional flight mode.

  17. Handling qualities related to stall/spin accidents of supersonic fighter aircraft

    NASA Technical Reports Server (NTRS)

    Anderson, S. B.

    1984-01-01

    This paper reviews the handling qualities which influence the high angle of attack (AOA) behavior of supersonic fighter aircraft in order to obtain a clearer understanding of the causes of stall/spin accidents. The results show that, because modern fighters suffer more serious consequences when control is lost, good handling qualities are essential for safe operation at high AOA. Relaxed static stability used on some fighter aircraft can result in control problems at high AOA owing to inertia coupling and the difficulty of a recovery from a deep stall. Indications are that the use of departure/spin resistance and an automatic spin prevention system will greatly improve the safety record for modern supersonic fighters.

  18. An investigation of fighter aircraft agility

    NASA Technical Reports Server (NTRS)

    Valasek, John; Downing, David R.

    1993-01-01

    This report attempts to unify in a single document the results of a series of studies on fighter aircraft agility funded by the NASA Ames Research Center, Dryden Flight Research Facility and conducted at the University of Kansas Flight Research Laboratory during the period January 1989 through December 1993. New metrics proposed by pilots and the research community to assess fighter aircraft agility are collected and analyzed. The report develops a framework for understanding the context into which the various proposed fighter agility metrics fit in terms of application and testing. Since new metrics continue to be proposed, this report does not claim to contain every proposed fighter agility metric. Flight test procedures, test constraints, and related criteria are developed. Instrumentation required to quantify agility via flight test is considered, as is the sensitivity of the candidate metrics to deviations from nominal pilot command inputs, which is studied in detail. Instead of supplying specific, detailed conclusions about the relevance or utility of one candidate metric versus another, the authors have attempted to provide sufficient data and analyses for readers to formulate their own conclusions. Readers are therefore ultimately responsible for judging exactly which metrics are 'best' for their particular needs. Additionally, it is not the intent of the authors to suggest combat tactics or other actual operational uses of the results and data in this report. This has been left up to the user community. Twenty of the candidate agility metrics were selected for evaluation with high fidelity, nonlinear, non real-time flight simulation computer programs of the F-5A Freedom Fighter, F-16A Fighting Falcon, F-18A Hornet, and X-29A. The information and data presented on the 20 candidate metrics which were evaluated will assist interested readers in conducting their own extensive investigations. The report provides a definition and analysis of each metric; details

  19. Advanced simulation noise model for modern fighter aircraft

    NASA Astrophysics Data System (ADS)

    Ikelheimer, Bruce

    2005-09-01

    NoiseMap currently represents the state of the art for military airfield noise analysis. While this model is sufficient for the current fleet of aircraft, it has limits in its capability to model the new generation of fighter aircraft like the JSF and the F-22. These aircraft's high-powered engines produce noise with significant nonlinear content. Combining this with their ability to vector the thrust means they have noise characteristics that are outside of the basic modeling assumptions of the currently available noise models. Wyle Laboratories, Penn State University, and University of Alabama are in the process of developing a new noise propagation model for the Strategic Environmental Research and Development Program. Source characterization will be through complete spheres (or hemispheres if there is not sufficient data) for each aircraft state (including thrust vector angles). Fixed and rotor wing aircraft will be included. Broadband, narrowband, and pure tone propagation will be included. The model will account for complex terrain and weather effects, as well as the effects of nonlinear propagation. It will be a complete model capable of handling a range of noise sources from small subsonic general aviation aircraft to the latest fighter aircraft like the JSF.

  20. X-36 Tailless Fighter Agility Research Aircraft in flight

    NASA Image and Video Library

    1997-10-30

    The lack of a vertical tail on the X-36 technology demonstrator is evident as the remotely piloted aircraft flies a low-altitude research flight above Rogers Dry Lake at Edwards Air Force Base in the California desert on October 30, 1997.

  1. A technique for the assessment of fighter aircraft precision controllability

    NASA Technical Reports Server (NTRS)

    Sisk, T. R.

    1978-01-01

    Today's emerging fighter aircraft are maneuvering as well at normal accelerations of 7 to 8 g's as their predecessors did at 4 to 5 g's. This improved maneuvering capability has significantly expanded their operating envelope and made the task of evaluating handling qualities more difficult. This paper describes a technique for assessing the precision controllability of highly maneuverable aircraft, a technique that was developed to evaluate the effects of buffet intensity on gunsight tracking capability and found to be a useful tool for the general assessment of fighter aircraft handling qualities. It has also demonstrated its usefulness for evaluating configuration and advanced flight control system refinements. This technique is believed to have application to future aircraft dynamics and pilot-vehicle interface studies.

  2. Preliminary design of a supersonic Short Takeoff and Vertical Landing (STOVL) fighter aircraft

    NASA Technical Reports Server (NTRS)

    Cox, Brian; Borchers, Paul; Gomer, Charlie; Henderson, Dean; Jacobs, Tavis; Lawson, Todd; Peterson, Eric; Ross, Tweed, III; Bellmard, Larry

    1990-01-01

    The preliminary design study of a supersonic Short Takeoff and Vertical Landing (STOVL) fighter is presented. A brief historical survey of powered lift vehicles was presented, followed by a technology assessment of the latest supersonic STOVL engine cycles under consideration by industry and government in the U.S. and UK. A survey of operational fighter/attack aircraft and the modern battlefield scenario were completed to develop, respectively, the performance requirements and mission profiles for the study. Three configurations were initially investigated with the following engine cycles: a hybrid fan vectored thrust cycle, a lift+lift/cruise cycle, and a mixed flow vectored thrust cycle. The lift+lift/cruise aircraft configuration was selected for detailed design work which consisted of: (1) a material selection and structural layout, including engine removal considerations, (2) an aircraft systems layout, (3) a weapons integration model showing the internal weapons bay mechanism, (4) inlet and nozzle integration, (5) an aircraft suckdown prediction, (6) an aircraft stability and control analysis, including a takeoff, hover, and transition control analysis, (7) a performance and mission capability study, and (8) a life cycle cost analysis. A supersonic fighter aircraft with STOVL capability with the lift+lift/cruise engine cycle seems a viable option for the next generation fighter.

  3. X-31 quasi-tailless flight demonstration

    NASA Technical Reports Server (NTRS)

    Huber, Peter; Schellenger, Harvey G.

    1994-01-01

    The primary objective of the quasi-tailless flight demonstration is to demonstrate the feasibility of using thrust vectoring for directional control of an unstable aircraft. By using this low-cost, low-risk approach it is possible to get information about required thrust vector control power and deflection rates from an inflight experiment as well as insight in low-power thrust vectoring issues. The quasi-tailless flight demonstration series with the X-31 began in March 1994. The demonstration flight condition was Mach 1.2 at 37,500 feet. A series of basic flying quality maneuvers, doublets, bank to bank rolls, and wind-up-turns have been performed with a simulated 100% vertical tail reduction. Flight test and supporting simulation demonstrated that the quasi-tailless approach is effective in representing the reduced stability of tailless configurations. The flights also demonstrated that thrust vectoring could be effectively used to stabilize a directionally unstable configuration and provide control power for maneuver coordination.

  4. Practical application of AMLCDs for tactical fighter aircraft

    NASA Astrophysics Data System (ADS)

    McClaskey, Paul; Craddock, Roger

    1995-06-01

    Development and testing of an AMLCD-display to replace a dichroic display in a fighter aircraft environment has presented a unique set of technical challenges. This paper addresses design concepts used on the Engine Fuel Display and proposes design guidelines generally applicable for AMLCD projects.

  5. Control-system techniques for improved departure/spin resistance for fighter aircraft

    NASA Technical Reports Server (NTRS)

    Nguyen, L. T.; Gilbert, W. P.; Ogburn, M. E.

    1980-01-01

    Some fundamental information on control system effects on controllability of highly maneuverable aircraft at high angles of attack are summarized as well as techniques for enhancing fighter aircraft departure/spin resistance using control system design. The discussion includes: (1) a brief review of pertinent high angle of attack phenomena including aerodynamics, inertia coupling, and kinematic coupling; (2) effects of conventional stability augmentation systems at high angles of attack; (3) high angle of attack control system concepts designed to enhance departure/spin resistance; and (4) the outlook for applications of these concepts to future fighters, particularly those designs which incorporate relaxed static stability.

  6. Learning and forgetting in the jet fighter aircraft industry.

    PubMed

    Bongers, Anelí

    2017-01-01

    A recent strategy carried out by the aircraft industry to reduce the total cost of the new generation fighters has consisted in the development of a single airframe with different technical and operational specifications. This strategy has been designed to reduce costs in the Research, Design and Development phase with the ultimate objective of reducing the final unit price per aircraft. This is the case of the F-35 Lightning II, where three versions, with significant differences among them, are produced simultaneously based on a single airframe. Whereas this strategy seems to be useful to cut down pre-production sunk costs, their effects on production costs remain to be studied. This paper shows that this strategy can imply larger costs in the production phase by reducing learning acquisition and hence, the total effect on the final unit price of the aircraft is indeterminate. Learning curves are estimated based on the flyaway cost for the latest three fighter aircraft models: The A/F-18E/F Super Hornet, the F-22A Raptor, and the F-35A Lightning II. We find that learning rates for the F-35A are significantly lower (an estimated learning rate of around 9%) than for the other two models (around 14%).

  7. Learning and forgetting in the jet fighter aircraft industry

    PubMed Central

    2017-01-01

    A recent strategy carried out by the aircraft industry to reduce the total cost of the new generation fighters has consisted in the development of a single airframe with different technical and operational specifications. This strategy has been designed to reduce costs in the Research, Design and Development phase with the ultimate objective of reducing the final unit price per aircraft. This is the case of the F-35 Lightning II, where three versions, with significant differences among them, are produced simultaneously based on a single airframe. Whereas this strategy seems to be useful to cut down pre-production sunk costs, their effects on production costs remain to be studied. This paper shows that this strategy can imply larger costs in the production phase by reducing learning acquisition and hence, the total effect on the final unit price of the aircraft is indeterminate. Learning curves are estimated based on the flyaway cost for the latest three fighter aircraft models: The A/F-18E/F Super Hornet, the F-22A Raptor, and the F-35A Lightning II. We find that learning rates for the F-35A are significantly lower (an estimated learning rate of around 9%) than for the other two models (around 14%). PMID:28957359

  8. Price vs. Performance: The Value of Next Generation Fighter Aircraft

    DTIC Science & Technology

    2007-03-01

    forms. Both the semi-log and log-log forms were plagued with heteroskedasticity (according to the Breusch - Pagan /Cook-Weisberg test ). The RDT&E models...from 1949-present were used to construct two models – one based on procurement costs and one based on research, design, test , and evaluation (RDT&E...fighter aircraft hedonic models include several different categories of variables. Aircraft procurement costs and research, design, test , and

  9. External store effects on the stability of fighter and interceptor airplanes. [application to military aircraft mission requirements

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.; Sawyer, W. C.

    1974-01-01

    Some criteria for external carriage of missiles for fighter aircraft intended for aerial combat missions and for fighter-interceptor missions are considered. The mission requirements discussed include the short-range fighter-interceptor, the short-range interceptor, the medium-range interceptor, and the long-range interceptor. Missiles types considered to be compatible with the various point mission designs include the short-range missile, the medium-range missile, and the long-range missile. From the study, it appears that point mission design aircraft can be arranged in such a way that the required external-store arrangement will not impair the stability of the aircraft. An extensive reference list of NASA external store research is included.

  10. Geometry definition and grid generation for a complete fighter aircraft

    NASA Technical Reports Server (NTRS)

    Edwards, T. A.

    1986-01-01

    Recent advances in computing power and numerical solution procedures have enabled computational fluid dynamicists to attempt increasingly difficult problems. In particular, efforts are focusing on computations of complex three-dimensional flow fields about realistic aerodynamic bodies. To perform such computations, a very accurate and detailed description of the surface geometry must be provided, and a three-dimensional grid must be generated in the space around the body. The geometry must be supplied in a format compatible with the grid generation requirements, and must be verified to be free of inconsistencies. This paper presents a procedure for performing the geometry definition of a fighter aircraft that makes use of a commercial computer-aided design/computer-aided manufacturing system. Furthermore, visual representations of the geometry are generated using a computer graphics system for verification of the body definition. Finally, the three-dimensional grids for fighter-like aircraft are generated by means of an efficient new parabolic grid generation method. This method exhibits good control of grid quality.

  11. Geometry definition and grid generation for a complete fighter aircraft

    NASA Technical Reports Server (NTRS)

    Edwards, Thomas A.

    1986-01-01

    Recent advances in computing power and numerical solution procedures have enabled computational fluid dynamicists to attempt increasingly difficult problems. In particular, efforts are focusing on computations of complex three-dimensional flow fields about realistic aerodynamic bodies. To perform such computations, a very accurate and detailed description of the surface geometry must be provided, and a three-dimensional grid must be generated in the space around the body. The geometry must be supplied in a format compatible with the grid generation requirements, and must be verified to be free of inconsistencies. A procedure for performing the geometry definition of a fighter aircraft that makes use of a commercial computer-aided design/computer-aided manufacturing system is presented. Furthermore, visual representations of the geometry are generated using a computer graphics system for verification of the body definition. Finally, the three-dimensional grids for fighter-like aircraft are generated by means of an efficient new parabolic grid generation method. This method exhibits good control of grid quality.

  12. Pilot Human Factors in Stall/Spin Accidents of Supersonic Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    Anderson, S. B.; Enevoldson, E. K.; Nguyen, L. T.

    1983-01-01

    A study has been made of pilot human factors related to stall/spin accidents of supersonic fighter aircraft. The military specifications for flight at high angles of attack are examined. Several pilot human factors problems related to stall/spin are discussed. These problems include (1) unsatisfactory nonvisual warning cues; (2) the inability of the pilot to quickly determine if the aircraft is spinning out of control, or to recognize the type of spin; (3) the inability of the pilot to decide on and implement the correct spin recovery technique; (4) the inability of the pilot to move, caused by high angular rotation; and (5) the tendency of pilots to wait too long in deciding to abandon the irrecoverable aircraft. Psycho-physiological phenomena influencing pilot's behavior in stall/spin situations include (1) channelization of sensory inputs, (2) limitations in precisely controlling several muscular inputs, (3) inaccurate judgment of elapsed time, and (4) disorientation of vestibulo-ocular inputs. Results are given of pilot responses to all these problems in the F14A, F16/AB, and F/A-18A aircraft. The use of departure spin resistance and automatic spin prevention systems incorporated on recent supersonic fighters are discussed. These systems should help to improve the stall/spin accident record with some compromise in maneuverability.

  13. Preliminary design of a supersonic Short-Takeoff and Vertical-Landing (STOVL) fighter aircraft

    NASA Technical Reports Server (NTRS)

    1990-01-01

    A preliminary study of a supersonic short takeoff and vertical landing (STOVL) fighter is presented. Three configurations (a lift plus lift/cruise concept, a hybrid fan vectored thrust concept, and a mixed flow vectored thrust concept) were initially investigated with one configuration selected for further design analysis. The selected configuration, the lift plus lift/cruise concept, was successfully integrated to accommodate the powered lift short takeoff and vertical landing requirements as well as the demanding supersonic cruise and point performance requirements. A supersonic fighter aircraft with a short takeoff and vertical landing capability using the lift plus lift/cruise engine concept seems a viable option for the next generation fighter.

  14. F-35 Joint Strike Fighter Aircraft (F-35)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report ( SAR ) RCS: DD-A&T(Q&A)823-198 F-35 Joint Strike Fighter Aircraft (F-35) As of FY 2017 President’s Budget Defense...Acquisition Management Information Retrieval (DAMIR) March 21, 2016 08:47:09 UNCLASSIFIED F-35 December 2015 SAR March 21, 2016 08:47:09 UNCLASSIFIED 2...Document OSD - Office of the Secretary of Defense O&S - Operating and Support PAUC - Program Acquisition Unit Cost F-35 December 2015 SAR March 21

  15. Top-mounted inlet system feasibility for transonic-supersonic fighter aircraft. [V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Williams, T. L.; Hunt, B. L.; Smeltzer, D. B.; Nelms, W. P.

    1981-01-01

    The more salient findings are presented of recent top inlet performance evaluations aimed at assessing the feasibility of top-mounted inlet systems for transonic-supersonic fighter aircraft applications. Top inlet flow field and engine-inlet performance test data show the influence of key aircraft configuration variables-inlet longitudinal position, wing leading-edge extension planform area, canopy-dorsal integration, and variable incidence canards-on top inlet performance over the Mach range of 0.6 to 2.0. Top inlet performance data are compared with those or more conventional inlet/airframe integrations in an effort to assess the viability of top-mounted inlet systems relative to conventional inlet installations.

  16. Accurate Modeling of Stability and Control Properties for Fighter Aircraft from CFD

    DTIC Science & Technology

    2012-03-01

    first an aircraft to flight test which is not until late in the design phase where millions if not billions of dollars have already been invested. It...of an aircraft and even late in the design phase there are often large gaps in data due to budget cuts to flight testing and limitations to maneuvers...early in the design cycle has been the source of many costly fixes to fighter aircraft after flight testing begins. Early prediction of these nonlinear

  17. X-36 on Ramp Viewed from Above

    NASA Image and Video Library

    1997-07-16

    This look-down view of the X-36 Tailless Fighter Agility Research Aircraft on the ramp at NASA’s Dryden Flight Research Center, Edwards, California, clearly shows the unusual wing and canard design of the remotely-piloted aircraft.

  18. An analytical approach to air defense: cost, effectiveness and SWOT analysis of employing fighter aircraft and modern SAM systems

    NASA Astrophysics Data System (ADS)

    Kus, Orcun; Kocaman, Ibrahim; Topcu, Yucel; Karaca, Volkan

    2012-05-01

    The problem of defending a specific airspace is among the main issues a military commander to solve. Proper protection of own airspace is crucial for mission success at the battlefield. The military doctrines of most world armed forces involve two main options of defending the airspace. One of them is utilizing formations of fighter aircraft, which is a flexible choice. The second option is deploying modern SAM (Surface to Air Missile) systems, which is more expansive. On the other hand the decision makers are to cope with miscellaneous restrictions such as the budgeting problems. This study defines air defense concept according to modern air warfare doctrine. It considers an air defense scenario over an arbitrary airspace and compares the performance and cost-effectiveness of employing fighter aircraft and SAM systems. It also presents SWOT (Strenghts - Weakness - Opportunities - Threats) analyses of air defense by fighter aircraft and by modern SAMs and tries to point out whichever option is better. We conclude that deploying SAMs has important advantages over using fighter aircraft by means of interception capacity within a given time period and is cost-effective.

  19. Euler Technology Assessment for Preliminary Aircraft Design-Unstructured/Structured Grid NASTD Application for Aerodynamic Analysis of an Advanced Fighter/Tailless Configuration

    NASA Technical Reports Server (NTRS)

    Michal, Todd R.

    1998-01-01

    This study supports the NASA Langley sponsored project aimed at determining the viability of using Euler technology for preliminary design use. The primary objective of this study was to assess the accuracy and efficiency of the Boeing, St. Louis unstructured grid flow field analysis system, consisting of the MACGS grid generation and NASTD flow solver codes. Euler solutions about the Aero Configuration/Weapons Fighter Technology (ACWFT) 1204 aircraft configuration were generated. Several variations of the geometry were investigated including a standard wing, cambered wing, deflected elevon, and deflected body flap. A wide range of flow conditions, most of which were in the non-linear regimes of the flight envelope, including variations in speed (subsonic, transonic, supersonic), angles of attack, and sideslip were investigated. Several flowfield non-linearities were present in these solutions including shock waves, vortical flows and the resulting interactions. The accuracy of this method was evaluated by comparing solutions with test data and Navier-Stokes solutions. The ability to accurately predict lateral-directional characteristics and control effectiveness was investigated by computing solutions with sideslip, and with deflected control surfaces. Problem set up times and computational resource requirements were documented and used to evaluate the efficiency of this approach for use in the fast paced preliminary design environment.

  20. X-36 in Flight over Mojave Desert during 5th Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The unusual lines of the X-36 Tailless Fighter Agility Research Aircraft contrast sharply with the desert floor as the remotely-piloted aircraft flies over the Mojave Desert on a June 1997 research flight. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of

  1. X-36 in Flight near Edge of Rogers Dry Lake during 5th Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This photo shows the X-36 Tailless Fighter Agility Research Aircraft passing over the edge of Rogers Dry Lake as the remotely-piloted aircraft flies over Edwards Air Force Base on a June 1997 research flight. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of

  2. X-36 on Ramp Viewed from Above

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This look-down view of the X-36 Tailless Fighter Agility Research Aircraft on the ramp at NASA's Dryden Flight Research Center, Edwards, California, clearly shows the unusual wing and canard design of the remotely-piloted aircraft. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet

  3. X-36 arrival at Dryden

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA and McDonnell Douglas Corporation (MDC) personnel steady the X-36 Tailless Fighter Agility Research Aircraft following arrival at NASA Dryden Flight Research Center, Edwards, California, on July 2, 1996. The aircraft is being hoisted out of it's shipping crate. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds

  4. Assessment of aerodynamic performance of V/STOL and STOVL fighter aircraft

    NASA Technical Reports Server (NTRS)

    Nelms, W. P.

    1984-01-01

    The aerodynamic performance of V/STOL and STOVL fighter/attack aircraft was assessed. Aerodynamic and propulsion/airframe integration activities are described and small and large scale research programs are considered. Uncertainties affecting aerodynamic performance that are associated with special configuration features resulting from the V/STOL requirement are addressed. Example uncertainties relate to minimum drag, wave drag, high angle of attack characteristics, and power induced effects.

  5. X-36 Being Prepared on Lakebed for First Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, technicians prepare the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight in May 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet

  6. X-36 Being Prepared on Lakebed for First Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, a technician prepares the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19

  7. X-36 Taking off during First Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The remotely-piloted X-36 Tailless Fighter Agility Research Aircraft lifts off from Rogers Dry Lake at the Dryden Flight Research Center on its first flight on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams

  8. X-36 Being Prepared on Lakebed for First Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, technicians prepares the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19

  9. X-36 Being Prepared on Lakebed for First Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    As the sun creeps above the horizon of Rogers Dry Lake at NASA's Dryden Flight Research Center, Edwards, California, technicians make final preparations for the first flight of the X-36 Tailless Fighter Agility Research Aircraft. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet

  10. A Pilot Opinion Study of Lateral Control Requirements for Fighter-Type Aircraft

    NASA Technical Reports Server (NTRS)

    Creer, Brent Y.; Stewart, John D.; Merrick, Robert B.; Drinkwater, Fred J., III

    1959-01-01

    As part of a continuing NASA program of research on airplane handling qualities, a pilot opinion investigation has been made on the lateral control requirements of fighter aircraft flying in their combat speed range. The investigation was carried out using a stationary flight simulator and a moving flight simulator, and the flight simulator results were supplemented by research tests in actual flight. The flight simulator study was based on the presumption that the pilot rates the roll control of an airplane primarily on a single-degree-of-freedom basis; that is, control of angle of roll about the aircraft body axis being of first importance. From the assumption of a single degree of freedom system it follows that there are two fundamental parameters which govern the airplane roll response, namely the roll damping expressed as a time constant and roll control power in terms of roll acceleration. The simulator study resulted in a criterion in terms of these two parameters which defines satisfactory, unsatisfactory, and unacceptable roll performance from a pilot opinion standpoint. The moving simulator results were substantiated by the in-flight investigation. The derived criterion was compared with the roll performance criterion based upon wing tip helix angle and also with other roll performance concepts which currently influence the roll performance design of military fighter aircraft flying in their combat speed range.

  11. Recent research related to prediction of stall/spin characteristics of fighter aircraft

    NASA Technical Reports Server (NTRS)

    Nguyen, L. T.; Anglin, E. L.; Gilbert, W. P.

    1976-01-01

    The NASA Langley Research Center is currently engaged in a stall/spin research program to provide the fundamental information and design guidelines required to predict the stall/spin characteristics of fighter aircraft. The prediction methods under study include theoretical spin prediction techniques and piloted simulation studies. The paper discusses the overall status of theoretical techniques including: (1) input data requirements, (2) math model requirements, and (3) correlation between theoretical and experimental results. The Langley Differential Maneuvering Simulator (DMS) facility has been used to evaluate the spin susceptibility of several current fighters during typical air combat maneuvers and to develop and evaluate the effectiveness of automatic departure/spin prevention concepts. The evaluation procedure is described and some of the more significant results of the studies are presented.

  12. X-36 Being Prepared on Lakebed for First Flight

    NASA Image and Video Library

    1997-05-17

    As the sun creeps above the horizon of Rogers Dry Lake at NASA's Dryden Flight Research Center, Edwards, California, technicians make final preparations for the first flight of the X-36 Tailless Fighter Agility Research Aircraft.

  13. Study of aerodynamic technology for single-cruise-engine V/STOL fighter/attack aircraft

    NASA Technical Reports Server (NTRS)

    Mark, L.

    1982-01-01

    Conceptual designs and analyses were conducted on two V/STOL supersonic fighter/attack aircraft. These aircraft feature low footprint temperature and pressure thrust augmenting ejectors in the wings for vertical lift, combined with a low wing loading, low wave drag airframe for outstanding cruise and supersonic performance. Aerodynamic, propulsion, performance, and mass properties were determined and are presented for each aircraft. Aerodynamic and Aero/Propulsion characteristics having the most significant effect on the success of the up and away flight mode were identified, and the certainty with which they could be predicted was defined. A wind tunnel model and test program are recommended to resolve the identified uncertainties.

  14. Study of aerodynamic technology for single-cruise-engine VSTOL fighter/attack aircraft, phase 1

    NASA Technical Reports Server (NTRS)

    Foley, W. H.; Sheridan, A. E.; Smith, C. W.

    1982-01-01

    A conceptual design and analysis on a single engine VSTOL fighter/attack aircraft is completed. The aircraft combines a NASA/deHavilland ejector with vectored thrust and is capable of accomplishing the mission and point performance of type Specification 169, and a flight demonstrator could be built with an existing F101/DFE engine. The aerodynamic, aero/propulsive, and propulsive uncertainties are identified, and a wind tunnel program is proposed to address those uncertainties associated with wing borne flight.

  15. Design of a fifth generation air superiority fighter

    NASA Astrophysics Data System (ADS)

    Atique, Md. Saifuddin Ahmed; Barman, Shuvrodeb; Nafi, Asif Shahriar; Bellah, Masum; Salam, Md. Abdus

    2016-07-01

    Air Superiority Fighter is considered to be an effective dogfighter which is stealthy & highly maneuverable to surprise enemy along with improve survivability against the missile fire. This new generation fighter aircraft requires fantastic aerodynamics design, low wing loading (W/S), high thrust to weight ratio (T/W) with super cruise ability. Conceptual design is the first step to design an aircraft. In this paper conceptual design of an Air Superiority Fighter Aircraft is proposed to carry 1 crew member (pilot) that can fly at maximum Mach No of 2.3 covering a range of 1500 km with maximum ceiling of 61,000 ft. Payload capacity of this proposed aircraft is 6000 lb that covers two advanced missiles & one advanced gun. The Air Superiority Fighter Aircraft was designed to undertake all the following missions like: combat air petrol, air to air combat, maritime attack, close air support, suppression, destruction of enemy air defense and reconnaissance.

  16. Results of recent NASA studies on automatic spin prevention for fighter aircraft

    NASA Technical Reports Server (NTRS)

    Chambers, J. R.; Nguyen, L. T.

    1976-01-01

    A broad based research program was developed to eliminate or minimize inadvertent spins for advanced military aircraft. Recent piloted simulator studies and airplane flight tests have demonstrated that the automatic control systems in use on current fighters can be tailored to provide a high degree of spin resistance for some configurations without restrictions to maneuverability. Such systems result in greatly increased tactical effectiveness, safety, and pilot confidence.

  17. X-36 on Ground after Radio and Telemetry Tests

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A UH-1 helicopter lowers the X-36 Tailless Fighter Agility Research Aircraft to the ground after radio frequency and telemetry tests above Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, in November 1996. The purpose of taking the X-36 aloft for the radio and telemetry system checkouts was to test the systems more realistically while airborne. More taxi and radio frequency tests were conducted before the aircraft's first flight in early 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and

  18. X-36 Carried Aloft by Helicopter during Radio and Telemetry Tests

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A Bell UH-1 helicopter lifts the X-36 Tailless Fighter Agility Research Aircraft off the ground for radio frequency and telemetry tests above Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, in November 1996. The purpose of taking the X-36 aloft for the radio and telemetry system checkouts was to test the systems more realistically while airborne. More taxi and radio frequency tests were conducted before the aircraft's first flight in early 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed/ high angles of attack and at high speed/low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and

  19. X-36 during First Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The remotely-piloted X-36 Tailless Fighter Agility Research Aircraft climbs out from Rogers Dry Lake at the Dryden Flight Research Center on its first flight in May 1997. The aircraft flew for five minutes and reached an altitude of approximately 4,900 feet. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19

  20. X-36 Carried Aloft by Helicopter during Radio and Telemetry Tests

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A Bell UH-1 helicopter lifts the X-36 Tailless Fighter Agility Research Aircraft off the ground for radio frequency and telemetry tests above Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, in November 1996. The purpose of taking the X-36 aloft for the radio and telemetry system checkouts was to test the systems more realistically while airborne. More taxi and radio frequency tests were conducted before the aircraft's first flight in early 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and

  1. X-36 Being Prepared on Lakebed for First Flight

    NASA Image and Video Library

    1997-05-17

    Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, technicians prepare the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight in May 1997.

  2. X-36 Being Prepared on Lakebed for First Flight

    NASA Image and Video Library

    1997-05-17

    Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, technicians prepares the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight on May 17, 1997.

  3. Design criteria for integrated flight/propulsion control systems for STOVL fighter aircraft

    NASA Technical Reports Server (NTRS)

    Franklin, James A.

    1993-01-01

    As part of NASA's program to develop technology for short takeoff and vertical landing (STOVL) fighter aircraft, control system designs have been developed for a conceptual STOVL aircraft. This aircraft is representative of the class of mixed-flow remote-lift concepts that was identified as the preferred design approach by the US/UK STOVL Joint Assessment and Ranking Team. The control system designs have been evaluated throughout the powered-lift flight envelope on Ames Research Center's Vertical Motion Simulator. Items assessed in the control system evaluation were: maximum control power used in transition and vertical flight, control system dynamic response associated with thrust transfer for attitude control, thrust margin in the presence of ground effect and hot gas ingestion, and dynamic thrust response for the engine core. Effects of wind, turbulence, and ship airwake disturbances are incorporated in the evaluation. Results provide the basis for a reassessment of existing flying qualities design criteria applied to STOVL aircraft.

  4. 78 FR 34656 - Record of Decision for the F-15 Aircraft Conversion, 144th Fighter Wing, California Air National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ... DEPARTMENT OF DEFENSE Department of the Air Force Record of Decision for the F-15 Aircraft Conversion, 144th Fighter Wing, California Air National Guard, Fresno-Yosemite International Airport Final... May 31, 2013, the United States Air Force signed the ROD for the F-15 Aircraft Conversion for the...

  5. X-36 Being Prepared on Lakebed for First Flight

    NASA Image and Video Library

    1997-05-17

    Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, a technician prepares the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight on May 17, 1997.

  6. Hardware-in-the-loop environment facility to address pilot-vehicle-interface issues of a fighter aircraft

    NASA Astrophysics Data System (ADS)

    Pandurangareddy, Meenige

    2002-07-01

    The evolution of Pilot-Vehicle-Interface (PVI) of a fighter aircraft is a complex task. The PVI design involves both static and dynamic issues. Static issues involve the study of reach of controls and switches, ejection path clearance, readability of indicators and display symbols, etc. Dynamic issues involve the study of the effect of aircraft motion on display symbols, pilot emergency handling, situation awareness, weapon aiming, etc. This paper describes a method of addressing the above issues by building a facility with cockpit, which is ergonomically similar to the fighter cockpit. The cockpit is also fitted with actual displays, controls and switches. The cockpit is interfaced with various simulation models of aircraft and outside-window-image generators. The architecture of the facility is designed to represent the latencies of the aircraft and facilitates replacement of simulation models with actual units. A parameter injection facility could be used to induce faults in a comprehensive manner. Pilots could use the facility right from familiarising themselves with procedures to start the engine, take-off, navigate, aim the weapons, handling of emergencies and landing. This approach is being followed and further being enhanced on Cockpit-Environment-Facility (CEF) at Aeronautical Development Agency (ADA), Bangalore, India.

  7. Easy method of matching fighter engine to airframe for use in aircraft engine design courses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mattingly, J.D.

    1989-01-01

    The proper match of the engine(s) to the airframe affects both aircraft size and life cycle cost. A fast and straightforward method is developed and used for the matching of fighter engine(s) to airframes during conceptual design. A thrust-lapse equation is developed for the dual-spool, mixed-flow, afterburning turbofan type of engine based on the installation losses of 'Aircraft Engine Design' and the performance predictions of the cycle analysis programs ONX and OFFX. Using system performance requirements, the effects of aircraft thrust-to-weight, wing loading, and engine cycle on takeoff weight are analyzed and example design course results presented. 5 refs.

  8. Criteria for design of integrated flight/propulsion control systems for STOVL fighter aircraft

    NASA Technical Reports Server (NTRS)

    Franklin, James A.

    1993-01-01

    As part of NASA's program to develop technology for short takeoff and vertical landing (STOVL) fighter aircraft, control system designs have been developed for a conceptual STOVL aircraft. This aircraft is representative of the class of mixed-flow remote-lift concepts that was identified as the preferred design approach by the U.S./U.K. STOVL Joint Assessment and Ranking Team. The control system designs have been evaluated throughout the powered-lift flight envelope on the Vertical Motion Simulator (VMS) at Ames Research Center. Items assessed in the control system evaluation were: maximum control power used in transition and vertical flight, control system dynamic response associated with thrust transfer for attitude control, thrust margin in the presence of ground effect and hot-gas ingestion, and dynamic thrust response for the engine core. Effects of wind, turbulence, and ship airwake disturbances are incorporated in the evaluation. Results provide the basis for a reassessment of existing flying-qualities design criteria applied to STOVL aircraft.

  9. Study of aerodynamic technology for single-cruise-engine V/STOL fighter/attack aircraft

    NASA Technical Reports Server (NTRS)

    Hess, J. R.; Bear, R. L.

    1982-01-01

    A viable, single engine, supersonic V/STOL fighter/attack aircraft concept was defined. This vectored thrust, canard wing configuration utilizes an advanced technology separated flow engine with fan stream burning. The aerodynamic characteristics of this configuration were estimated and performance evaluated. Significant aerodynamic and aerodynamic propulsion interaction uncertainties requiring additional investigation were identified. A wind tunnel model concept and test program to resolve these uncertainties and validate the aerodynamic prediction methods were defined.

  10. Study of aerodynamic technology for VSTOL fighter/attack aircraft: Horizontal attitude concept

    NASA Technical Reports Server (NTRS)

    Brown, S. H.

    1978-01-01

    A horizontal attitude VSTOL (HAVSTOL) supersonic fighter attack aircraft powered by RALS turbofan propulsion system is analyzed. Reaction control for subaerodynamic flight is obtained in pitch and yaw from the RALS and roll from wingtip jets powered by bleed air from the RALS duct. Emphasis is placed on the development of aerodynamic characteristics and the identification of aerodynamic uncertainties. A wind tunnel program is shown to resolve some of the uncertainties. Aerodynamic data developed are static characteristics about all axes, control effectiveness, drag, propulsion induced effects and reaction control characteristics.

  11. Flight demonstration of a self repairing flight control system in a NASA F-15 fighter aircraft

    NASA Technical Reports Server (NTRS)

    Urnes, James M.; Stewart, James; Eslinger, Robert

    1990-01-01

    Battle damage causing loss of control capability can compromise mission objectives and even result in aircraft loss. The Self Repairing Flight Control System (SRFCS) flight development program directly addresses this issue with a flight control system design that measures the damage and immediately refines the control system commands to preserve mission potential. The system diagnostics process detects in flight the type of faults that are difficult to isolate post flight, and thus cause excessive ground maintenance time and cost. The control systems of fighter aircraft have the control power and surface displacement to maneuver the aircraft in a very large flight envelope with a wide variation in airspeed and g maneuvering conditions, with surplus force capacity available from each control surface. Digital flight control processors are designed to include built-in status of the control system components, as well as sensor information on aircraft control maneuver commands and response. In the event of failure or loss of a control surface, the SRFCS utilizes this capability to reconfigure control commands to the remaining control surfaces, thus preserving maneuvering response. Correct post-flight repair is the key to low maintainability support costs and high aircraft mission readiness. The SRFCS utilizes the large data base available with digital flight control systems to diagnose faults. Built-in-test data and sensor data are used as inputs to an Onboard Expert System process to accurately identify failed components for post-flight maintenance action. This diagnostic technique has the advantage of functioning during flight, and so is especially useful in identifying intermittent faults that are present only during maneuver g loads or high hydraulic flow requirements. A flight system was developed to test the reconfiguration and onboard maintenance diagnostics concepts on a NASA F-15 fighter aircraft.

  12. Forebody/Inlet of the Joint Strike Fighter Tested at Low Speeds

    NASA Technical Reports Server (NTRS)

    Johns, Albert L.

    1998-01-01

    As part of a national cooperative effort to develop a multinational fighter aircraft, a model of a Joint Strike Fighter concept was tested in several NASA Lewis Research Center wind tunnels at low speeds over a range of headwind velocities and model attitudes. This Joint Strike Fighter concept, which is scheduled to go into production in 2005, will greatly improve the range, capability, maneuverability, and survivability of fighter aircraft, and the production program could ultimately be worth $100 billion. The test program was a team effort between Lewis and Lockheed Martin Tactical Aircraft Systems. Testing was completed in September 1997, several weeks ahead of schedule, allowing Lockheed additional time to review the results and analysis data before the next test and resulting in significant cost savings for Lockheed. Several major milestones related to dynamic and steady-state data acquisition and overall model performance were reached during this model test. Results from this program will contribute to both the concept demonstration phase and the production aircraft.

  13. A design study of a reaction control system for a V/STOL fighter/attack aircraft

    NASA Technical Reports Server (NTRS)

    Beard, B. B.; Foley, W. H.

    1983-01-01

    Attention is given to a short takeoff vertical landing (STOVL) aircraft reaction control system (RCS) design study. The STOVL fighter/attack aircraft employs an existing turbofan engine, and its hover requirement places a premium on weight reduction, which eliminates prospective nonairbreathing RCSs. A simple engine compressor bleed RCS degrades overall performance to an unacceptable degree, and the supersonic requirement precludes the large volume alternatives of thermal or ejector thrust augmentation systems as well as the ducting of engine exhaust gases and the use of a dedicated turbojet. The only system which addressed performance criteria without requiring major engine modifications was a dedicated load compressor driven by an auxilliary power unit.

  14. X-36 Taking off During First Flight

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The X-36 remotely piloted aircraft lifts off on its first flight, May 17, 1997, at NASA's Dryden Flight Research Center, Edwards, California. The aircraft flew for five minutes and reached an altitude of approximately 4,900 feet. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet

  15. Brachyury expression in tailless Molgulid ascidian embryos.

    PubMed

    Takada, Norio; York, Jonathan; Davis, J Muse; Schumpert, Brenda; Yasuo, Hitoyoshi; Satoh, Nori; Swalla, Billie J

    2002-01-01

    The T-box transcription factor gene Brachyury is important for the differentiation of notochord in all chordates, including the ascidians Halocynthia roretzi and Ciona intestinalis. We isolated Brachyury from molgulid ascidians, which have evolved tailless larvae multiple times independently, and found the genes appear functional by cDNA sequence analyses. We then compared the expression of Mocu-Bra in tailed Molgula oculata embryos to two tailless species, Molgula occulta (Mocc-Bra) and Molgula tectiformis (Mt-Bra). Here we show that both tailless species express Brachyury in the notochord lineage during embryogenesis. Initial expression of Mocu-Bra is normal in tailed M. oculata embryos; 10 precursor notochord cells divide twice to result in 40 notochord cells that converge and extend to make a notochord down the center of the tail. In contrast, in tailless Molgula occulta, Mocc-Bra expression disappears prematurely, and there is only one round of division, resulting in 20 cells in the final notochord lineage that never converge or extend. In M. occulta x M. oculata hybrid embryos, expression of Mocu-Bra is prolonged, and the embryos form a tail with 20 notochord cells that converge and extend normally. However, in Molgula tectiformis, a different tailless ascidian, Mt-Bra was expressed only in the 10 notochord precursor cells, which never divide, converge, or extend. In summary, neither Brachyury function nor the early establishment of the notochord lineage appears to be impaired in tailless embryos. In light of these results, we are continuing to investigate how and why notochord development is lost in tailless molgulid ascidian embryos.

  16. X-36 in Flight over Mojave Desert

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The unusual lines of the X-36 technology demonstrator contrast sharply with the desert floor as the remotely piloted aircraft scoots across the California desert at low altitude during a research flight on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with

  17. Study of aerodynamic technology for VSTOL fighter/attack aircraft, phase 1

    NASA Technical Reports Server (NTRS)

    Driggers, H. H.

    1978-01-01

    A conceptual design study was performed of a vertical attitude takeoff and landing (VATOL) fighter/attack aircraft. The configuration has a close-coupled canard-delta wing, side two-dimensional ramp inlets, and two augmented turbofan engines with thrust vectoring capability. Performance and sensitivities to objective requirements were calculated. Aerodynamic characteristics were estimated based on contractor and NASA wind tunnel data. Computer simulations of VATOL transitions were performed. Successful transitions can be made, even with series post-stall instabilities, if reaction controls are properly phased. Principal aerodynamic uncertainties identified were post-stall aerodynamics, transonic aerodynamics with thrust vectoring and inlet performance in VATOL transition. A wind tunnel research program was recommended to resolve the aerodynamic uncertainties.

  18. Forward Arming and Refueling Points for Fighter Aircraft: Power Projection in an Antiaccess Environment

    DTIC Science & Technology

    2014-10-01

    Arming and Refueling Points for Fighter Aircraft Feature Fifth-Generation Doolittle Raid If we should have to fight, we should be prepared to do so from...the neck up instead of from the neck down. —Gen Jimmy Doolittle The famous Doolittle Raid during World War II offers a superb exam- ple of how an...innovative concept can lead to strategic effects. On 18 April 1942, just four months after the Japanese attack on Pearl Harbor, Lt Col Jimmy Doolittle

  19. Recent developments in rotary-balance testing of fighter aircraft configurations at NASA Ames Research Center

    NASA Technical Reports Server (NTRS)

    Malcolm, G. N.; Schiff, L. B.

    1985-01-01

    Two rotary balance apparatuses were developed for testing airplane models in a coning motion. A large scale apparatus, developed for use in the 12-Foot Pressure Wind tunnel primarily to permit testing at high Reynolds numbers, was recently used to investigate the aerodynamics of 0.05-scale model of the F-15 fighter aircraft. Effects of Reynolds number, spin rate parameter, model attitude, presence of a nose boom, and model/sting mounting angle were investigated. A smaller apparatus, which investigates the aerodynamics of bodies of revolution in a coning motion, was used in the 6-by-6 foot Supersonic Wind Tunnel to investigate the aerodynamic behavior of a simple representation of a modern fighter, the Standard Dynamic Model (SDM). Effects of spin rate parameter and model attitude were investigated. A description of the two rigs and a discussion of some of the results obtained in the respective test are presented.

  20. Flight Dynamic Simulation of Fighter In the Asymmetric External Store Release Process

    NASA Astrophysics Data System (ADS)

    Safi’i, Imam; Arifianto, Ony; Nurohman, Chandra

    2018-04-01

    In the fighter design, it is important to evaluate and analyze the flight dynamic of the aircraft earlier in the development process. One of the case is the dynamics of external store release process. A simulation tool can be used to analyze the fighter/external store system’s dynamics in the preliminary design stage. This paper reports the flight dynamics of Jet Fighter Experiment (JF-1 E) in asymmetric Advance Medium Range Air to Air Missile (AMRAAM) release process through simulations. The JF-1 E and AIM 120 AMRAAAM models are built by using Advanced Aircraft Analysis (AAA) and Missile Datcom software. By using these softwares, the aerodynamic stability and control derivatives can be obtained and used to model the dynamic characteristic of the fighter and the external store. The dynamic system is modeled by using MATLAB/Simulink software. By using this software, both the fighter/external store integration and the external store release process is simulated, and the dynamic of the system can be analyzed.

  1. Integrated Unit Deployments: Rethinking Air National Guard Fighter Mobilizations

    DTIC Science & Technology

    2016-06-01

    INTEGRATED UNIT DEPLOYMENTS: RETHINKING AIR NATIONAL GUARD FIGHTER MOBILIZATIONS BY MAJOR ANDREW P. JACOB A THESIS...This study comprises an analysis of the mobilization and deployment of Air National Guard fighter aircraft units in a search for an efficient and... mobilization . This thesis suggests that Integrated Unit Deployments will provide the balance between Air National Guard overseas deployments and

  2. Core temperature of tailless rats exposed to centrifugation

    NASA Technical Reports Server (NTRS)

    Monson, C. B.; Oyama, J.

    1984-01-01

    The role of the tail in the altered thermoregulation of rats during acute exposure to hypergravity was investigated, using groups of rats of two ages: 55 days (young) and 138 days (old). Rectal and foot temperature changes were measured in intact and tailless rats subjected to 1 h centrifugation of 2.8 G, with preceding (1 h) and following (1-3 h) 1 G periods. At 22 C, the loss of body heat from the tail per se does not measurably contribute to the hypothermia induced by hypergravity. However, the heat loss from the feet was greater in the tailless rats than in the intact rats from the young group of animals, although there was no significant difference between the tailless and intact rats in the old animal group. It is concluded that the inhibition of heat production is a significant factor in the hypothermia of centrifuged tailless rats, as it has been previously shown to be in the intact animals.

  3. Alternatives for Modernizing U.S. Fighter Forces

    DTIC Science & Technology

    2009-05-01

    Plans for Modernizing Fighter Forces xS -2. The Possible Role of the F-22 Program in Mitigating the Air Force’s Projected Inventory Shortfall xvi1- 1 ... Northrop Grumman won that competition with its proposal for an aircraft based on the RQ-4 Global Hawk. 38 ALTERNATIVES FOR MODERNIZING U.S. FIGHTER...flyable demonstrator for exploring technologies that could lead to an operational UCAV-N, was rolled out by Northrop Grumman in December 2008. Its

  4. Application of Piloted Simulation to High-Angle-of-Attack Flight-Dynamics Research for Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    Ogburn, Marilyn E.; Foster, John V.; Hoffler, Keith D.

    2005-01-01

    This paper reviews the use of piloted simulation at Langley Research Center as part of the NASA High-Angle-of-Attack Technology Program (HATP), which was created to provide concepts and methods for the design of advanced fighter aircraft. A major research activity within this program is the development of the design processes required to take advantage of the benefits of advanced control concepts for high-angle-of-attack agility. Fundamental methodologies associated with the effective use of piloted simulation for this research are described, particularly those relating to the test techniques, validation of the test results, and design guideline/criteria development.

  5. On the nonlinear aerodynamic and stability characteristics of a generic chine-forebody slender-wing fighter configuration

    NASA Technical Reports Server (NTRS)

    Erickson, Gary E.; Brandon, Jay M.

    1987-01-01

    An exploratory investigation was conducted of the nonlinear aerodynamic and stability characteristics of a tailless generic fighter configuration featuring a chine-shaped forebody coupled to a slender cropped delta wing in the NASA Langley Research Center's 12-Foot Low-Speed Wind Tunnel. Forebody and wing vortex flow mechanisms were identified through off-body flow visualizations to explain the trends in the longitudinal and lateral-directional characteristics at extreme attitudes (angles of attack and sideslip). The interactions of the vortical motions with centerline and wing-mounted vertical tail surfaces were studied and the flow phenomena were correlated with the configuration forces and moments. Single degree of freedom, free-to-roll tests were used to study the wing rock susceptibility of the generic fighter model. Modifications to the nose region of the chine forebody were examined and fluid mechanisms were established to account for their ineffectiveness in modulating the highly interactive forebody and wing vortex systems.

  6. Icing Frequencies Experienced During Climb and Descent by Fighter-Interceptor Aircraft

    NASA Technical Reports Server (NTRS)

    Perkins, Porter J.

    1958-01-01

    Data and analyses are presented on the relative frequencies of occurrence and severity of icing cloud layers encountered by jet aircraft in the climb and descent phases of flights to high altitudes. Fighter-interceptor aircraft operated by the Air Defense Command (USAF) at bases in the Duluth and Seattle areas collected the data with icing meters installed for a l-year period. The project was part of an extensive program conducted by the NACA to collect Icing cloud data for evaluating the icing problem relevant to routine operations. The average frequency of occurrence of icing was found to be about 5 percent of the number of climbs and descents during 1 year of operations The icing encounters were predominantly in the low and middle cloud layers, decreasing above 15,000 feet to practically none above 25,000 feet. The greatest thickness of ice that would accumulate on any aircraft component (as indicated by the accretion on a small object) was measured with the icing meters. The ice thicknesses on a small sensing probe averaged less than 1/32 inch and did not exceed 1/2 inch. Such accumulations are relatively small when compared with those that can form during horizontal flight in icing clouds. The light accretions resulted from relatively steep angles of flight through generally thin cloud layers. Because of the limited statistical reliability of the results, an analysis was made using previous statistics on icing clouds below an altitude of 20,000 feet to determine the general icing severity probabilities. The calculations were made using adiabatic lifting as a basis to establish the liquid-water content. Probabilities of over-all ice accretions on a small object as a function of airspeed and rate of climb were computed from the derived water contents. These results were then combined with the probability of occurrence of icing in order to give the icing severity that can be expected for routine aircraft operations.

  7. Fighter Pilot Ejection Study as an Educational Tool

    ERIC Educational Resources Information Center

    Robinson, Garry; Jovanoski, Zlatko

    2010-01-01

    In this article, we apply the well-known equations of projectile motion to the case of a fighter pilot ejecting from an aircraft, the aim being to establish under what conditions there is danger of impact with the rear vertical stabilizer. The drag force on the pilot after ejection is assumed to vary as the velocity squared and the aircraft motion…

  8. Large-Scale V/STOL Experimental Investigations of an Ejector-Lift Fighter and a Twin Tilt-Nacelle Transport

    NASA Technical Reports Server (NTRS)

    Dudley, Michael R.

    2016-01-01

    In the 1980s NASA Aeronautics was actively involved in full-scale wind tunnel testing of promising VSTOL aircraft concepts. This presentation looks at two, a multi-role fighter and a subsonic tactical transport. Their strengths and weaknesses are discussed with some of the rationale that ultimately led to the selection of competing concepts for production, namely the V-22 Osprey and the F-35 Lightning. The E7-A STOVL multi-role fighter was the product of an aircraft development program in the late 1980s by NASA, the Defense Advanced Research Projects Agency (DARPA), the Canadian Department of Industry Science and Technology (DIST), and industry partners General Dynamics and Boeing Dehavilland. The program was conducted an in response to increasing US-UK interest in supersonic STOVL fighters. The objective was to design an aircraft that could replace most existing close air support-air combat fighters with a single aircraft that had some of the qualities of an air superiority fighter and the deployment flexibility of a VSTOL aircraft. The resulting E7-A concept was a delta-wing supersonic fighter that used a fuselage-mounted thrust augmenting ejector and a ventral deflecting jet nozzle for vertical lift. The Grumman Aircraft Company, the Navy, and NASA developed the Design-698 (D-698) subsonic tactical transport in response to the Navy's Type A VSTOL utility aircraft requirement. The objective was to develop a subsonic utility transport with the operational flexibility of a helicopter, but with greater speed and range. The D-698 employs two high-bypass turbofan engines mounted on a dumbbell that rotates through ninety degrees for vertical takeoff and cruise flight. Movable vanes positioned in the exhaust flow provide control in hover with the need for reaction control jets. The presentations concluding comments suggest that technology advances in the last thirty-years may justify the value of revisiting some of these concepts.

  9. Industrial approach to piezoelectric damping of large fighter aircraft components

    NASA Astrophysics Data System (ADS)

    Simpson, John; Schweiger, Johannes

    1998-06-01

    Different concepts to damp structural vibrations of the vertical tail of fighter aircraft are reported. The various requirements for a vertical tail bias an integrated approach for the design. Several active vibrations suppression concepts had been investigated during the preparatory phase of a research program shared by Daimler-Benz Aerospace Military Aircraft (Dasa), Daimler-Benz Forschung (DBF) and Deutsche Forschungsandstalt fuer Luftund Raumfahrt (DLR). Now in the main phase of the programme, four concepts were finally chosen: two concepts with aerodynamic control surfaces and two concepts with piezoelectric components. One piezo concept approach will be described rigorously, the other concepts are briefly addressed. In the Dasa concept, thin surface piezo actuators are set out carefully to flatten the dynamic portion of the combined static and dynamic maximum bending moment loading case directly in the shell structure. The second piezo concept by DLR involves pre-loaded lead zirconate titanate (PZT)-block actuators at host structure fixtures. To this end a research apparatus was designed and built as a full scale simplified fin box with carbon fiber reinformed plastic skins and an aluminium stringer-rib substructure restrained by relevant aircraft fixtures. It constitutes a benchmark 3D-structural impedance. The engineering design incorporates 7kg of PZT surface actuators. The structural system then should be excited to more than 15mm tip displacement amplitude. This prepares the final step to total A/C integration. Typical analysis methods using cyclic thermal analogies adapted to induced load levels are compared. Commercial approaches leading onto basic state space model interpretation wrt. actuator sizing and positioning, structural integrity constraints, FE-validation and testing are described. Both piezoelectric strategies are aimed at straight open-loop performance related to concept weight penalty and input electric power. The required actuators, power

  10. Historical development of worldwide supersonic aircraft

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1979-01-01

    Aerodynamic problems in the development of supersonic aircraft, their solutions, and innovative design features are presented. Studies of compressibility, introduction of jets, supersonic phenomena, transonic drag and lift, longitudinal and directional stability, dynamic pressure fields, and advent of the supersonic fighter are discussed. The flight research aircraft such as the Bell X-1 and the Douglas-558, the century series models, reconnaissance aircraft, the multimission tactical fighter, and the current generation fighters such as F-16 and F-18 are described. The SCAT program is considered, along with supersonic developments in Great Britain, France, and USSR. It is concluded that the sonic boom still appears to be an inherent problem of supersonic flight that particularly affects overland commercial flight, and efforts continue for increased efficiency for economic and performance gains and increased safety for military and civilian aircraft.

  11. [Comparative analysis on data of nasal sinus between helicopter and(strike) fighter pilots under physical examination for change to new-type aircraft].

    PubMed

    Xu, Xianrong; Ma, Xiaoli; Zhang, Yang; Xiong, Wei

    2012-01-01

    To comparatively analyze the disease data of nasal sinus between helicopter and (strike) fighter pilots under flying qualification, and then to provide references for aeromedical support as a significant part of new logistics service union in army, The CT data of nasal sinus in 138 pilots who accepted physical examination for change to new-type aircraft, were collected included 46 cases of helicopter pilots and 92 cases of (strike)fighter pilots). The incidence of chronic sinusitis and cyst of nasal sinus were computed respectively in helicopter pilots and (strike)fighter pilots. (1) Fourteen cases suffered from chronic sinusitis (6 cases of maxillary sinusitis, 4 cases of ethmoiditis and 4 cases of maxillary sinusitis and ethmoiditis) in helicopter pilots whose incidence rate of chronic sinusitis was 30.4% (14/46). Of which, 3 cases of antracele were treated. Twelve cases suffered from chronic sinusitis (8 cases of maxillary sinusitis, 1 case of ethmoiditis, 3 cases of maxillary sinusitis and ethmoiditis) in (strike)fighter pilots whose incidence of chronic sinusitis was 13.0% (12/92). Of which, 1 case of antracele was treated. The incidence of chronic sinusitis was higher in helicopter pilots than (strike) fighters pilots (Chi2 = 6.07, P < 0.05). (2) Four cases suffered from unilateral mucosa cysts in maxillary sinus in helicopter pilots whose incidence of cyst of nasal sinus was 8.7% (4/46). Ten cases suffered from mucosa cysts in maxillary sinus (unilateral 8 cases and bilateral 2 cases) in (strike) fighters pilots whose incidence of cyst of nasal sinus was 10.87% (10/92). The difference of the incidence of cyst of nasal sinus was not statistically significant between the helicopter pilots and(strike)fighters pilots. The cysts of nasal sinus did not need treatment in 14 cases of this group data. The incidence of symptomless chronic sinusitis and cyst of nasal sinus are high in pilots. It is related with repeatedly changes of atmosphere pressure during flying

  12. Development of an agility assessment module for preliminary fighter design

    NASA Technical Reports Server (NTRS)

    Ngan, Angelen; Bauer, Brent; Biezad, Daniel; Hahn, Andrew

    1996-01-01

    A FORTRAN computer program is presented to perform agility analysis on fighter aircraft configurations. This code is one of the modules of the NASA Ames ACSYNT (AirCraft SYNThesis) design code. The background of the agility research in the aircraft industry and a survey of a few agility metrics are discussed. The methodology, techniques, and models developed for the code are presented. FORTRAN programs were developed for two specific metrics, CCT (Combat Cycle Time) and PM (Pointing Margin), as part of the agility module. The validity of the code was evaluated by comparing with existing flight test data. Example trade studies using the agility module along with ACSYNT were conducted using Northrop F-20 Tigershark and McDonnell Douglas F/A-18 Hornet aircraft models. The sensitivity of thrust loading and wing loading on agility criteria were investigated. The module can compare the agility potential between different configurations and has the capability to optimize agility performance in the preliminary design process. This research provides a new and useful design tool for analyzing fighter performance during air combat engagements.

  13. Development and analysis of a STOL supersonic cruise fighter concept

    NASA Technical Reports Server (NTRS)

    Dollyhigh, S. M.; Foss, W. E., Jr.; Morris, S. J., Jr.; Walkley, K. B.; Swanson, E. E.; Robins, A. W.

    1984-01-01

    The application of advanced and emerging technologies to a fighter aircraft concept is described. The twin-boom fighter (TBF-1) relies on a two dimensional vectoring/reversing nozzle to provide STOL performance while also achieving efficient long range supersonic cruise. A key feature is that the propulsion package is placed so that the nozzle hinge line is near the aircraft center-of-gravity to allow large vector angles and, thus, provide large values of direct lift while minimizing the moments to be trimmed. The configurations name is derived from the long twin booms extending aft of the engine to the twin vertical tails which have a single horizontal tail mounted atop and between them. Technologies utilized were an advanced engine (1985 state-of-the-art), superplastic formed/diffusion bonded titanium structure, advanced controls/avionics/displays, supersonic wing design, and conformal weapons carriage. The integration of advanced technologies into this concept indicate that large gains in takeoff and landing performance, maneuver, acceleration, supersonic cruise speed, and range can be acieved relative to current fighter concepts.

  14. A strategy for in-flight measurements of physiology of pilots of high-performance fighter aircraft.

    PubMed

    West, John B

    2013-07-01

    Some pilots flying modern high-performance fighter aircraft develop "hypoxia-like" incidents characterized by short periods of confusion and cognitive impairment. The problem is serious and recently led to the grounding of a fleet of aircraft. Extensive discussions of the incidents have taken place but some people believe that there is inadequate data to determine the cause. There is a tremendous disconnect between what is known about the function of the aircraft and the function of the pilot. This paper describes a plan for measuring the inspired and expired Po2 and Pco2 in the pilot's mask, the inspiratory flow rate, and pressure in the mask. A critically important requirement is that the interference with the function of the pilot is minimal. Although extensive physiological measurements were previously made on pilots in ground-based experiments such as rapid decompression in an altitude chamber and increased acceleration on a centrifuge, in-flight measurements of gas exchange have not been possible until now primarily because of the lack of suitable equipment. The present paper shows how the recent availability of small, rapidly responding oxygen and carbon dioxide analyzers make sophisticated in-flight measurements feasible. The added information has the potential of greatly improving our knowledge of pilot physiology, which could lead to an explanation for the incidents.

  15. Aircraft Electric Secondary Power

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

  16. Future Carrier-Based Tactical Aircraft Study

    DOT National Transportation Integrated Search

    1996-03-01

    This report describes an aircraft database which was developed to identify technology trends for several classes of tactical naval aircraft, including subsonic attack, supersonic fighter, and supersonic multimission aircraft classes. This study used ...

  17. Aerodynamic Characteristics and Flying Qualities of a Tailless Triangular-wing Airplane Configuration as Obtained from Flights of Rocket-propelled Models at Transonic and Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Mitcham, Grady L; Stevens, Joseph E; Norris, Harry P

    1956-01-01

    A flight investigation of rocket-powered models of a tailless triangular-wing airplane configuration was made through the transonic and low supersonic speed range at the Langley Pilotless Aircraft Research Station at Wallops Island, Va. An analysis of the aerodynamic coefficients, stability derivatives, and flying qualities based on the results obtained from the successful flight tests of three models is presented.

  18. McDonnell XF-88B Experimental Jet Fighter

    NASA Image and Video Library

    1955-08-10

    91,591 Overhead view. McDonnell XF-88B Experimental Jet Fighter. Langley used this aircraft in the mid-1950s to explore the potential of a supersonic propeller. Photographed in Engineer in Charge A History of the Langley Aeronautical Laboratory, 1917-1958 by James R. Hansen. Page 508. **Note see L57-2259 for eye level view.

  19. Predicting Tail Buffet Loads of a Fighter Airplane

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.; Pototzky, Anthony S.

    2006-01-01

    Buffet loads on aft aerodynamic surfaces pose a recurring problem on most twin-tailed fighter airplanes: During maneuvers at high angles of attack, vortices emanating from various surfaces on the forward parts of such an airplane (engine inlets, wings, or other fuselage appendages) often burst, immersing the tails in their wakes. Although these vortices increase lift, the frequency contents of the burst vortices become so low as to cause the aft surfaces to vibrate destructively. Now, there exists a new analysis capability for predicting buffet loads during the earliest design phase of a fighter-aircraft program. In effect, buffet pressures are applied to mathematical models in the framework of a finite-element code, complete with aeroelastic properties and working knowledge of the spatiality of the buffet pressures for all flight conditions. The results of analysis performed by use of this capability illustrate those vibratory modes of a tail fin that are most likely to be affected by buffet loads. Hence, the results help in identifying the flight conditions during which to expect problems. Using this capability, an aircraft designer can make adjustments to the airframe and possibly the aerodynamics, leading to a more robust design.

  20. Signaling the End of Deterrence Afforded by Dual Capable Aircraft

    DTIC Science & Technology

    2017-04-06

    INTRODUCTION For more than 60 years, the Unites States and Europe relied on fighter aircraft capable of executing conventional and nuclear strike...missions. Known as dual-capable aircraft (DCA), these fighters were an integral part of the US extended nuclear deterrence strategy in Asia and Europe...force structure, sustainment and modernization by the US and Allied nations allowed tactical nuclear forces to atrophy. Starting in 2010, the US and

  1. Multidisciplinary Techniques and Novel Aircraft Control Systems

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.; Rogers, James L.; Raney, David L.

    2000-01-01

    The Aircraft Morphing Program at NASA Langley Research Center explores opportunities to improve airframe designs with smart technologies. Two elements of this basic research program are multidisciplinary design optimization (MDO) and advanced flow control. This paper describes examples where MDO techniques such as sensitivity analysis, automatic differentiation, and genetic algorithms contribute to the design of novel control systems. In the test case, the design and use of distributed shape-change devices to provide low-rate maneuvering capability for a tailless aircraft is considered. The ability of MDO to add value to control system development is illustrated using results from several years of research funded by the Aircraft Morphing Program.

  2. Multidisciplinary Techniques and Novel Aircraft Control Systems

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.; Rogers, James L.; Raney, David L.

    2000-01-01

    The Aircraft Morphing Program at NASA Langley Research Center explores opportunities to improve airframe designs with smart technologies. Two elements of this basic research program are multidisciplinary design optimization (MDO) and advanced flow control. This paper describes examples where MDO techniques such as sensitivity analysis, automatic differentiation, and genetic algorithms contribute to the design of novel control systems. In the test case, the design and use of distributed shapechange devices to provide low-rate maneuvering capability for a tailless aircraft is considered. The ability of MDO to add value to control system development is illustrated using results from several years of research funded by the Aircraft Morphing Program.

  3. Utilization of an agility assessment module in analysis and optimization of preliminary fighter configuration

    NASA Technical Reports Server (NTRS)

    Ngan, Angelen; Biezad, Daniel

    1996-01-01

    A study has been conducted to develop and to analyze a FORTRAN computer code for performing agility analysis on fighter aircraft configurations. This program is one of the modules of the NASA Ames ACSYNT (AirCraft SYNThesis) design code. The background of the agility research in the aircraft industry and a survey of a few agility metrics are discussed. The methodology, techniques, and models developed for the code are presented. The validity of the existing code was evaluated by comparing with existing flight test data. A FORTRAN program was developed for a specific metric, PM (Pointing Margin), as part of the agility module. Example trade studies using the agility module along with ACSYNT were conducted using a McDonnell Douglas F/A-18 Hornet aircraft model. Tile sensitivity of thrust loading, wing loading, and thrust vectoring on agility criteria were investigated. The module can compare the agility potential between different configurations and has capability to optimize agility performance in the preliminary design process. This research provides a new and useful design tool for analyzing fighter performance during air combat engagements in the preliminary design.

  4. Low-speed wind-tunnel test of a STOL supersonic-cruise fighter concept

    NASA Technical Reports Server (NTRS)

    Coe, Paul L., Jr.; Riley, Donald R.

    1988-01-01

    A wind-tunnel investigation was conducted to examine the low-speed static stability and control characteristics of a 0.10 scale model of a STOL supersonic cruise fighter concept. The concept, referred to as a twin boom fighter, was designed as a STOL aircraft capable of efficient long range supersonic cruise. The configuration name is derived from the long twin booms extending aft of the engine to the twin vertical tails which support a high center horizontal tail. The propulsion system features a two dimensional thrust vectoring exhaust nozzle which is located so that the nozzle hinge line is near the aircraft center of gravity. This arrangement is intended to allow large thrust vector angles to be used to obtain significant values of powered lift, while minimizing pitching moment trim changes. Low speed stability and control information was obtained over an angle of attack range including the stall. A study of jet induced power effects was included.

  5. Development of tailless and all-wing gliders and airplanes

    NASA Technical Reports Server (NTRS)

    Lademann, Robert W E

    1932-01-01

    Tailless airplanes are characterized by having all their control surfaces, especially the elevator, incorporated in the wings. This paper provides a discussion of the history of their development and current state of development.

  6. Stability Result For Dynamic Inversion Devised to Control Large Flexible Aircraft

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.

    2001-01-01

    High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper is an initial attempt to establish global stability results for dynamic inversion methodology as applied to a large, flexible aircraft. This work builds on a previous result for rigid fighter aircraft and adds a new level of complexity that is the flexible aircraft dynamics, which cannot be ignored even in the most basic flight control. The results arise from observations of the control laws designed for a new generation of the High-Speed Civil Transport aircraft.

  7. Aerodynamic characteristics at Mach numbers from 0.6 to 2.16 of a supersonic cruise fighter configuration with a design Mach number of 1.8

    NASA Technical Reports Server (NTRS)

    Shrout, B. L.

    1977-01-01

    An investigation was made in the Langley 8-foot transonic tunnel and the Langley Unitary Plan wind tunnel, over a Mach number range of 0.6 to 2.16, to determine the static longitudinal and lateral aerodynamic characteristics of a model of a supersonic-cruise fighter. The configuration, which is designed for efficient cruise at Mach number 1.8, is a twin-engine tailless arrow-wing concept with a single rectangular inlet beneath the fuselage and outboard vertical tails and ventral fins. It had untrimmed values of lift-drage ratio ranging from 10 at subsonic speeds to 6.4 at the design Mach number. The configuration was statically stable both longitudinally and laterally.

  8. Stealth Aircraft Technology. (Latest Citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The bibliography contains citations concerning design, manufacture, and history of aircraft incorporating stealth technology. Citations focus on construction materials, testing, aircraft performance, and technology assessment. Fighter aircraft, bombers, missiles, and helicopters represent coverage. (Contains 50-250 citations and includes a subject term index and title list.)

  9. Candidate control design metrics for an agile fighter

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.; Bailey, Melvin L.; Ostroff, Aaron J.

    1991-01-01

    Success in the fighter combat environment of the future will certainly demand increasing capability from aircraft technology. These advanced capabilities in the form of superagility and supermaneuverability will require special design techniques which translate advanced air combat maneuvering requirements into design criteria. Control design metrics can provide some of these techniques for the control designer. Thus study presents an overview of control design metrics and investigates metrics for advanced fighter agility. The objectives of various metric users, such as airframe designers and pilots, are differentiated from the objectives of the control designer. Using an advanced fighter model, metric values are documented over a portion of the flight envelope through piloted simulation. These metric values provide a baseline against which future control system improvements can be compared and against which a control design methodology can be developed. Agility is measured for axial, pitch, and roll axes. Axial metrics highlight acceleration and deceleration capabilities under different flight loads and include specific excess power measurements to characterize energy meneuverability. Pitch metrics cover both body-axis and wind-axis pitch rates and accelerations. Included in pitch metrics are nose pointing metrics which highlight displacement capability between the nose and the velocity vector. Roll metrics (or torsion metrics) focus on rotational capability about the wind axis.

  10. Closed-Loop System Identification Experience for Flight Control Law and Flying Qualities Evaluation of a High Performance Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.

    1996-01-01

    This paper highlights some of the results and issues associated with estimating models to evaluate control law design methods and design criteria for advanced high performance aircraft. Experimental fighter aircraft such as the NASA-High Alpha Research Vehicle (HARV) have the capability to maneuver at very high angles of attack where nonlinear aerodynamics often predominate. HARV is an experimental F/A-18, configured with thrust vectoring and conformal actuated nose strakes. Identifying closed-loop models for this type of aircraft can be made difficult by nonlinearities and high order characteristics of the system. In this paper, only lateral-directional axes are considered since the lateral-directional control law was specifically designed to produce classical airplane responses normally expected with low-order, rigid-body systems. Evaluation of the control design methodology was made using low-order equivalent systems determined from flight and simulation. This allowed comparison of the closed-loop rigid-body dynamics achieved in flight with that designed in simulation. In flight, the On Board Excitation System was used to apply optimal inputs to lateral stick and pedals at five angles at attack : 5, 20, 30, 45, and 60 degrees. Data analysis and closed-loop model identification were done using frequency domain maximum likelihood. The structure of identified models was a linear state-space model reflecting classical 4th-order airplane dynamics. Input time delays associated with the high-order controller and aircraft system were accounted for in data preprocessing. A comparison of flight estimated models with small perturbation linear design models highlighted nonlinearities in the system and indicated that the closed-loop rigid-body dynamics were sensitive to input amplitudes at 20 and 30 degrees angle of attack.

  11. CFD validation experiments at McDonnell Aircraft Company

    NASA Technical Reports Server (NTRS)

    Verhoff, August

    1987-01-01

    Information is given in viewgraph form on computational fluid dynamics (CFD) validation experiments at McDonnell Aircraft Company. Topics covered include a high speed research model, a supersonic persistence fighter model, a generic fighter wing model, surface grids, force and moment predictions, surface pressure predictions, forebody models with 65 degree clipped delta wings, and the low aspect ratio wing/body experiment.

  12. A NASA study of the impact of technology on future carrier based tactical aircraft - Overview

    NASA Technical Reports Server (NTRS)

    Wilson, S. B., III

    1992-01-01

    This paper examines the impact of technology on future carrier based tactical aircraft. The results were used in the Center for Naval Analysis Future Carrier Study. The NASA Team designed three classes of aircraft ('Fighter', 'Attack', and 'Multimission') with two different technology levels. The Multimission aircraft were further analyzed by examining the penalty on the aircraft for both catapult launch/arrested landing recovery (Cat/trap) and short take-off/vertical landing (STOVL). The study showed the so-called STOVL penalty was reduced by engine technology and the next generation Strike Fighter will pay more penalty for Cat/trap than for STOVL capability.

  13. 56TH Fighter Group: ’Wolfpack’ Operations - Air Battle for Berlin.

    DTIC Science & Technology

    1988-04-01

    A pilot from the 63rd FS later reported seeing a yellow nosed fighter attacked and blown up by a Me-109. The 63rd FS pilot subsequently downed that...places one of its aircraft at my disposal by order of the Commanding Officer. Specht and I take off together, with Feldwebel Hauptmann and Sergeant

  14. Wing planform effects at supersonic speeds for an advanced fighter configuration

    NASA Technical Reports Server (NTRS)

    Wood, R. M.; Miller, D. S.

    1984-01-01

    Four advanced fighter configurations, which differed in wing planform and airfoil shape, were investigated in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.60, 1.80, 2.00, and 2.16. Supersonic data were obtained on the four uncambered wings, which were each attached to a single fighter fuselage. The fuselage geometry varied in cross-sectional shape and had two side-mounted, flow-through, half-axisymmetric inlets. Twin vertical tails were attached to the fuselage. The four planforms tested were a 65 deg delta wing, a combination of a 20 deg trapezoidal wing and a 45 deg horizontal tail, a 70 deg/30 deg cranked wing, and a 70 deg/66 deg crank wing, where the angle values refer to the leading-edge sweep angle of the lifting-surface planform. Planform effects on a single fuselage representative of an advanced fighter aircraft were studied. Results show that the highly swept cranked wings exceeded the aerodynamic performance levels, at low lift coefficients, of the 65 deg delta wing and the 20 deg trapezoidal wing at trimmed and untrimmed conditions.

  15. Back symptoms in aviators flying different aircraft.

    PubMed

    Grossman, Alon; Nakdimon, Idan; Chapnik, Leah; Levy, Yuval

    2012-07-01

    Back pain is a common complaint among military aviators of various aircraft. We attempted to define the epidemiologic characteristics of this complaint in military aviators of the Israeli Air Force. Aviators of various aircraft (fighter, attack helicopter, utility helicopter, and transport and cargo) completed 566 questionnaires. The questionnaires included various demographic variables as well as questions specifically addressing type of aircraft, location, and severity of pain. Questionnaires were analyzed according to aircraft type, weekly and total number of flight hours. Back pain was significantly more common among utility and attack helicopter pilots. Compared with only 64.02% of fighter pilots, 89.38% of utility and 74.55% of attack helicopter pilots reported some degree of back pain. Cervical region pain was more common among fighter pilots (47.2%) and utility helicopter pilots (47.3%) compared with attack helicopter (36.4%) and transport (22.3%) pilots. Cervical region pain of moderate-severe degree was more common among utility helicopter pilots (7.1%). Mid and low back pain at all degrees of severity were more common among helicopter pilots. A significant proportion of subjects suffered from pain in multiple regions, particularly among utility helicopter pilots (32.74%). Severity of pain was graded higher in all three regions (cervical, mid, and lower back) in utility helicopter pilots. Utility helicopter pilots have more prevalent and more severe back pain than pilots of other platforms. Yet, it is difficult to make a clear association between type of aircraft and the region of back pain.

  16. Static Longitudinal Stability of a Tandem-Coupled Bomber-Fighter Airplane Configuration Similar to One Proposed by Douglas Aircraft Company, Inc.

    NASA Technical Reports Server (NTRS)

    Hewes, Donald E.

    1950-01-01

    At the request of the Air Materiel Command, an investigation was made in the Langley free-flight tunnel to determine the longitudinal stability and control characteristics of models coupled together in a tandem configuration for aerial refueling similar to one proposed by the Douglas Aircraft Company, Inc. Static force tests were made with 1/20-scale models of the B-29 and F-80 airplanes to determine the effects of rigidly coupling the airplanes together. The Douglas configuration differs from the rigid configuration tested in that it provides for some freedom in pitch and vertical displacement. The force tests showed that, for the bomber alone, the aerodynamic center was 0.21 mean aerodynamic chord behind the center of gravity (stable) but that for the tandem configuration with rigid coupling the aerodynamic center was 0.28 mean aerodynamic chord forward of the center of gravity of the combination (unstable). This reduction in stability was caused by the downwash of the bomber on the fighter. The pitching moment produced by elevator deflection of the bomber was reduced approximately 50 percent by addition of the fighter. Some recent flight tests made in the free-flight tunnel on models in a similar tandem configuration indicated that, with a hinged coupling permitting freedom in pitch, the stability of the combination was better than that obtained with a rigid coupling and was about the same as that for the bomber alone.

  17. Closed-Loop System Identification Experience for Flight Control Law and Flying Qualities Evaluation of a High Performance Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.

    1999-01-01

    This paper highlights some of the results and issues associated with estimating models to evaluate control law design methods and design criteria for advanced high performance aircraft. Experimental fighter aircraft such as the NASA High Alpha Research Vehicle (HARV) have the capability to maneuver at very high angles of attack where nonlinear aerodynamics often predominate. HARV is an experimental F/A-18, configured with thrust vectoring and conformal actuated nose strakes. Identifying closed-loop models for this type of aircraft can be made difficult by nonlinearities and high-order characteristics of the system. In this paper only lateral-directional axes are considered since the lateral-directional control law was specifically designed to produce classical airplane responses normally expected with low-order, rigid-body systems. Evaluation of the control design methodology was made using low-order equivalent systems determined from flight and simulation. This allowed comparison of the closed-loop rigid-body dynamics achieved in flight with that designed in simulation. In flight, the On Board Excitation System was used to apply optimal inputs to lateral stick and pedals at five angles of attack: 5, 20, 30, 45, and 60 degrees. Data analysis and closed-loop model identification were done using frequency domain maximum likelihood. The structure of the identified models was a linear state-space model reflecting classical 4th-order airplane dynamics. Input time delays associated with the high-order controller and aircraft system were accounted for in data preprocessing. A comparison of flight estimated models with small perturbation linear design models highlighted nonlinearities in the system and indicated that the estimated closed-loop rigid-body dynamics were sensitive to input amplitudes at 20 and 30 degrees angle of attack.

  18. Study of a pursuit-evasion guidance law for high performance aircraft

    NASA Technical Reports Server (NTRS)

    Williams, Peggy S.; Menon, P. K. A.; Antoniewicz, Robert F.; Duke, Eugene L.

    1989-01-01

    The study of a one-on-one aircraft pursuit-evasion guidance scheme for high-performance aircraft is discussed. The research objective is to implement a guidance law derived earlier using differential game theory in conjunction with the theory of feedback linearization. Unlike earlier research in this area, the present formulation explicitly recognizes the two-sided nature of the pursuit-evasion scenario. The present research implements the guidance law in a realistic model of a modern high-performance fighter aircraft. Also discussed are the details of the guidance law, implementation in a highly detailed simulation of a high-performance fighter, and numerical results for two engagement geometries. Modifications of the guidance law for onboard implementation is also discussed.

  19. X-4 with Pilot Joe Walker, Preflight Briefing

    NASA Technical Reports Server (NTRS)

    1952-01-01

    In this 1952 photograph NACA test pilot Joe Walker (on left) is seen discussing tests points to be flown on the X-4 aircraft with NACA research engineer Donald Bellman. The X-4 Bantam, a single-place, low swept-wing, semi-tailless aircraft, was designed and built by Northrop Aircraft, Inc. It had no horizontal tail surfaces and its mission was to obtain in-flight data on the stability and control of semi-tailless aircraft at high subsonic speeds. The Northrop X-4, Bantam, was a single-place, swept-wing, semi-tailless airplane designed and built to investigate that configuration at transonic speeds (defined as speeds just below and just above the speed of sound, but in this case, the testing was done primarily at just below the speed of sound). The hope of some aerodynamicists was that eliminating the horizontal tail would also do away with stability problems at transonic speeds resulting from the interaction of supersonic shock waves from the wings and the horizontal stabilizers. Northrop Aircraft, Inc. built two X-4 aircraft, the first of which proved to be mechanically unsound. However, ship number 2, with a thicker trailing edge on the wings and elevon, was very reliable. Ship 1 was then grounded and used as parts for ship 2. While being tested from 1950 to 1953 at the NACA High-Speed Flight Research Station (predecessor of today's NASA Dryden Flight Research Center, Edwards, California), the X-4's semi-tailless configuration exhibited inherent longitudinal stability problems (porpoising) as it approached the speed of sound. The X-4 was a small twinjet-engine airplane that had no horizontal tail surfaces, depending instead on combined elevator and aileron control surfaces (called elevons) for control in pitch and roll attitudes. Data gathered from the aircraft's blunt elevon research were helpful in the design of the Bell X-2, which had ailerons with blunted trailing edges. The NACA X-4 program also provided substantial data on the interactions of combined

  20. Supersonic cruise aircraft research: An annotated bibliography

    NASA Technical Reports Server (NTRS)

    Tuttle, M. H.

    1980-01-01

    This bibliography, with abstracts, consists of 69 publications arranged in chronological order. The material may be useful to those interested in supersonic cruise fighter/penetrator/interceptor airplanes. Two pertinent conferences on military supercruise aircraft are considered as single items; one contains 37 papers and the other 29 papers. In addition, several related bibliographies are included which cover supersonic civil aircraft and military aircraft studies at the Langley Research Center. There is also an author index.

  1. STOVL aircraft simulation for integrated flight and propulsion control research

    NASA Technical Reports Server (NTRS)

    Mihaloew, James R.; Drummond, Colin K.

    1989-01-01

    The United States is in the initial stages of committing to a national program to develop a supersonic short takeoff and vertical landing (STOVL) aircraft. The goal of the propulsion community in this effort is to have the enabling propulsion technologies for this type aircraft in place to permit a low risk decision regarding the initiation of a research STOVL supersonic attack/fighter aircraft in the late mid-90's. This technology will effectively integrate, enhance, and extend the supersonic cruise, STOVL and fighter/attack programs to enable U.S. industry to develop a revolutionary supersonic short takeoff and vertical landing fighter/attack aircraft in the post-ATF period. A joint NASA Lewis and NASA Ames research program, with the objective of developing and validating technology for integrated-flight propulsion control design methodologies for short takeoff and vertical landing (STOVL) aircraft, was planned and is underway. This program, the NASA Supersonic STOVL Integrated Flight-Propulsion Controls Program, is a major element of the overall NASA-Lewis Supersonic STOVL Propulsion Technology Program. It uses an integrated approach to develop an integrated program to achieve integrated flight-propulsion control technology. Essential elements of the integrated controls research program are realtime simulations of the integrated aircraft and propulsion systems which will be used in integrated control concept development and evaluations. This paper describes pertinent parts of the research program leading up to the related realtime simulation development and remarks on the simulation structure to accommodate propulsion system hardware drop-in for real system evaluation.

  2. Flight Testing the X-36: The Test Pilots Perspective

    NASA Technical Reports Server (NTRS)

    Walker, Laurence A.

    1997-01-01

    The X-36 is a 28% scale, remotely piloted research aircraft, designed to demonstrate tailless fighter agility. Powered by a modified Williams International F-112 jet engine, the X-36 uses thrust vectoring and a fly-by-wire control system. Although too small for an onboard pilot, a full-sized remote cockpit was designed to virtually place the test pilot into the aircraft using a variety of innovative techniques. To date, 22 flights have been flown, successfully completing the second phase of testing. Handling qualities have been matching predictions; the test operation is flown similarly to that for full sized manned aircraft. All takeoffs, test maneuvers and landings are flown by the test pilot, affording a greater degree of flexibility and the ability to handle the inevitable unknowns which may occur during highly experimental test programs. The cockpit environment, cues, and display techniques used in this effort have proven to enhance the 'virtual' test pilot's awareness and have helped ensure a successful RPV test program.

  3. Site investigation for 125th fighter interceptor group Florida Air National Guard

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1995-03-01

    A two-step Site Investigation (SI) was conducted to evaluate the nature and extent of environmental contamination that might have resulted from past activities at eight disposal/spill sites at the 125th Fighter Interceptor Group, Florida Air National Guard (FANG) in Jacksonville, Florida. The sites included in the SI are shown on the location map in Figure ES-i and briefly described below: Oil/water separator (OWS) inlets along the aircraft parking apron; Subsurface of aircraft parking apron; Fire training areas, separated for clarity into Site 3E for the east area and Site 3W for the west area; OWS at the Hush House; OWSmore » at the Vehicle Maintenance Building; Area outside the Munitions Building; Trim pad for aircraft run-up; OWS at the Wash Rack.« less

  4. Cervical and lumbar pain and radiological degeneration among fighter pilots: a systematic review and meta-analysis.

    PubMed

    Shiri, Rahman; Frilander, Heikki; Sainio, Markku; Karvala, Kirsi; Sovelius, Roope; Vehmas, Tapio; Viikari-Juntura, Eira

    2015-02-01

    To assess the associations of acceleration force indicators (aircraft type and flight hours) with cervical and lumbar pain and radiological degeneration among fighter pilots. The PubMed, Embase, Scopus and Web of Science databases were searched until October 2013. Twenty-seven studies were included in the review and 20 in the meta-analysis. There were no differences in the prevalence of neck pain (pooled OR=1.07, 95% CI 0.87 to 1.33), cervical disc degeneration (OR=1.26, CI 0.81 to 1.96), low back pain (OR=0.80, CI 0.47 to 1.38) or lumbar disc degeneration (OR=0.87, CI 0.67 to 1.13) between fighter pilots and helicopter or transport/cargo pilots. Moreover, the prevalence of cervical (OR=1.14, CI 0.61 to 2.16) or lumbar (OR=1.05, CI 0.49 to 2.26) disc degeneration did not differ between fighter pilots and non-flying personnel. Most studies did not control their estimates for age and other potential confounders. Among high-performance aircraft pilots, exposure to the highest G-forces was associated with a higher prevalence of neck pain compared with exposure to lower G-forces (pooled OR=3.12, CI 2.08 to 4.67). The studies on the association between flight hours and neck pain reported inconsistent findings. Moreover, looking back over the shoulder (check six) was the most common posture associated with neck pain. Fighter pilots exposed to high G-forces may be at a greater risk for neck pain than those exposed to low G-forces. This finding should be confirmed with better control for confounding. Awkward neck posture may be an important factor in neck pain among fighter pilots. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. Demonstrative Maneuvers for Aircraft Agility Predictions

    DTIC Science & Technology

    2008-03-01

    AIAA Paper 1996-3741. 19. Raymer , Daniel P. Aircraft Design: A Conceptual Approach. American Institute of Aeronautics and Astronautics, Inc., 3rd...Shaw, Robert L. Fighter Combat: Tactics and Maneuvering. Naval Institute Press, Annapolis, MD, 1985. 25. Smith, Steven W. The Scientist and

  6. DEVELOPMENT OF CRITERIA AND METHODS FOR EVALUATING TRAINER AIRCRAFT EFFECTIVENESS.

    ERIC Educational Resources Information Center

    KUSEWITT, J.B.

    THE PURPOSE OF THIS STUDY WAS TO DEVELOP A METHOD FOR DETERMINING OBJECTIVE MEASURES OF TRAINER AIRCRAFT EFFECTIVENESS TO EVALUATE PROGRAM ALTERNATIVES FOR TRAINING PILOTS FOR FLEET FIGHTER AND ATTACK-TYPE AIRCRAFT. THE TRAINING SYLLABUS WAS BASED ON AVERAGE STUDENT ABILITY. THE BASIC PROBLEM WAS TO ESTABLISH QUANTITATIVE TIME-DIFFICULTY…

  7. Experimental aerodynamic characteristics of two V/STOL fighter/attack aircraft configurations at Mach numbers from 0.4 to 1.4

    NASA Technical Reports Server (NTRS)

    Nelms, W. P.; Durston, D. A.; Lummus, J. R.

    1980-01-01

    A wind tunnel test was conducted to measure the aerodynamic characteristics of two horizontal attitude takeoff and landing V/STOL fighter/attack aircraft concepts. In one concept, a jet diffuser ejector was used for the vertical lift system; the other used a remote augmentation lift system (RALS). Wind tunnel tests to investigate the aerodynamic uncertainties and to establish a data base for these types of concepts were conducted over a Mach number range from 0.2 to 2.0. The present report covers tests, conducted in the 11 foot transonic wind tunnel, for Mach numbers from 0.4 to 1.4. Detailed effects of varying the angle of attack (up to 27 deg), angle of sideslip (-4 deg to +8 deg), Mach number, Reynolds number, and configuration buildup were investigated. In addition, the effects of wing trailing edge flap deflections, canard incidence, and vertical tail deflections were explored. Variable canard longitudinal location and different shapes of the inboard nacelle body strakes were also investigated.

  8. Determination of tricresyl phosphate air contamination in aircraft.

    PubMed

    Denola, G; Hanhela, P J; Mazurek, W

    2011-08-01

    Monitoring of tricresyl phosphate (TCP) contamination of cockpit air was undertaken in three types of military aircraft [fighter trainer (FT), fighter bomber (FB), and cargo transport (CT) aircraft]. The aircraft had a previous history of pilot complaints about cockpit air contamination suspected to originate from the engine bleed air supply through the entry of aircraft turbine engine oil (ATO) into the engine compressor. Air samples were collected in flight and on the ground during engine runs using sorbent tubes packed with Porapak Q and cellulose filters. A total of 78 air samples were analysed, from 46 different aircraft, and 48 samples were found to be below the limit of detection. Nine incidents of smoke/odour were identified during the study. The concentrations of toxic o-cresyl phosphate isomers were below the level of detection in all samples. The highest total TCP concentration was 51.3 μg m(-3), while most were generally found to be <5 μg m(-3) compared with the 8-h time-weighted average exposure limit of 100 μg m(-3) for tri-o-cresyl phosphate. The highest concentrations were found at high engine power. Although TCP contamination of cabin/cockpit air has been the subject of much concern in aviation, quantitative data are sparse.

  9. Advanced Aerodynamic Design of Passive Porosity Control Effectors

    NASA Technical Reports Server (NTRS)

    Hunter, Craig A.; Viken, Sally A.; Wood, Richard M.; Bauer, Steven X. S.

    2001-01-01

    This paper describes aerodynamic design work aimed at developing a passive porosity control effector system for a generic tailless fighter aircraft. As part of this work, a computational design tool was developed and used to layout passive porosity effector systems for longitudinal and lateral-directional control at a low-speed, high angle of attack condition. Aerodynamic analysis was conducted using the NASA Langley computational fluid dynamics code USM3D, in conjunction with a newly formulated surface boundary condition for passive porosity. Results indicate that passive porosity effectors can provide maneuver control increments that equal and exceed those of conventional aerodynamic effectors for low-speed, high-alpha flight, with control levels that are a linear function of porous area. This work demonstrates the tremendous potential of passive porosity to yield simple control effector systems that have no external moving parts and will preserve an aircraft's fixed outer mold line.

  10. HCIV-1 and Other Tailless Icosahedral Internal Membrane-Containing Viruses of the Family Sphaerolipoviridae.

    PubMed

    Demina, Tatiana A; Pietilä, Maija K; Svirskaitė, Julija; Ravantti, Janne J; Atanasova, Nina S; Bamford, Dennis H; Oksanen, Hanna M

    2017-02-18

    Members of the virus family Sphaerolipoviridae include both archaeal viruses and bacteriophages that possess a tailless icosahedral capsid with an internal membrane. The genera Alpha- and Betasphaerolipovirus comprise viruses that infect halophilic euryarchaea, whereas viruses of thermophilic Thermus bacteria belong to the genus Gammasphaerolipovirus . Both sequence-based and structural clustering of the major capsid proteins and ATPases of sphaerolipoviruses yield three distinct clades corresponding to these three genera. Conserved virion architectural principles observed in sphaerolipoviruses suggest that these viruses belong to the PRD1-adenovirus structural lineage. Here we focus on archaeal alphasphaerolipoviruses and their related putative proviruses. The highest sequence similarities among alphasphaerolipoviruses are observed in the core structural elements of their virions: the two major capsid proteins, the major membrane protein, and a putative packaging ATPase. A recently described tailless icosahedral haloarchaeal virus, Haloarcula californiae icosahedral virus 1 (HCIV-1), has a double-stranded DNA genome and an internal membrane lining the capsid. HCIV-1 shares significant similarities with the other tailless icosahedral internal membrane-containing haloarchaeal viruses of the family Sphaerolipoviridae . The proposal to include a new virus species, Haloarcula virus HCIV1 , into the genus Alphasphaerolipovirus was submitted to the International Committee on Taxonomy of Viruses (ICTV) in 2016.

  11. Integrated controls pay-off. [for flight/propulsion aircraft systems

    NASA Technical Reports Server (NTRS)

    Putnam, Terrill W.; Christiansen, Richard S.

    1989-01-01

    It is shown that the integration of the propulsion and flight control systems for high performance aircraft can help reduce pilot workload while simultaneously increasing overall aircraft performance. Results of the Highly Integrated Digital Electronic Control (HiDEC) flight research program are presented to demonstrate the emerging payoffs of controls integration. Ways in which the performance of fighter aircraft can be improved through the use of propulsion for primary aircraft control are discussed. Research being conducted by NASA with the F-18 High Angle-of Attack Research Vehicle is described.

  12. Home Cervical Traction to Reduce Neck Pain in Fighter Pilots.

    PubMed

    Chumbley, Eric M; O'Hair, Nicole; Stolfi, Adrienne; Lienesch, Christopher; McEachen, James C; Wright, Bruce A

    2016-12-01

    Most fighter pilots report cervical pain during their careers. Recommendations for remediation lack evidence. We sought to determine whether regular use of a home cervical traction device could decrease reported cervical pain in F-15C pilots. An institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, controlled crossover study was undertaken with 21 male F-15C fighter pilots between February and June 2015. Of the 21 subjects, 12 completed 6 wk each of traction and control, while logging morning, postflying, and post-traction pain. Pain was compared with paired t-tests between the periods, from initial pain scores to postflying, and postflying to post-traction. In the traction phase, initial pain levels increased postflight, from 1.2 (0.7) to 1.6 (1.0) Subsequent post-traction pain levels decreased to 1.3 (0.9), with a corresponding linear decrease in pain relative to pain reported postflight. The difference in pain levels after traction compared to initial levels was not significant, indicating that cervical traction was effective in alleviating flying-related pain. Control pain increased postflight from 1.4 (0.9) to 1.9 (1.3). Daily traction phase pain was lower than the control, but insignificant. To our knowledge, this is the first study of home cervical traction to address fighter pilots' cervical pain. We found a small but meaningful improvement in daily pain rating when using cervical traction after flying. These results help inform countermeasure development for pilots flying high-performance aircraft. Further study should clarify the optimal traction dose and timing in relation to flying.Chumbley EM, O'Hair N, Stolfi A, Lienesch C, McEachen JC, Wright BA. Home cervical traction to reduce neck pain in fighter pilots. Aerosp Med Hum Perform. 2016; 87(12):1010-1015.

  13. Redesigning of a Canard Control Surface of an Advanced Fighter Aircraft: Effect on Buckling and Aerodynamic Behavior

    NASA Astrophysics Data System (ADS)

    Shrivastava, Sachin; Mohite, P. M.

    2015-01-01

    A redesign of canard control-surface of an advanced all-metallic fighter aircraft was carried out by using carbon fibre composite (CFC) for ribs and panels. In this study ply-orientations of CFC structure are optimized using a Genetic-Algorithm (GA) with an objective function to have minimum failure index (FI) according to Tsai-Wu failure criterion. The redesigned CFC structure was sufficiently strong to withstand aerodynamic loads from stress and deflection points of view. Now, in the present work CFC canard structure has been studied for its buckling strength in comparison to existing metallic design. In this study, the existing metallic design was found to be weak in buckling. Upon a detailed investigation, it was revealed that there are reported failures in the vicinity of zones where initial buckling modes are excited as predicted by the finite element based buckling analysis. In view of buckling failures, the redesigned CFC structure is sufficiently reinforced with stringers at specific locations. After providing reinforcements against buckling, the twist and the camber variations of the airfoil are checked and compared with existing structure data. Finally, the modal analysis has been carried out to compare the variation in excitation frequency due to material change. The CFC structure thus redesigned is safe from buckling and aerodynamic aspects as well.

  14. Are You Experienced : A Fresh Look at the Fifth-Generation Fighter Experience Model

    DTIC Science & Technology

    2016-06-01

    13 ANALYSIS………………………………………………………………………………………15 Aircraft Utilization Rates………………………………………………………………...15 Fourth and Fifth Generation TTE Comparison... military service, the United States Air Force embodies the advancements of technology available in the modern age. Fighter aircraft are essential to the...pilot to achieve experience is called Time to 7 Experience ( TTE ). This value divided by the number of inexperienced positions is a squadron’s

  15. Program Fighter: An Evaluation.

    ERIC Educational Resources Information Center

    Hull, David G.; Fowler, Wallace T.

    A computer program for the sizing of subsonic and supersonic fighter planes was adapted for use in an aerospace engineering course at the University of Texas at Austin. FIGHTER uses classroom notation and separate subroutines for different disciplines to implement the conceptual design process. Input consists of a set of design variables and a set…

  16. Moving Base Simulation of an ASTOVL Lift-Fan Aircraft

    DOT National Transportation Integrated Search

    1995-08-01

    Using a generalized simulation model, a moving-base simulation of a lift-fan : short takeoff/vertical landing fighter aircraft was conducted on the Vertical : Motion Simulator at Ames Research Center. Objectives of the experiment were to : (1)assess ...

  17. Aerodynamics Model for a Generic ASTOVL Lift-Fan Aircraft

    DOT National Transportation Integrated Search

    1995-04-01

    This report describes the aerodynamics model used in a simulation model of : an advanced short takeoff and vertical landing lift-far fighter aircraft. The : simulation model was developed for use in piloted evaluations of transition and : hover fligh...

  18. Submersible Aircraft Concept Design Study - Amendment 1. Additional Assessment of Design Risks & Sensitivities within the Original Study, and an Initial Assessment of Key Control Aspects

    DTIC Science & Technology

    2011-02-01

    http://www.redhammer.se/tornado/index.html (3) Aircraft Design: A Conceptual Approach, Daniel P. Raymer , AIAA, 1992 (4) (5) Moran, J., Computational...Fluid Dynamics, Wiley & Sons, 1984. Notes on the Stability and Control of Tailless Airplanes, Robert T. Jones, NACA Technical Note No.837, December

  19. To Err is Human Case Reports of Two Military Aircraft Accidents

    PubMed Central

    Dikshit, Mohan B

    2010-01-01

    It has been postulated that pilot error or in-flight incapacitation may be the main contributory factors to 70–80% of aircraft accidents. Two fatal aircraft accidents are presented in which either of the above possibilities may have played a role. The first case report describes an erroneous decision by a fighter pilot to use a seat position adjustment of the ejection seat leading to fatal injuries when he had to eject from his aircraft. Injuries to the body of the pilot, and observations on the state of his flying clothing and the ejection seat were used to postulate the mechanism of fatal injury and establish the cause of the accident. The second case report describes the sequence of events which culminated in the incapacitation of a fighter pilot while executing a routine manouevre. This resulted in a fatal air crash. Possible contributions of environmental factors which may have resulted in failure of his physiological mechanisms are discussed. PMID:21509093

  20. Investigation into the impact of agility on conceptual fighter design

    NASA Technical Reports Server (NTRS)

    Engelbeck, R. M.

    1995-01-01

    The Agility Design Study was performed by the Boeing Defense and Space Group for the NASA Langley Research Center. The objective of the study was to assess the impact of agility requirements on new fighter configurations. Global trade issues investigated were the level of agility, the mission role of the aircraft (air-to-ground, multi-role, or air-to-air), and whether the customer is Air force, Navy, or joint service. Mission profiles and design objectives were supplied by NASA. An extensive technology assessment was conducted to establish the available technologies to industry for the aircraft. Conceptual level methodology is presented to assess the five NASA-supplied agility metrics. Twelve configurations were developed to address the global trade issues. Three-view drawings, inboard profiles, and performance estimates were made and are included in the report. A critical assessment and lessons learned from the study are also presented.

  1. Aircraft and related factors in crashes involving spatial disorientation: 15 years of U.S. Air Force data.

    PubMed

    Lyons, Terence J; Ercoline, William; O'Toole, Kevin; Grayson, Kevin

    2006-07-01

    Previous studies have determined that spatial disorientation (SD) causes 0.5-23% of aircraft crashes, but SD-related crash and fatality rates in different aircraft types have not been systematically studied. SD crashes for the fiscal years 1990 to 2004 and aircraft sortie numbers for all U.S. Air Force (USAF) aircraft were obtained from the USAF Safety Center. Contingency table analysis and Chi-squared tests were used to evaluate differences in SD rates. SD accounted for 11% of USAF crashes with an overall rate of 2.9 per million sorties and a crash fatality rate of 69%. The SD rate was higher in fighter/attack aircraft and helicopters than in training and transport aircraft. The risk of SD was increased at night with 23% of night crashes being caused by SD. But the SD rate and crash fatality rate were not higher in single-crewmember aircraft. SD risk is significantly increased in helicopters and fighter/attack aircraft and at night. The data suggest that a second crewmember does not protect against SD. Further study of specific SD scenarios could lead to focused interventions for SD prevention.

  2. Flutter optimization in fighter aircraft design

    NASA Technical Reports Server (NTRS)

    Triplett, W. E.

    1984-01-01

    The efficient design of aircraft structure involves a series of compromises among various engineering disciplines. These compromises are necessary to ensure the best overall design. To effectively reconcile the various technical constraints requires a number of design iterations, with the accompanying long elapsed time. Automated procedures can reduce the elapsed time, improve productivity and hold the promise of optimum designs which may be missed by batch processing. Several examples are given of optimization applications including aeroelastic constraints. Particular attention is given to the success or failure of each example and the lessons learned. The specific applications are shown. The final two applications were made recently.

  3. An in-flight investigation of pilot-induced oscillation suppression filters during the fighter approach and landing task

    NASA Technical Reports Server (NTRS)

    Bailey, R. E.; Smith, R. E.

    1982-01-01

    An investigation of pilot-induced oscillation suppression (PIOS) filters was performed using the USAF/Flight Dynamics Laboratory variable stability NT-33 aircraft, modified and operated by Calspan. This program examined the effects of PIOS filtering on the longitudinal flying qualities of fighter aircraft during the visual approach and landing task. Forty evaluations were flown to test the effects of different PIOS filters. Although detailed analyses were not undertaken, the results indicate that PIOS filtering can improve the flying qualities of an otherwise unacceptable aircraft configuration (Level 3 flying qualities). However, the ability of the filters to suppress pilot-induced oscillations appears to be dependent upon the aircraft configuration characteristics. Further, the data show that the filters can adversely affect landing flying qualities if improperly designed. The data provide an excellent foundation from which detail analyses can be performed.

  4. Learning amongst Norwegian Fire-Fighters

    ERIC Educational Resources Information Center

    Sommer, Morten; Nja, Ove

    2011-01-01

    Purpose: The purpose of this study is to reveal and analyse dominant learning processes in emergency response work from the fire-fighters' point of view, and how fire-fighters develop their competence. Design/methodology/approach: This study adopted an explorative approach using participant observation. The objective of this open-minded approach…

  5. Filling the Fighter Gap

    DTIC Science & Technology

    2010-03-18

    1 Filling the Fighter Gap by Major Justin DeMarco, USAF The purpose of this paper is to suggest how the Air Force can mitigate the...estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services...SUBTITLE Filling the Fighter Gap 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER

  6. Fighter agility metrics, research, and test

    NASA Technical Reports Server (NTRS)

    Liefer, Randall K.; Valasek, John; Eggold, David P.

    1990-01-01

    Proposed new metrics to assess fighter aircraft agility are collected and analyzed. A framework for classification of these new agility metrics is developed and applied. A completed set of transient agility metrics is evaluated with a high fidelity, nonlinear F-18 simulation provided by the NASA Dryden Flight Research Center. Test techniques and data reduction methods are proposed. A method of providing cuing information to the pilot during flight test is discussed. The sensitivity of longitudinal and lateral agility metrics to deviations from the pilot cues is studied in detail. The metrics are shown to be largely insensitive to reasonable deviations from the nominal test pilot commands. Instrumentation required to quantify agility via flight test is also considered. With one exception, each of the proposed new metrics may be measured with instrumentation currently available. Simulation documentation and user instructions are provided in an appendix.

  7. Study of aerodynamic technology for single-cruise engine V/STOL fighter/attack aircraft

    NASA Technical Reports Server (NTRS)

    Driggers, H. H.; Powers, S. A.; Roush, R. T.

    1982-01-01

    A conceptual design analysis is performed on a single engine V/STOL supersonic fighter/attack concept powered by a series flow tandem fan propulsion system. Forward and aft mounted fans have independent flow paths for V/STOL operation and series flow in high speed flight. Mission, combat and V/STOL performance is calculated. Detailed aerodynamic estimates are made and aerodynamic uncertainties associated with the configuration and estimation methods identified. A wind tunnel research program is developed to resolve principal uncertainties and establish a data base for the baseline configuration and parametric variations.

  8. High angle-of-attack aerodynamics of a strake-canard-wing V/STOL fighter configuration

    NASA Technical Reports Server (NTRS)

    Durston, D. A.; Schreiner, J. A.

    1983-01-01

    High angle-of-attack aerodynamic data are analyzed for a strake-canard-wing V/STOL fighter configuration. The configuration represents a twin-engine supersonic V/STOL fighter aircraft which uses four longitudinal thrust-augmenting ejectors to provide vertical lift. The data were obtained in tests of a 9.39 percent scale model of the configuration in the NASA Ames 12-Foot Pressure Wind Tunnel, at a Mach number of 0.2. Trimmed aerodynamic characteristics, longitudinal control power, longitudinal and lateral/directional stability, and effects of alternate strake and canard configurations are analyzed. The configuration could not be trimmed (power-off) above 12 deg angle of attack because of the limited pitch control power and the high degree of longitudinal instability (28 percent) at this Mach number. Aerodynamic center location was found to be controllable by varying strake size and canard location without significantly affecting lift and drag. These configuration variations had relatively little effect on the lateral/directional stability up to 10 deg angle of attack.

  9. Aircraft as Research Tools

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Aeronautical research usually begins with computers, wind tunnels, and flight simulators, but eventually the theories must fly. This is when flight research begins, and aircraft are the primary tools of the trade. Flight research involves doing precision maneuvers in either a specially built experimental aircraft or an existing production airplane that has been modified. For example, the AD-1 was a unique airplane made only for flight research, while the NASA F-18 High Alpha Research Vehicle (HARV) was a standard fighter aircraft that was transformed into a one-of-a-kind aircraft as it was fitted with new propulsion systems, flight controls, and scientific equipment. All research aircraft are able to perform scientific experiments because of the onboard instruments that record data about its systems, aerodynamics, and the outside environment. Since the 1970's, NASA flight research has become more comprehensive, with flights involving everything form Space Shuttles to ultralights. NASA now flies not only the fastest airplanes, but some of the slowest. Flying machines continue to evolve with new wing designs, propulsion systems, and flight controls. As always, a look at today's experimental research aircraft is a preview of the future.

  10. Flight experience with manually controlled unconventional aircraft motions

    NASA Technical Reports Server (NTRS)

    Barfield, A. F.

    1978-01-01

    A modified YF-16 aircraft was used to flight demonstrate decoupled modes under the USAF Fighter Control Configured Vehicle (CCV) Program. The direct force capabilities were used to implement seven manually controlled unconventional modes on the aircraft, allowing flat turns, decoupled normal acceleration control, independent longitudinal and lateral translations, uncoupled elevation and azimuth aiming, and blended direct lift. This paper describes the design, development, and flight testing of these control modes. The need for task-tailored mode authorities, gain-scheduling and selected closed-loop design is discussed.

  11. Multiaxis control power from thrust vectoring for a supersonic fighter aircraft model at Mach 0.20 to 2.47

    NASA Technical Reports Server (NTRS)

    Capone, Francis J.; Bare, E. Ann

    1987-01-01

    The aeropropulsive characteristics of an advanced twin-engine fighter aircraft designed for supersonic cruise have been studied in the Langley 16-Foot Tansonic Tunnel and the Lewis 10- by 10-Foot Supersonic Tunnel. The objective was to determine multiaxis control-power characteristics from thrust vectoring. A two-dimensional convergent-divergent nozzle was designed to provide yaw vector angles of 0, -10, and -20 deg combined with geometric pitch vector angles of 0 and 15 deg. Yaw thrust vectoring was provided by yaw flaps located in the nozzle sidewalls. Roll control was obtained from differential pitch vectoring. This investigation was conducted at Mach numbers from 0.20 to 2.47. Angle of attack was varied from 0 to about 19 deg, and nozzle pressure ratio was varied from about 1 (jet off) to 28, depending on Mach number. Increments in force or moment coefficient that result from pitch or yaw thrust vectoring remain essentially constant over the entire angle-of-attack range of all Mach numbers tested. There was no effect of pitch vectoring on the lateral aerodynamic forces and moments and only very small effects of yaw vectoring on the longitudinal aerodynamic forces and moments. This result indicates little cross-coupling of control forces and moments for combined pitch-yaw vectoring.

  12. Aircraft modifications: Assessing the current state of Air Force aircraft modifications and the implications for future military capability

    NASA Astrophysics Data System (ADS)

    Hill, Owen Jacob

    How prepared is the U.S. Air Force to modify its aircraft fleet in upcoming years? Aircraft modernization is a complex interaction of new and legacy aircraft, organizational structure, and planning policy. This research will take one component of modernization: aircraft modification, and apply a new method of analysis in order to help formulate policy to promote modernization. Departing from previous small-sample studies dependent upon weight as a chief explanatory variable, this dissertation incorporates a comprehensive dataset that was constructed for this research of all aircraft modifications from 1996 through 2005. With over 700 modification programs, this dataset is used to examine changes to the current modification policy using policy-response regression models. These changes include separating a codependent procurement and installation schedule, reducing the documentation requirements for safety modifications, and budgeting for aging aircraft modifications. The research then concludes with predictive models for the F-15 and F-16 along with their replacements: the F-22 and F-35 Joint Strike Fighter.

  13. Advanced Airborne Defensive Laser for Incorporation on Strike Fighter Aircraft

    DTIC Science & Technology

    2017-09-01

    Systems within the Pod The Cyclops pod contains several systems working together to perform the high - level functions. The status of these systems must be...by the aircraft is limited, and Cyclops power requirements are high . commercial off-the-shelf (COTS) Ram Air Turbines are available and are...Supply Subsystem The Cyclops pod must generate its own power due to lack of available power from the aircraft; therefore, the Power supply has high

  14. Design and Optimization of a Composite Canard Control Surface of an Advanced Fighter Aircraft under Static Loading

    NASA Astrophysics Data System (ADS)

    Shrivastava, Sachin; Mohite, P. M.

    2015-01-01

    The minimization of weight and maximization of payload is an ever challenging design procedure for air vehicles. The present study has been carried out with an objective to redesign control surface of an advanced all-metallic fighter aircraft. In this study, the structure made up of high strength aluminum, titanium and ferrous alloys has been attempted to replace by carbon fiber composite (CFC) skin, ribs and stiffeners. This study presents an approach towards development of a methodology for optimization of first-ply failure index (FI) in unidirectional fibrous laminates using Genetic-Algorithms (GA) under quasi-static loading. The GAs, by the application of its operators like reproduction, cross-over, mutation and elitist strategy, optimize the ply-orientations in laminates so as to have minimum FI of Tsai-Wu first-ply failure criterion. The GA optimization procedure has been implemented in MATLAB and interfaced with commercial software ABAQUS using python scripting. FI calculations have been carried out in ABAQUS with user material subroutine (UMAT). The GA's application gave reasonably well-optimized ply-orientations combination at a faster convergence rate. However, the final optimized sequence of ply-orientations is obtained by tweaking the sequences given by GA's based on industrial practices and experience, whenever needed. The present study of conversion of an all metallic structure to partial CFC structure has led to 12% of weight reduction. Therefore, the approach proposed here motivates designer to use CFC with a confidence.

  15. Editorial on Future Jet Technologies

    NASA Astrophysics Data System (ADS)

    Gal-Or, Benjamin

    2014-08-01

    Advanced jet engines do not operate in an application vacuum. Their optimal use in advanced military applications drives much of their basic innovative research and development, especially when new needs arise in the rapidly changing domains of stealth-agile, fighter aircraft and tailless-stealth, Jet-Steered, Unmanned Air Vehicles (JS-UAV). For these reasons we periodically update this Journal with new trends that affect, and sometimes control, research and development of future jet-engines. One relevant example is the recently unmasked RQ-180 stealth-tailless drone, which is an improved version of the smaller, RQ-170 captured by Iran. Most important, with the new X-47B/C tailless-stealth JS-UAV, it is to dominate future uses of fuel-efficient jet-engines, especially for operating in dusty environments. The RQ-180 has been secretly designed and funded since 2008. It is based on a classified, 1986, parent Israeli Patents 78402, which protect hundreds design and testing trade secrets taken from 1986 to 1997 by the United States Government (USG) via classified contracts with USG-Contractors Boeing, Lockheed, General Dynamics and General Electric, as revealed by a December 6, 2013 Aviation Week [1-3] and U.S. Court of Appeals for the Federal Circuit, Case 2014-5028, Docket 12 [4]. The new RQ-180 design explains the recent U.S. Air Force ISR shift away from "permissive" environments - such as Iraq and Afghanistan, where non-stealthy Global Hawk and General Atomics' Reaper operate - toward new missions in highly "contested" or strongly "denied" enemy airspaces.

  16. Measuring wildland fire fighter performance with wearable technology.

    PubMed

    Parker, Richard; Vitalis, Antonios; Walker, Robyn; Riley, David; Pearce, H Grant

    2017-03-01

    Wildland (rural) fire fighting is a physically demanding and hazardous occupation. An observational study was conducted to explore the use of new technologies for the field study of fire fighters at wildfires and to understand the work pressures of wildland fire fighting. The research was carried out with two fire fighters at real fires wearing microphones, miniature video cameras, heart rate monitors and GPS units to record their actions and location at wildfire events. The fire fighters were exposed to high physiological workloads (heart rates of up to 180 beats per minute) and walked considerable distances at the fires. Results from this study have been used in presentations to fire fighters and non-operational fire personnel to understand the pressures fire fighters are under and how others complete the fire fighting tasks. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Aircraft Design Software

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Successful commercialization of the AirCraft SYNThesis (ACSYNT) tool has resulted in the creation of Phoenix Integration, Inc. ACSYNT has been exclusively licensed to the company, an outcome of a seven year, $3 million effort to provide unique software technology to a focused design engineering market. Ames Research Center formulated ACSYNT and in working with the Virginia Polytechnic Institute CAD Laboratory, began to design and code a computer-aided design for ACSYNT. Using a Joint Sponsored Research Agreement, Ames formed an industry-government-university alliance to improve and foster research and development for the software. As a result of the ACSYNT Institute, the software is becoming a predominant tool for aircraft conceptual design. ACSYNT has been successfully applied to high- speed civil transport configuration, subsonic transports, and supersonic fighters.

  18. Application of thrusting ejectors to tactical aircraft having vertical lift and short-field capability

    NASA Technical Reports Server (NTRS)

    Koenig, D. G.; Stoll, F.; Aoyagi, K.

    1981-01-01

    The status of ejector development in terms of application to V/STOL aircraft is reported in three categories: aircraft systems and ejector concepts; ejector performance including prediction techniques and experimental data base available; and, integration of the ejector with complete aircraft configurations. Available prediction techniques are reviewed and performance of three ejector designs with vertical lift capability is summarized. Applications of the 'fuselage' and 'short diffuser' ejectors to fighter aircraft are related to current and planned research programs. Recommendations are listed for effort needed to evaluate installed performance.

  19. Pressure breathing in fighter aircraft for G accelerations and loss of cabin pressurization at altitude--a brief review.

    PubMed

    Lauritzsen, Lars P; Pfitzner, John

    2003-04-01

    The purpose of this brief review is to outline the past and present use of pressure breathing, not by patients but by fighter pilots. Of the historical and recent references quoted, most are from aviation-medicine journals that are not often readily available to anesthesiologists. Pressure breathing at moderate levels of airway pressure gave World War II fighter pilots a tactical altitude advantage. With today's fast and highly maneuverable jet fighters, very much higher airway pressures of the order of 8.0 kPa (identical with 60 mmHg) are used. They are used in conjunction with a counterpressure thoracic vest and an anti-G suit for the abdomen and lower body. Pressurization is activated automatically in response to +Gz accelerations, and to a potentially catastrophic loss of cabin pressurization at altitude. During +Gz accelerations, pressure breathing has been shown to maintain cerebral perfusion by raising the systemic arterial pressure, so increasing the level of G-tolerance that is afforded by the use of anti-G suits and seat tilt-back angles alone. This leaves the pilot less reliant on rigorous, and potentially distracting, straining maneuvers. With loss of cabin pressurization at altitude, pressure breathing of 100% oxygen at high airway pressures enables the pilot's alveolar PO(2) to be maintained at a safe level during emergency descent. Introduced in military aviation, pressure breathing for G-tolerance and pressure breathing for altitude presented as concepts that may be of general physiological interest to many anesthesiologists.

  20. F-35 Joint Strike Fighter Aircraft (F-35)

    DTIC Science & Technology

    2013-12-01

    Critical Design Review; announcing the decision to terminate development of an alternate Helmet Mounted Display System (HMDS); completing the 2nd F-35B...the 100th aircraft from the production facility at Fort Worth, Texas; and resolving lingering technical design shortfalls to include the F-35C...emphasis on: regular design reviews, systems engineering discipline, software development planning with baseline review boards, and focused metrics

  1. Performance Evaluation Method for Dissimilar Aircraft Designs

    NASA Technical Reports Server (NTRS)

    Walker, H. J.

    1979-01-01

    A rationale is presented for using the square of the wingspan rather than the wing reference area as a basis for nondimensional comparisons of the aerodynamic and performance characteristics of aircraft that differ substantially in planform and loading. Working relationships are developed and illustrated through application to several categories of aircraft covering a range of Mach numbers from 0.60 to 2.00. For each application, direct comparisons of drag polars, lift-to-drag ratios, and maneuverability are shown for both nondimensional systems. The inaccuracies that may arise in the determination of aerodynamic efficiency based on reference area are noted. Span loading is introduced independently in comparing the combined effects of loading and aerodynamic efficiency on overall performance. Performance comparisons are made for the NACA research aircraft, lifting bodies, century-series fighter aircraft, F-111A aircraft with conventional and supercritical wings, and a group of supersonic aircraft including the B-58 and XB-70 bomber aircraft. An idealized configuration is included in each category to serve as a standard for comparing overall efficiency.

  2. Turboprop aircraft against terrorism: a SWOT analysis of turboprop aircraft in CAS operations

    NASA Astrophysics Data System (ADS)

    Yavuz, Murat; Akkas, Ali; Aslan, Yavuz

    2012-06-01

    Today, the threat perception is changing. Not only for countries but also for defence organisations like NATO, new threat perception is pointing terrorism. Many countries' air forces become responsible of fighting against terorism or Counter-Insurgency (COIN) Operations. Different from conventional warfare, alternative weapon or weapon systems are required for such operatioins. In counter-terrorism operations modern fighter jets are used as well as helicopters, subsonic jets, Unmanned Aircraft Systems (UAS), turboprop aircraft, baloons and similar platforms. Succes and efficiency of the use of these platforms can be determined by evaluating the conditions, the threats and the area together. Obviously, each platform has advantages and disadvantages for different cases. In this research, examples of turboprop aircraft usage against terrorism and with a more general approach, turboprop aircraft for Close Air Support (CAS) missions from all around the world are reviewed. In this effort, a closer look is taken at the countries using turboprop aircraft in CAS missions while observing the fields these aircraft are used in, type of operations, specifications of the aircraft, cost and the maintenance factors. Thus, an idea about the convenience of using these aircraft in such operations can be obtained. A SWOT analysis of turboprop aircraft in CAS operations is performed. This study shows that turboprop aircraft are suitable to be used in counter-terrorism and COIN operations in low threat environment and is cost benefical compared to jets.

  3. Studies of aerodynamic technology for VSTOL fighter/attack aircraft

    NASA Technical Reports Server (NTRS)

    Nelms, W. P.

    1978-01-01

    The paper summarizes several studies to develop aerodynamic technology for high performance VSTOL aircraft anticipated after 1990. A contracted study jointly sponsored by NASA-Ames and David Taylor Naval Ship Research and Development Center is emphasized. Four contractors analyzed two vertical-attitude and three horizontal-attitude takeoff and landing concepts with gross weights ranging from about 10433 kg (23,000 lb) to 17236 kg (38,000 lb). The aircraft have supersonic capability, high maneuver performance (sustained load factor 6.2 at Mach 0.6, 3048 m (10,000 ft)) and a 4536 kg (10,000-lb) STO overload capability. The contractors have estimated the aerodynamics and identified aerodynamic uncertainties associated with their concept. Example uncertainties relate to propulsion-induced flows, canard-wing interactions, and top inlets. Wind-tunnel research programs were proposed to investigate these uncertainties.

  4. A Bomber Fighter Duel (II)

    DTIC Science & Technology

    1949-07-25

    RAND 1 RESEARCH MEMORANDUM c: . A BOMBER FIGHTER DUEL (II) David Blackwell and Max Shiffiaan HM-193 • 25 July 1949 Copy No./c^JZ. . Thi...II) David Blackwell and Max Shiffman 0. Summary. This memorandum completes the study’of the fighteir- bomber duel described in RM-l65i» The... duel is one in which a fighter fires a single rocket burst at a bomber, which has limited ammunition, and defends itself by intermittent firing. It

  5. Design and stable flight of a 21 g insect-like tailless flapping wing micro air vehicle with angular rates feedback control.

    PubMed

    Phan, Hoang Vu; Kang, Taesam; Park, Hoon Cheol

    2017-04-04

    An insect-like tailless flapping wing micro air vehicle (FW-MAV) without feedback control eventually becomes unstable after takeoff. Flying an insect-like tailless FW-MAV is more challenging than flying a bird-like tailed FW-MAV, due to the difference in control principles. This work introduces the design and controlled flight of an insect-like tailless FW-MAV, named KUBeetle. A combination of four-bar linkage and pulley-string mechanisms was used to develop a lightweight flapping mechanism that could achieve a high flapping amplitude of approximately 190°. Clap-and-flings at dorsal and ventral stroke reversals were implemented to enhance vertical force. In the absence of a control surface at the tail, adjustment of the location of the trailing edges at the wing roots to modulate the rotational angle of the wings was used to generate control moments for the attitude control. Measurements by a 6-axis load cell showed that the control mechanism produced reasonable pitch, roll and yaw moments according to the corresponding control inputs. The control mechanism was integrated with three sub-micro servos to realize the pitch, roll and yaw controls. A simple PD feedback controller was implemented for flight stability with an onboard microcontroller and a gyroscope that sensed the pitch, roll and yaw rates. Several flight tests demonstrated that the tailless KUBeetle could successfully perform a vertical climb, then hover and loiter within a 0.3 m ground radius with small variations in pitch and roll body angles.

  6. VSTOL Systems Research Aircraft (VSRA) Harrier

    NASA Technical Reports Server (NTRS)

    1994-01-01

    NASA's Ames Research Center has developed and is testing a new integrated flight and propulsion control system that will help pilots land aircraft in adverse weather conditions and in small confined ares (such as, on a small ship or flight deck). The system is being tested in the V/STOL (Vertical/Short Takeoff and Landing) Systems research Aircraft (VSRA), which is a modified version of the U.S. Marine Corps's AV-8B Harrier jet fighter, which can take off and land vertically. The new automated flight control system features both head-up and panel-mounted computer displays and also automatically integrates control of the aircraft's thrust and thrust vector control, thereby reducing the pilot's workload and help stabilize the aircraft for landing. Visiting pilots will be encouraged to test the new system and provide formal evaluation flights data and feedback. An actual flight test and the display panel of control system are shown in this video.

  7. Artificial Intelligence Based Control Power Optimization on Tailless Aircraft. [ARMD Seedling Fund Phase I

    NASA Technical Reports Server (NTRS)

    Gern, Frank; Vicroy, Dan D.; Mulani, Sameer B.; Chhabra, Rupanshi; Kapania, Rakesh K.; Schetz, Joseph A.; Brown, Derrell; Princen, Norman H.

    2014-01-01

    Traditional methods of control allocation optimization have shown difficulties in exploiting the full potential of controlling large arrays of control devices on innovative air vehicles. Artificial neutral networks are inspired by biological nervous systems and neurocomputing has successfully been applied to a variety of complex optimization problems. This project investigates the potential of applying neurocomputing to the control allocation optimization problem of Hybrid Wing Body (HWB) aircraft concepts to minimize control power, hinge moments, and actuator forces, while keeping system weights within acceptable limits. The main objective of this project is to develop a proof-of-concept process suitable to demonstrate the potential of using neurocomputing for optimizing actuation power for aircraft featuring multiple independently actuated control surfaces. A Nastran aeroservoelastic finite element model is used to generate a learning database of hinge moment and actuation power characteristics for an array of flight conditions and control surface deflections. An artificial neural network incorporating a genetic algorithm then uses this training data to perform control allocation optimization for the investigated aircraft configuration. The phase I project showed that optimization results for the sum of required hinge moments are improved by more than 12% over the best Nastran solution by using the neural network optimization process.

  8. Numerical Aircraft Design Using 3-D Transonic Analysis with Optimization. Volume I. Executive Summary.

    DTIC Science & Technology

    1981-08-01

    spanl]der designs with thick wings, and winglets for transport-category aircraft; and, (2) swept forward wings, variable camber wings with direct...lift control, canards, and blended -wing concepts for fighters. Because efficient transonic performance continues to be an important design requirement

  9. Pursuit of the Torch: Influences on Acquisition of USAAF Fighter Aircraft Used in the North African Campaign

    DTIC Science & Technology

    2010-06-01

    138- 143 . 36 advancing bomber versus pursuit technology took on greater significance. The need to establish a balanced force was just one more...54 Watson, 138- 143 . 55 AAF Statistical Digest: World War II, December 1945, Table 79. The percentage...72 William Wolf American Fighter-Bombers in World War II: USAAF Jabos in the MTO and ETO (Atglen, PA: Schiffer

  10. The design of a wind tunnel VSTOL fighter model incorporating turbine powered engine simulators

    NASA Technical Reports Server (NTRS)

    Bailey, R. O.; Maraz, M. R.; Hiley, P. E.

    1981-01-01

    A wind-tunnel model of a supersonic VSTOL fighter aircraft configuration has been developed for use in the evaluation of airframe-propulsion system aerodynamic interactions. The model may be employed with conventional test techniques, where configuration aerodynamics are measured in a flow-through mode and incremental nozzle-airframe interactions are measured in a jet-effects mode, and with the Compact Multimission Aircraft Propulsion Simulator which is capable of the simultaneous simulation of inlet and exhaust nozzle flow fields so as to allow the evaluation of the extent of inlet and nozzle flow field coupling. The basic configuration of the twin-engine model has a geometrically close-coupled canard and wing, and a moderately short nacelle with nonaxisymmetric vectorable exhaust nozzles near the wing trailing edge, and may be converted to a canardless configuration with an extremely short nacelle. Testing is planned to begin in the summer of 1982.

  11. Comparison of wind tunnel and flight test afterbody and nozzle pressures for a twin-jet fighter aircraft at transonic speeds

    NASA Technical Reports Server (NTRS)

    Nugent, Jack; Pendergraft, Odis C., Jr.

    1987-01-01

    Afterbody and nozzle pressures measured on a 1/12-scale model and in flight on a twin-jet fighter aircraft were compared as Mach number varied from 0.6 to 1.2, Reynolds number from 17.5 million to 302.5 million, and angle of attack from 1 to 7 deg. At Mach 0.6 and 0.8, nozzle pressure coefficient distributions and nozzle axial force coefficients agreed and showed good recompression. At Mach 0.9 and 1.2, flow complexity caused a loss in recompression for both flight and wind tunnel nozzle data. The flight data exhibited less negative values of pressure coefficient and lower axial force coefficients than did the wind tunnel data. Reynolds number effects were noted only at these Mach numbers. Jet temperature and mass flux ratio did not affect the comparisons of nozzle axial flow coefficient. At subsonic speeds, the levels of pressure coefficient distributions on the upper fuselage and lower nacelle surfaces for flight were less negative than those for the model. The model boundary layer thickness at the aft rake station exceeded that for the forward rake station and increased with increasing angle of attack. The flight boundary layer thickness at the aft rake station was less than that for the forward rake station and decreased with increasing angle of attack.

  12. Application of dynamical systems theory to nonlinear aircraft dynamics

    NASA Technical Reports Server (NTRS)

    Culick, Fred E. C.; Jahnke, Craig C.

    1988-01-01

    Dynamical systems theory has been used to study nonlinear aircraft dynamics. A six degree of freedom model that neglects gravity has been analyzed. The aerodynamic model, supplied by NASA, is for a generic swept wing fighter and includes nonlinearities as functions of the angle of attack. A continuation method was used to calculate the steady states of the aircraft, and bifurcations of these steady states, as functions of the control deflections. Bifurcations were used to predict jump phenomena and the onset of periodic motion for roll coupling instabilities and high angle of attack maneuvers. The predictions were verified with numerical simulations.

  13. Aircraft geometry verification with enhanced computer generated displays

    NASA Technical Reports Server (NTRS)

    Cozzolongo, J. V.

    1982-01-01

    A method for visual verification of aerodynamic geometries using computer generated, color shaded images is described. The mathematical models representing aircraft geometries are created for use in theoretical aerodynamic analyses and in computer aided manufacturing. The aerodynamic shapes are defined using parametric bi-cubic splined patches. This mathematical representation is then used as input to an algorithm that generates a color shaded image of the geometry. A discussion of the techniques used in the mathematical representation of the geometry and in the rendering of the color shaded display is presented. The results include examples of color shaded displays, which are contrasted with wire frame type displays. The examples also show the use of mapped surface pressures in terms of color shaded images of V/STOL fighter/attack aircraft and advanced turboprop aircraft.

  14. Numerical Stability and Control Analysis Towards Falling-Leaf Prediction Capabilities of Splitflow for Two Generic High-Performance Aircraft Models

    NASA Technical Reports Server (NTRS)

    Charlton, Eric F.

    1998-01-01

    Aerodynamic analysis are performed using the Lockheed-Martin Tactical Aircraft Systems (LMTAS) Splitflow computational fluid dynamics code to investigate the computational prediction capabilities for vortex-dominated flow fields of two different tailless aircraft models at large angles of attack and sideslip. These computations are performed with the goal of providing useful stability and control data to designers of high performance aircraft. Appropriate metrics for accuracy, time, and ease of use are determined in consultations with both the LMTAS Advanced Design and Stability and Control groups. Results are obtained and compared to wind-tunnel data for all six components of forces and moments. Moment data is combined to form a "falling leaf" stability analysis. Finally, a handful of viscous simulations were also performed to further investigate nonlinearities and possible viscous effects in the differences between the accumulated inviscid computational and experimental data.

  15. An engine trade study for a supersonic STOVL fighter-attack aircraft, volume 1

    NASA Technical Reports Server (NTRS)

    Beard, B. B.; Foley, W. H.

    1982-01-01

    The best main engine for an advanced STOVL aircraft flight demonstrator was studied. The STOVL aircraft uses ejectors powered by engine bypass flow together with vectored core exhaust to achieve vertical thrust capability. Bypass flow and core flow are exhausted through separate nozzles during wingborne flight. Six near term turbofan engines were examined for suitability for this aircraft concept. Fan pressure ratio, thrust split between bypass and core flow, and total thrust level were used to compare engines. One of the six candidate engines was selected for the flight demonstrator configuration. Propulsion related to this aircraft concept was studied. A preliminary candidate for the aircraft reaction control system for hover attitude control was selected. A mathematical model of transfer of bypass thrust from ejectors to aft directed nozzle during the transition to wingborne flight was developed. An equation to predict ejector secondary air flow rate and ram drag is derived. Additional topics discussed include: nozzle area control, ejector to engine inlet reingestion, bypass/core thrust split variation, and gyroscopic behavior during hover.

  16. Investigation of Stability and Control Characteristics of a 1/10-scale Model of a Canadian Tailless Glider in the Langley Free-flight Tunnel

    NASA Technical Reports Server (NTRS)

    Johnson, Joseph L.

    1949-01-01

    An investigation of the stability and control characteristics of a 1/10-scale model of a Canadian tailless glider has been conducted in the 10 Langley free-flight tunnel. The glider designated the N.R.L. tailless glider has a straight center section and outboard panels sweptback 43 deg. along the leading edge of the wing. The aspect ratio is 5.83 and the taper ratio is 0.323. From the results of the investigation and on the basis of comparison with higher-scale static tests of the National Research Council of Canada, it is expected that the longitudinal stability of the airplane will be satisfactory with flap up but unsatisfactory near the stall with flap down. The airplane is expected to have unsatisfactory lateral stability and control characteristics in the design configuration with either flap up or flap down. The model flights showed very low damping of the lateral oscillation. Increasing the vertical-tail area improved the lateral stability, and it appeared that a value of the directional-stability parameter C(sub n beta) of at least 0.002 per degree would probably be necessary for satisfactory lateral flying characteristics. A comparison of the calculated dynamic lateral stability characteristics of the N.R.L. tailless glider with those of a conventional-type sweptback airplane having a similar wing plan form and about the same inclination of the principal longitudinal axis of inertia showed that the tailless glider had poorer lateral stability because of the relatively larger radius of gyration in roll and the smaller damping-in-yaw factor C(sub nr).

  17. Similar Intracellular Location and Stimulus Reactivity, but Differential Mobility of Tailless (Vicia faba) and Tailed Forisomes (Phaseolus vulgaris) in Intact Sieve Tubes.

    PubMed

    Furch, Alexandra C U; Buxa, Stefanie V; van Bel, Aart J E

    2015-01-01

    Sieve elements of legumes contain forisomes-fusiform protein bodies that are responsible for sieve-tube occlusion in response to damage or wound signals. Earlier work described the existence of tailless and tailed forisomes. This study intended to quantify and compare location and position of tailless (in Vicia faba) and tailed (in Phaseolus vulgaris) forisomes inside sieve elements and to assess their reactivity and potential mobility in response to a remote stimulus. Location (distribution within sieve elements) and position (forisome tip contacts) of more than altogether 2000 forisomes were screened in 500 intact plants by laser scanning confocal microscopy in the transmission mode. Furthermore, we studied the dispersion of forisomes at different locations in different positions and their positional behaviour in response to distant heat shocks. Forisome distribution turned out to be species-specific, whereas forisome positions at various locations were largely similar in bushbean (Phaseolus) and broadbean (Vicia). In general, the tailless forisomes had higher dispersion rates in response to heat shocks than the tailed forisomes and forisomes at the downstream (basal) end dispersed more frequently than those at the upstream end (apical). In contrast to the tailless forisomes that only oscillate in response to heat shocks, downstream-located tailed forisomes can cover considerable distances within sieve elements. This displacement was prevented by gentle rubbing of the leaf (priming) before the heat shock. Movement of these forisomes was also prohibited by Latrunculin A, an inhibitor of actin polymerization. The apparently active mobility of tailed forisomes gives credence to the idea that at least the latter forisomes are not free-floating, but connected to other sieve-element structures.

  18. Similar Intracellular Location and Stimulus Reactivity, but Differential Mobility of Tailless (Vicia faba) and Tailed Forisomes (Phaseolus vulgaris) in Intact Sieve Tubes

    PubMed Central

    van Bel, Aart J. E.

    2015-01-01

    Sieve elements of legumes contain forisomes—fusiform protein bodies that are responsible for sieve-tube occlusion in response to damage or wound signals. Earlier work described the existence of tailless and tailed forisomes. This study intended to quantify and compare location and position of tailless (in Vicia faba) and tailed (in Phaseolus vulgaris) forisomes inside sieve elements and to assess their reactivity and potential mobility in response to a remote stimulus. Location (distribution within sieve elements) and position (forisome tip contacts) of more than altogether 2000 forisomes were screened in 500 intact plants by laser scanning confocal microscopy in the transmission mode. Furthermore, we studied the dispersion of forisomes at different locations in different positions and their positional behaviour in response to distant heat shocks. Forisome distribution turned out to be species-specific, whereas forisome positions at various locations were largely similar in bushbean (Phaseolus) and broadbean (Vicia). In general, the tailless forisomes had higher dispersion rates in response to heat shocks than the tailed forisomes and forisomes at the downstream (basal) end dispersed more frequently than those at the upstream end (apical). In contrast to the tailless forisomes that only oscillate in response to heat shocks, downstream-located tailed forisomes can cover considerable distances within sieve elements. This displacement was prevented by gentle rubbing of the leaf (priming) before the heat shock. Movement of these forisomes was also prohibited by Latrunculin A, an inhibitor of actin polymerization. The apparently active mobility of tailed forisomes gives credence to the idea that at least the latter forisomes are not free-floating, but connected to other sieve-element structures. PMID:26624625

  19. Aircraft stress sequence development: A complex engineering process made simple

    NASA Technical Reports Server (NTRS)

    Schrader, K. H.; Butts, D. G.; Sparks, W. A.

    1994-01-01

    Development of stress sequences for critical aircraft structure requires flight measured usage data, known aircraft loads, and established relationships between aircraft flight loads and structural stresses. Resulting cycle-by-cycle stress sequences can be directly usable for crack growth analysis and coupon spectra tests. Often, an expert in loads and spectra development manipulates the usage data into a typical sequence of representative flight conditions for which loads and stresses are calculated. For a fighter/trainer type aircraft, this effort is repeated many times for each of the fatigue critical locations (FCL) resulting in expenditure of numerous engineering hours. The Aircraft Stress Sequence Computer Program (ACSTRSEQ), developed by Southwest Research Institute under contract to San Antonio Air Logistics Center, presents a unique approach for making complex technical computations in a simple, easy to use method. The program is written in Microsoft Visual Basic for the Microsoft Windows environment.

  20. Computational Fluid Dynamics Analysis Success Stories of X-Plane Design to Flight Test

    NASA Technical Reports Server (NTRS)

    Cosentino, Gary B.

    2008-01-01

    Examples of the design and flight test of three true X-planes are described, particularly X-plane design techniques that relied heavily on computational fluid dynamics(CFD) analysis. Three examples are presented: the X-36 Tailless Fighter Agility Research Aircraft, the X-45A Unmanned Combat Air Vehicle, and the X-48B Blended Wing Body Demonstrator Aircraft. An overview is presented of the uses of CFD analysis, comparison and contrast with wind tunnel testing, and information derived from CFD analysis that directly related to successful flight test. Lessons learned on the proper and improper application of CFD analysis are presented. Highlights of the flight-test results of the three example X-planes are presented. This report discusses developing an aircraft shape from early concept and three-dimensional modeling through CFD analysis, wind tunnel testing, further refined CFD analysis, and, finally, flight. An overview of the areas in which CFD analysis does and does not perform well during this process is presented. How wind tunnel testing complements, calibrates, and verifies CFD analysis is discussed. Lessons learned revealing circumstances under which CFD analysis results can be misleading are given. Strengths and weaknesses of the various flow solvers, including panel methods, Euler, and Navier-Stokes techniques, are discussed.

  1. Modified Dynamic Inversion to Control Large Flexible Aircraft: What's Going On?

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.

    1999-01-01

    High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper explores dynamic inversion application to an advanced highly flexible aircraft. An initial application has been made to a large flexible supersonic aircraft. In the course of controller design for this advanced vehicle, modifications were made to the standard dynamic inversion methodology. The results of this application were deemed rather promising. An analytical study has been undertaken to better understand the nature of the made modifications and to determine its general applicability. This paper presents the results of this initial analytical look at the modifications to dynamic inversion to control large flexible aircraft.

  2. Fighting Testing ACAT/FRRP: Automatic Collision Avoidance Technology/Fighter Risk Reduction Project

    NASA Technical Reports Server (NTRS)

    Skoog, Mark A.

    2009-01-01

    This slide presentation reviews the work of the Flight testing Automatic Collision Avoidance Technology/Fighter Risk Reduction Project (ACAT/FRRP). The goal of this project is to develop common modular architecture for all aircraft, and to enable the transition of technology from research to production as soon as possible to begin to reduce the rate of mishaps. The automated Ground Collision Avoidance System (GCAS) system is designed to prevent collision with the ground, by avionics that project the future trajectory over digital terrain, and request an evasion maneuver at the last instance. The flight controls are capable of automatically performing a recovery. The collision avoidance is described in the presentation. Also included in the presentation is a description of the flight test.

  3. Aircraft Airframe Cost Estimation Using a Random Coefficients Model

    DTIC Science & Technology

    1979-12-01

    approach will also be used here. 2 Model Formulation Several different types of equations could be used for the basic form of the CER, such as linear ...5) Marcotte developed several CER’s for fighter aircraft airframes using the log- linear model . A plot of the residuals from the CER for recurring...of the natural logarithm. Ordinary Least Squares The ordinary least squares procedure starts with the equation for the general linear model . The

  4. Elliptic generation of composite three-dimensional grids about realistic aircraft

    NASA Technical Reports Server (NTRS)

    Sorenson, R. L.

    1986-01-01

    An elliptic method for generating composite grids about realistic aircraft is presented. A body-conforming grid is first generated about the entire aircraft by the solution of Poisson's differential equation. This grid has relatively coarse spacing, and it covers the entire physical domain. At boundary surfaces, cell size is controlled and cell skewness is nearly eliminated by inhomogeneous terms, which are found automatically by the program. Certain regions of the grid in which high gradients are expected, and which map into rectangular solids in the computational domain, are then designated for zonal refinement. Spacing in the zonal grids is reduced by adding points with a simple, algebraic scheme. Details of the grid generation method are presented along with results of the present application, a wing-body configuration based on the F-16 fighter aircraft.

  5. Longitudinal performance of plasma neurofilament light and tau in professional fighters: The Professional Fighters Brain Health Study.

    PubMed

    Bernick, Charles; Zetterberg, Henrik; Shan, Guogen; Banks, Sarah; Blennow, Kaj

    2018-04-02

    The objective of this study is to evaluate longitudinal change in plasma neurofilament light (NF-L) and tau levels in relationship to clinical and radiological measures in professional fighters. Participants (active and retired professional fighters and control group) underwent annual blood sampling, 3 Tesla MRI brain imaging, computerized cognitive testing, and assessment of exposure to head trauma. Plasma tau and NF-L concentrations were measured using Simoa assays. Multiple linear regression models were used to compare the difference across groups in regard to baseline measurements, while mixed linear models was used for the longitudinal data with multiple measurements for each participant. Plasma samples were available on 471 participants. Baseline NF-L measures differed across groups (F_3,393=6.99, p=0.0001), with the active boxers having the highest levels. Higher NF-L levels at baseline were correlated with lower baseline MRI regional volumes and lower cognitive scores. The number of sparring rounds completed by the active fighters was correlated with NF-L (95% CI 0.0116-0.4053, p=0.0381), but not tau, levels. Among 126 subjects having multiple yearly samples, there was a significant difference in average yearly percentage change in tau across groups (F_3,83=3.87, p=0.0121).). We conclude that plasma NF-L and tau behave differently in a group of active and retired fighters; NF-L better reflects acute exposure whereas the role of plasma tau levels in signifying chronic change in brain structure over time requires further study.

  6. Optimization of nas lemoore scheduling to support a growing aircraft population

    DTIC Science & Technology

    2017-03-01

    requirements, and, without knowing the other squadrons’ flight plans , creates his or her squadron’s flight schedule. Figure 2 illustrates the process each...Lemoore, they do not communicate their flight schedules among themselves; hence, the daily flight plan generated by each squadron is independently...manual process for aircraft flight scheduling at Naval Air Station (NAS) Lemoore accommodates the independent needs of 16 fighter resident squadrons as

  7. Human and behavioral factors contributing to spine-based neurological cockpit injuries in pilots of high-performance aircraft: recommendations for management and prevention

    NASA Technical Reports Server (NTRS)

    Jones, J. A.; Hart, S. F.; Baskin, D. S.; Effenhauser, R.; Johnson, S. L.; Novas, M. A.; Jennings, R.; Davis, J.

    2000-01-01

    In high-performance aircraft, the need for total environmental awareness coupled with high-g loading (often with abrupt onset) creates a predilection for cervical spine injury while the pilot is performing routine movements within the cockpit. In this study, the prevalence and severity of cervical spine injury are assessed via a modified cross-sectional survey of pilots of multiple aircraft types (T-38 and F-14, F-16, and F/A-18 fighters). Ninety-five surveys were administered, with 58 full responses. Fifty percent of all pilots reported in-flight or immediate post-flight spine-based pain, and 90% of fighter pilots reported at least one event, most commonly (> 90%) occurring during high-g (> 5 g) turns of the aircraft with the head deviated from the anatomical neutral position. Pre-flight stretching was not associated with a statistically significant reduction in neck pain episodes in this evaluation, whereas a regular weight training program in the F/A-18 group approached a significant reduction (mean = 2.492; p < 0.064). Different cockpit ergonomics may vary the predisposition to cervical injury from airframe to airframe. Several strategies for prevention are possible from both an aircraft design and a preventive medicine standpoint. Countermeasure strategies against spine injury in pilots of high-performance aircraft require additional research, so that future aircraft will not be limited by the human in control.

  8. Psychological distress and alcohol use among fire fighters.

    PubMed

    Boxer, P A; Wild, D

    1993-04-01

    Few studies have investigated stressors to which fire fighters are subjected and the potential psychological consequences. One hundred and forty-five fire fighters were studied to enumerate potential occupational stressors, assess psychological distress and problems with alcohol use, and determine whether a relationship exists between these measures and self-reported stressors. Hearing that children are in a burning building was the highest ranked stressor. According to three self-report instruments, between 33 and 41% of the fire fighters were experiencing significant psychological distress, and 29% had possible or probable problems with alcohol use. These figures are significantly higher than would be expected in a typical community or working population. In a logistic regression analysis, no relationship was found between measures of psychological distress and alcohol use and the 10 most highly ranked work stressors.

  9. Dehydration and acute weight gain in mixed martial arts fighters before competition.

    PubMed

    Jetton, Adam M; Lawrence, Marcus M; Meucci, Marco; Haines, Tracie L; Collier, Scott R; Morris, David M; Utter, Alan C

    2013-05-01

    The purpose of this study was to characterize the magnitude of acute weight gain (AWG) and dehydration in mixed martial arts (MMA) fighters before competition. Urinary measures of hydration status and body mass were determined approximately 24 hours before and then again approximately 2 hours before competition in 40 MMA fighters (mean ± SE, age: 25.2 ± 0.65 years, height: 1.77 ± 0.01 m, body mass: 75.8 ± 1.5 kg). The AWG was defined as the amount of body weight the fighters gained in the approximately 22-hour period between the official weigh-in and the actual competition. On average, the MMA fighters gained 3.40 ± 2.2 kg or 4.4% of their body weight in the approximately 22-hour period before competition. Urine specific gravity significantly decreased (p < 0.001) from 1.028 ± 0.001 to 1.020 ± 0.001 during the approximately 22-hour rehydration period. Results demonstrated that 39% of the MMA fighters presented with a Usg of >1.021 immediately before competition indicating significant or serious dehydration. The MMA fighters undergo significant dehydration and fluctuations in body mass (4.4% avg.) in the 24-hour period before competition. Urinary measures of hydration status indicate that a significant proportion of MMA fighters are not successfully rehydrating before competition and subsequently are competing in a dehydrated state. Weight management guidelines to prevent acute dehydration in MMA fighters are warranted to prevent unnecessary adverse health events secondary to dehydration.

  10. Design study of test models of maneuvering aircraft configurations for the National Transonic Facility (NTF)

    NASA Technical Reports Server (NTRS)

    Griffin, S. A.; Madsen, A. P.; Mcclain, A. A.

    1984-01-01

    The feasibility of designing advanced technology, highly maneuverable, fighter aircraft models to achieve full scale Reynolds number in the National Transonic Facility (NTF) is examined. Each of the selected configurations are tested for aeroelastic effects through the use of force and pressure data. A review of materials and material processes is also included.

  11. 78 FR 33357 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ...) Program. Multiple munitions (bombs, missiles, and gunner rounds) and aircraft would be used to meet the... with Munitions specific munitions) GBU-10 laser-guided Mk-84 bomb F-16C fighter aircraft. GBU-24 laser-guided Mk-84 bomb F-16C+ fighter aircraft. GBU-31 Joint Direct Attack Munition, F-15E fighter aircraft...

  12. Computational Fluid Dynamics of Whole-Body Aircraft

    NASA Astrophysics Data System (ADS)

    Agarwal, Ramesh

    1999-01-01

    The current state of the art in computational aerodynamics for whole-body aircraft flowfield simulations is described. Recent advances in geometry modeling, surface and volume grid generation, and flow simulation algorithms have led to accurate flowfield predictions for increasingly complex and realistic configurations. As a result, computational aerodynamics has emerged as a crucial enabling technology for the design and development of flight vehicles. Examples illustrating the current capability for the prediction of transport and fighter aircraft flowfields are presented. Unfortunately, accurate modeling of turbulence remains a major difficulty in the analysis of viscosity-dominated flows. In the future, inverse design methods, multidisciplinary design optimization methods, artificial intelligence technology, and massively parallel computer technology will be incorporated into computational aerodynamics, opening up greater opportunities for improved product design at substantially reduced costs.

  13. Low-speed wind-tunnel investigation of a porous forebody and nose strakes for yaw control of a multirole fighter aircraft

    NASA Technical Reports Server (NTRS)

    Fears, Scott P.

    1995-01-01

    Low-speed wind-tunnel tests were conducted in the Langley 12-Foot Low-Speed Tunnel on a model of the Boeing Multirole Fighter (BMRF) aircraft. This single-seat, single-engine configuration was intended to be an F-16 replacement that would incorporate many of the design goals and advanced technologies of the F-22. Its mission requirements included supersonic cruise without afterburner, reduced observability, and the ability to attack both air-to-air and air-to-ground targets. So that it would be effective in all phases of air combat, the ability to maneuver at angles of attack up to and beyond maximum lift was also desired. Traditional aerodynamic yaw controls, such as rudders, are typically ineffective at these higher angles of attack because they are usually located in the wake from the wings and fuselage. For this reason, this study focused on investigating forebody-mounted controls that produces yawing moments by modifying the strong vortex flowfield being shed from the forebody at high angles of attack. Two forebody strakes were tested that varied in planform and chordwise location. Various patterns of porosity in the forebody skin were also tested that differed in their radial coverage and chordwise location. The tests were performed at a dynamic pressure of 4 lb/ft(exp 2) over an angle-of-attack range of -4 deg to 72 deg and a sideslip range of -10 deg to 10 deg. Static force data, static pressures on the surface of the forebody, and videotapes of flow-visualization using laser-illuminated smoke were obtained.

  14. Workshop on Design Loads for Advanced Fighters: Meeting of the Structures and Materials Panel of AGARD (64th) Held in Madrid (Spain) on 27 April-1 May 1987.

    DTIC Science & Technology

    1988-02-01

    capabilities at the start of a programme. ,Z _ 1. Introduction The flight manoeuvre loads are major design criteria for agile aircraft (aerobatic...E. Van Patten, Ph.D. Armstrong Aerospace Medical Research Laboratory Wright-Patterson AFB, OH 45433-6573 USA INTRODUCTION ~ urrent Fighter...anticipated usage. Also, compliance with each condition mit he verified by analysis, model test, or full scale measurement. INTRODUCTION During the

  15. Professional fighters brain health study: rationale and methods.

    PubMed

    Bernick, Charles; Banks, Sarah; Phillips, Michael; Lowe, Mark; Shin, Wanyong; Obuchowski, Nancy; Jones, Stephen; Modic, Michael

    2013-07-15

    Repetitive head trauma is a risk factor for Alzheimer's disease and is the primary cause of chronic traumatic encephalopathy. However, little is known about the natural history of, and risk factors for, chronic traumatic encephalopathy or about means of early detection and intervention. The Professional Fighters Brain Health Study is a longitudinal study of active professional fighters (boxers and mixed martial artists), retired professional fighters, and controls matched for age and level of education. The main objective of the Professional Fighters Brain Health Study is to determine the relationships between measures of head trauma exposure and other potential modifiers and changes in brain imaging and neurological and behavioral function over time. The study is designed to extend over 5 years, and we anticipate enrollment of more than 400 boxers and mixed martial artists. Participants will undergo annual evaluations that include 3-tesla magnetic resonance imaging scanning, computerized cognitive assessments, speech analysis, surveys of mood and impulsivity, and blood sampling for genotyping and exploratory biomarker studies. Statistical models will be developed and validated to predict early and progressive changes in brain structure and function. A composite fight exposure index, developed as a summary measure of cumulative traumatic exposure, shows promise as a predictor of brain volumes and cognitive function.

  16. Aerodynamic characteristics of a large-scale lift-engine fighter model with external swiveling lift-engines

    NASA Technical Reports Server (NTRS)

    Barrack, J. P.; Kirk, J. V.

    1972-01-01

    The aerodynamic characteristics of a six-engine (four lift, two lift-cruise) lift-engine model obtained in the Ames 40- by 80-foot wind tunnel are presented. The model was an approximate one-half scale representation of a lift-engine VTOL fighter aircraft with a variable-sweep wing. The four lift-engines were housed in the aft fuselage with the inlets located above the wing. Longitudinal and lateral-directional force and moment data are presented for a range of exhaust gas momentum ratios (thrust coefficients). Wind tunnel forward speed was varied from 0 to 140 knots corresponding to a maximum Reynolds number of 6.7 million. The data are presented without analysis.

  17. Flight Reynolds number effects on a fighter-type, circular-arc-19 deg conic boattail nozzle at subsonic speeds

    NASA Technical Reports Server (NTRS)

    Chamberlin, R.

    1974-01-01

    A circular-arc - conic boattail nozzle, typical of those used on a twin engine fighter, was tested on an underwing nacelle mounted on an F-106B aircraft. The boattail had a radius ratio r/r sub c of 0.41 and a terminal boattail angle of approximately 19 deg. The gas generator was a J85-GE-13 turbojet engine. The effects of Reynolds number and angle of attack on boattail pressure drag and boattail pressure profiles were investigated. Increasing Reynolds number resulted in reduced boattail drag at both Mach numbers of 0.6 and 0.9.

  18. Escorting commercial aircraft to reduce the MANPAD threat

    NASA Astrophysics Data System (ADS)

    Hock, Nicholas; Richardson, M. A.; Butters, B.; Walmsley, R.; Ayling, R.; Taylor, B.

    2005-11-01

    This paper studies the Man-Portable Air Defence System (MANPADS) threat against large commercial aircraft using flight profile analysis, engagement modelling and simulation. Non-countermeasure equipped commercial aircraft are at risk during approach and departure due to the large areas around airports that would need to be secured to prevent the use of highly portable and concealable MANPADs. A software model (CounterSim) has been developed and was used to simulate an SA-7b and large commercial aircraft engagement. The results of this simulation have found that the threat was lessened when a escort fighter aircraft is flown in the 'Centreline Low' position, or 25 m rearward from the large aircraft and 15 m lower, similar to the Air-to-Air refuelling position. In the model a large aircraft on approach had a 50% chance of being hit or having a near miss (within 20m) whereas escorted by a countermeasure equipped F-16 in the 'Centerline Low' position, this was reduced to only 14%. Departure is a particularly vulnerable time for large aircraft due to slow climb rates and the inability to fly evasive manoeuvres. The 'Centreline Low' escorted departure greatly reduced the threat to 16% hit or near miss from 62% for an unescorted heavy aircraft. Overall the CounterSim modelling has showed that escorting a civilian aircraft on approach and departure can reduce the MANPAD threat by 3 to 4 times.

  19. Design and analysis of a supersonic penetration/maneuvering fighter

    NASA Technical Reports Server (NTRS)

    Child, R. D.

    1975-01-01

    The design of three candidate air combat fighters which would cruise effectively at freestream Mach numbers of 1.6, 2.0, and 2.5 while maintaining good transonic maneuvering capability, is considered. These fighters were designed to deliver aerodynamically controlled dogfight missiles at the design Mach numbers. Studies performed by Rockwell International in May 1974 and guidance from NASA determined the shape and size of these missiles. The principle objective of this study is the aerodynamic design of the vehicles; however, configurations are sized to have realistic structures, mass properties, and propulsion systems. The results of this study show that air combat fighters in the 15,000 to 23,000 pound class would cruise supersonically on dry power and still maintain good transonic maneuvering performance.

  20. Tactical Dispersal of Fighter Aircraft: Risk, Uncertainty, and Policy Recommendations.

    DTIC Science & Technology

    1987-02-01

    against armour and soft skinned vehicles, parked aircraft, and personnel, and are distributed evenly within the pattern... 147 bomblets are carried...initiated using such techniques as tone down paint schemes and camouflage netting. Active defenses have been enhanced. Patriot is replacing Nike , and...such as this. A0 vS I P l Il - 41 - V. ANALYSIS But we must ourselves take care not to acquire a Maginot dependence upon ground based static systems

  1. Investigation of trailing-edge-flap, spanwise-blowing concepts on an advanced fighter configuration

    NASA Technical Reports Server (NTRS)

    Paulson, J. W., Jr.; Quinto, P. F.; Banks, D. W.

    1984-01-01

    The aerodynamic effects of spanwise blowing on the trailing edge flap of an advanced fighter aircraft configuration were determined in the 4 by 7 Meter Tunnel. A series of tests were conducted with variations in spanwise-blowing vector angle, nozzle exit area, nozzle location, thrust coefficient, and flap deflection in order to determine a superior configuration for both an underwing cascade concept and an overwing port concept. This screening phase of the testing was conducted at a nominal approach angle of attack from 12 deg to 16 deg; and then the superior configurations were tested over a more complete angle of attack range from 0 deg to 20 deg at tunnel free stream dynamic pressures from 20 to 40 lbf/sq ft at thrust coefficients from 0 to 2.

  2. Which subgroups of fire fighters are more prone to work-related diminished health requirements?

    PubMed

    Plat, Marie-Christine J; Frings-Dresen, Monique H W; Sluiter, Judith K

    2012-10-01

    To determine whether certain subgroups of fire fighters are prone to work-related diminished health requirements. The health requirements for fire-fighting were tested in a workers' health surveillance (WHS) setting. These health requirements included psychological, physical and sense-related components as well as cardiovascular risk factors. The odds ratio (OR) and 95% confidence interval (95% CI) for the presence of the diminished health requirements were calculated for the subgroups of gender, professionalism and age. The prevalence of diminished psychological requirements was equivalent among the subgroups, and no significant high-risk group was identified. As compared to men fire fighters, women fire fighters were more likely to have diminished physical requirements (OR 28.5; 95% CI 12.1-66.9) and less likely to have cardiovascular risk factors (OR 0.3; 0.1-0.5). As compared to volunteer fire fighters, professionals were less likely to have diminished physical requirements (OR 0.5; 0.3-0.9), but professionals had a higher prevalence of cardiovascular risk factors with an odds ratio of 1.9 (1.1-3.2). As compared to the youngest fire fighters, the oldest fire fighters were more likely to have diminished sense-related requirements (OR 7.1; 3.4-15.2); a similar comparison could be made between oldest and middle-aged fire fighters (OR 5.1; 2.5-10.5). In addition, the oldest fire fighters were more likely to have cardiovascular risk factors when compared to the youngest (OR 4.4; 1.7-11.1) and to the middle-aged fire fighters (OR 3.1; 1.2-7.9). Subgroups (gender, professionalism and age) of fire fighters are prone to at least one specific work-related diminished health requirement. Therefore, parts of the WHS could be applied with more attention to these high-risk groups.

  3. An Evaluation of the Argentinean Basic Trainer Aircraft Domestic Development Project

    DTIC Science & Technology

    2012-03-01

    Prototype, 1st jet built in Latin America 1947 IAe 31 Colibrí Two- seat Trainer aircraft 3 National design 1948 IAe 30 Ñancú Fighter/Attack prototype...37 Supersonic delta-wing interceptor (Glider, unpowered prototype only) 1 Designed by Reimar Horten. 1957 IAe 46 Ranquel 2- seat utility...return all surfaces to neutral. It must be operable from both positions, with priority on the rear command seat . • Ergonomic Throttle controls on the

  4. A design procedure for the handling qualities optimization of the X-29A aircraft

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.; Cox, Timothy H.

    1989-01-01

    The techniques used to improve the pitch-axis handling qualities of the X-29A wing-canard-planform fighter aircraft are reviewed. The aircraft and its FCS are briefly described, and the design method, which works within the existing FCS architecture, is characterized in detail. Consideration is given to the selection of design goals and design variables, the definition and calculation of the cost function, the validation of the mathematical model on the basis of flight-test data, and the validation of the improved design by means of nonlinear simulations. Flight tests of the improved design are shown to verify the simulation results.

  5. An Investigation of Large Aircraft Handling Qualities

    NASA Astrophysics Data System (ADS)

    Joyce, Richard D.

    An analytical technique for investigating transport aircraft handling qualities is exercised in a study using models of two such vehicles, a Boeing 747 and Lockheed C-5A. Two flight conditions are employed for climb and directional tasks, and a third included for a flare task. The analysis technique is based upon a "structural model" of the human pilot developed by Hess. The associated analysis procedure has been discussed previously in the literature, but centered almost exclusively on the characteristics of high-performance fighter aircraft. The handling qualities rating level (HQRL) and pilot induced oscillation tendencies rating level (PIORL) are predicted for nominal configurations of the aircraft and for "damaged" configurations where actuator rate limits are introduced as nonlinearites. It is demonstrated that the analysis can accommodate nonlinear pilot/vehicle behavior and do so in the context of specific flight tasks, yielding estimates of handling qualities, pilot-induced oscillation tendencies and upper limits of task performance. A brief human-in-the-loop tracking study was performed to provide a limited validation of the pilot model employed.

  6. 78 FR 52135 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-22

    ... Tactics Development and Evaluation (TD&E) Program. Multiple munitions (bombs, missiles, and gunner rounds... laser-guided Mk-84 bomb F-16C fighter aircraft. GBU-24 laser-guided Mk-84 bomb F-16C+ fighter aircraft... bomb. GBU-12 laser-guided Mk-82 bomb A-10 fighter aircraft. GBU-38 Joint Direct Attack Munition, global...

  7. In-flight lift-drag characteristics for a forward-swept wing aircraft and comparisons with contemporary aircraft)

    NASA Technical Reports Server (NTRS)

    Saltzman, Edwin J.; Hicks, John W.; Luke, Sue (Editor)

    1994-01-01

    Lift (L) and drag (D) characteristics have been obtained in flight for the X-29A airplane (a forward swept-wing demonstrator) for Mach numbers (M) from 0.4 to 1.3. Most of the data were obtained near an altitude of 30,000 ft. A representative Reynolds number for M = 0.9, and a pressure altitude of 30,000 ft, is 18.6 x 10(exp 6) based on the mean aerodynamic chord. The X-29A data (forward-swept wing) are compared with three high-performance fighter aircraft: the F-15C, F-16C, and F/A18. The lifting efficiency of the X-29A, as defined by the Oswald lifting efficiency factor, e, is about average for a cantilevered monoplane for M = 0.6 and angles of attack up to those required for maximum L/D. At M = 0.6 the level of L/D and e, as a function of load factor, for the X-29A was about the same as for the contemporary aircraft. The X-29A and its contemporaries have high transonic wave drag and equivalent parasite area compared with aircraft of the 1940's through 1960's.

  8. Program Fighter - An Evaluation.

    ERIC Educational Resources Information Center

    Hull, David G.; Fowler, Wallace T.

    Described is a computer program for the sizing of subsonic and supersonic fighters which has been adapted for use in an aerospace engineering design course. Following a description of the program, an evaluation of its use in the university is presented. It is concluded that computer programs for the conceptual design of aerospace vehicles can play…

  9. A computer technique for detailed analysis of mission radius and maneuverability characteristics of fighter aircraft

    NASA Technical Reports Server (NTRS)

    Foss, W. E., Jr.

    1981-01-01

    A computer technique to determine the mission radius and maneuverability characteristics of combat aircraft was developed. The technique was used to determine critical operational requirements and the areas in which research programs would be expected to yield the most beneficial results. In turn, the results of research efforts were evaluated in terms of aircraft performance on selected mission segments and for complete mission profiles. Extensive use of the technique in evaluation studies indicates that the calculated performance is essentially the same as that obtained by the proprietary programs in use throughout the aircraft industry.

  10. Damage tolerance certification of a fighter horizontal stabilizer

    NASA Astrophysics Data System (ADS)

    Huang, Jia-Yen; Tsai, Ming-Yang; Chen, Jong-Sheng; Ong, Ching-Long

    1995-05-01

    A review of the program for the damage tolerance certification test of a composite horizontal stabilizer (HS) of a fighter is presented. The object of this program is to certify that the fatigue life and damage tolerance strength of a damaged composite horizontal stabilizer meets the design requirements. According to the specification for damage tolerance certification, a test article should be subjected to two design lifetimes of flight-by-flight load spectra simulating the in-service fatigue loading condition for the aircraft. However, considering the effect of environmental change on the composite structure, one additional lifetime test was performed. In addition, to evaluate the possibilities for extending the service life of the structure, one more lifetime test was carried out with the spectrum increased by a factor of 1.4. To assess the feasibility and reliability of repair technology on a composite structure, two damaged areas were repaired after two lifetimes of damage tolerance test. On completion of four lifetimes of the damage tolerance test, the static residual strength was measured to check whether structural strength after repair met the requirements. Stiffness and static strength of the composite HS with and without damage were evaluated and compared.

  11. A Study on Aircraft Engine Control Systems for Integrated Flight and Propulsion Control

    NASA Astrophysics Data System (ADS)

    Yamane, Hideaki; Matsunaga, Yasushi; Kusakawa, Takeshi; Yasui, Hisako

    The Integrated Flight and Propulsion Control (IFPC) for a highly maneuverable aircraft and a fighter-class engine with pitch/yaw thrust vectoring is described. Of the two IFPC functions the aircraft maneuver control utilizes the thrust vectoring based on aerodynamic control surfaces/thrust vectoring control allocation specified by the Integrated Control Unit (ICU) of a FADEC (Full Authority Digital Electronic Control) system. On the other hand in the Performance Seeking Control (PSC) the ICU identifies engine's various characteristic changes, optimizes manipulated variables and finally adjusts engine control parameters in cooperation with the Engine Control Unit (ECU). It is shown by hardware-in-the-loop simulation that the thrust vectoring can enhance aircraft maneuverability/agility and that the PSC can improve engine performance parameters such as SFC (specific fuel consumption), thrust and gas temperature.

  12. Calculated performance, stability and maneuverability of high-speed tilting-prop-rotor aircraft

    NASA Technical Reports Server (NTRS)

    Johnson, Wayne; Lau, Benton H.; Bowles, Jeffrey V.

    1986-01-01

    The feasibility of operating tilting-prop-rotor aircraft at high speeds is examined by calculating the performance, stability, and maneuverability of representative configurations. The rotor performance is examined in high-speed cruise and in hover. The whirl-flutter stability of the coupled-wing and rotor motion is calculated in the cruise mode. Maneuverability is examined in terms of the rotor-thrust limit during turns in helicopter configuration. Rotor airfoils, rotor-hub configuration, wing airfoil, and airframe structural weights representing demonstrated advance technology are discussed. Key rotor and airframe parameters are optimized for high-speed performance and stability. The basic aircraft-design parameters are optimized for minimum gross weight. To provide a focus for the calculations, two high-speed tilt-rotor aircraft are considered: a 46-passenger, civil transport and an air-combat/escort fighter, both with design speeds of about 400 knots. It is concluded that such high-speed tilt-rotor aircraft are quite practical.

  13. Piloted simulator evaluation of a relaxed static stability fighter at high angle-of-attack

    NASA Technical Reports Server (NTRS)

    Lapins, M.; Klein, R. W.; Martorella, R. P.; Cangelosi, J.; Neely, W. R., Jr.

    1982-01-01

    A piloted simulator evaluation of the stability and control characteristics of a relaxed static stability fighter aircraft was conducted using a differential maneuvering simulator. The primary purpose of the simulation was to evaluate the effectiveness of the limiters in preventing departure from controlled flight. The simulation was conducted in two phases, the first consisting of open-loop point stability evaluations over a range of subsonic flight conditions, the second concentrating on closed-loop tracking of a preprogrammed target in low speed, high angle-of-attack air combat maneuvering. The command limiters were effective in preventing departure from controlled flight while permitting competent levels of sustained maneuvering. Parametric variations during the study included the effects of pitch control power and wing-body static margin. Stability and control issues were clearly shown to impact the configuration design.

  14. Physiological effects of solar heat load in a fighter cockpit.

    PubMed

    Nunneley, S A; Myhre, L G

    1976-09-01

    The use of bubble canopies to improve vision in fighter aircraft exposes the cockpit to a high radiant heat load. Incoming sunlight increases the heat stress on crewmembers, both by raising air temperature and by directly heating exposed skin and clothing. An F-15 aircraft at Edwards AFB was modified to permit cockpit ventilation by external ground carts. Eight volunteers from the Test Pilot School were studied during 1-h periods in the closed cockpit, in sun and in shade. Mean cockpit air temperatures were 35.2 degrees C in shade and 51.9 degrees C in sun with PH2O less than 10 torr. The corresponding WBGT's were 22.6 and 36.4 degrees C. Sunlight added significantly to overall heat stress, as indicated by a rising heart rate and evaporative weight loss of 284 g/m2 - h (shade value was 109 g/m2 - hr). Mean skin temperatures were 34.3 degrees C in shade and 35.8 degrees C in sun. Particularly high skin temperatures were observed on the chest, the forehead and the top of the head under the helmet. The legs remained cool due to the flow of conditioned air, and this may explain why rectal temperature showed no meaningful change. Heat stress, which alone poses no physiological hazard, may cause crew performance decrements as well as diminishing acceleration tolerance. Possible means of eliminating or ameliorating these effects are discussed.

  15. Effect of conventional and square stores on the longitudinal aerodynamic characteristics of a fighter aircraft model at supersonic speeds. [in the langley unitary plan wind tunnel

    NASA Technical Reports Server (NTRS)

    Monta, W. J.

    1980-01-01

    The effects of conventional and square stores on the longitudinal aerodynamic characteristics of a fighter aircraft configuration at Mach numbers of 1.6, 1.8, and 2.0 was investigated. Five conventional store configurations and six arrangements of a square store configuration were studied. All configurations of the stores produced small, positive increments in the pitching moment throughout the angle-of-attack range, but the configuration with area ruled wing tanks also had a slight decrease on stability at the higher angles of attack. There were some small changes in lift coefficient because of the addition of the stores, causing the drag increment to vary with the lift coefficient. As a result, there were corresponding changes in the increments of the maximum lift drag ratios. The store drag coefficient based on the cross sectional area of the stores ranged from a maximum of 1.1 for the configuration with three Maverick missiles to a minimum of about .040 for the two MK-84 bombs and the arrangements with four square stores touching or two square stores in tandem. Square stores located side by side yielded about 0.50 in the aft position compared to 0.74 in the forward position.

  16. Fire fighter fatalities 1998–2001: overview with an emphasis on structure related traumatic fatalities

    PubMed Central

    Hodous, T; Pizatella, T; Braddee, R; Castillo, D

    2004-01-01

    Objective: To review the causes of all fire fighter line-of-duty-deaths from 1998 through 2001, and present recommendations for preventing fatalities within the specific subgroup of structure related events. Methods: Fire fighter fatality data from the United States Fire Administration were reviewed and classified into three main categories of injury. Investigations conducted through the National Institute for Occupational Safety and Health (NIOSH) Fire Fighter Fatality Investigation and Prevention Program provided the basis for the recommendations presented in this paper. Results: During the time period from 1998–2001, there were 410 line-of-duty deaths among fire fighters in the United States, excluding the 343 fire fighters who died at the World Trade Center on 11 September 2001. The 410 fatalities included 191 medical (non-traumatic) deaths (47%), 75 motor vehicle related fatalities (18%), and 144 other traumatic fatalities (35%). The latter group included 68 fatalities that were associated with structures which commonly involved structural collapse, rapid fire progression, and trapped fire fighters. Conclusions: Structural fires pose particular hazards to fire fighters. Additional efforts must be directed to more effectively use what we have learned through the NIOSH investigations and recommendations from published experts in the safety community, consensus standards, and national fire safety organizations to reduce fire fighter fatalities during structural fire fighting. PMID:15314049

  17. Identification of aerodynamic models for maneuvering aircraft

    NASA Technical Reports Server (NTRS)

    Chin, Suei; Lan, C. Edward

    1990-01-01

    Due to the requirement of increased performance and maneuverability, the flight envelope of a modern fighter is frequently extended to the high angle-of-attack regime. Vehicles maneuvering in this regime are subjected to nonlinear aerodynamic loads. The nonlinearities are due mainly to three-dimensional separated flow and concentrated vortex flow that occur at large angles of attack. Accurate prediction of these nonlinear airloads is of great importance in the analysis of a vehicle's flight motion and in the design of its flight control system. A satisfactory evaluation of the performance envelope of the aircraft may require a large number of coupled computations, one for each change in initial conditions. To avoid the disadvantage of solving the coupled flow-field equations and aircraft's motion equations, an alternate approach is to use a mathematical modeling to describe the steady and unsteady aerodynamics for the aircraft equations of motion. Aerodynamic forces and moments acting on a rapidly maneuvering aircraft are, in general, nonlinear functions of motion variables, their time rate of change, and the history of maneuvering. A numerical method was developed to analyze the nonlinear and time-dependent aerodynamic response to establish the generalized indicial function in terms of motion variables and their time rates of change.

  18. Sea Fighter Analysis

    DTIC Science & Technology

    2007-02-01

    which is used by the model to drive the normal activities of the crew (Figure C.1-2). These routines consist of a sequential list of high- level...separately. Figure C.1-3: Resources & Logic Sheet C.1.1.4 Scenario The scenario that is performed during a model run is a sequential list of all...were marked with a white fore and aft lineup stripe on both landing spots. Current Sea Fighter design does not provide a hangar; however, there

  19. The Next Lightweight Fighter: Not Your Grandfather’s Combat Aircraft

    DTIC Science & Technology

    2013-08-01

    devastat- ing Arabian quake in Somalia, which has almost no infrastructure and suffers from ongoing clan warfare. The United States deployed forces to...Kassim, which the quake had virtually leveled. A joint task force based in Djibouti stood up to direct the relief effort, exercising airborne com- mand...the earth prevent low-altitude or dis- tant aircraft from looking into “the next valley” directly. Consequently, many a reconnaissance mission or

  20. Modal control theory and application to aircraft lateral handling qualities design

    NASA Technical Reports Server (NTRS)

    Srinathkumar, S.

    1978-01-01

    A multivariable synthesis procedure based on eigenvalue/eigenvector assignment is reviewed and is employed to develop a systematic design procedure to meet the lateral handling qualities design objectives of a fighter aircraft over a wide range of flight conditions. The closed loop modal characterization developed provides significant insight into the design process and plays a pivotal role in the synthesis of robust feedback systems. The simplicity of the synthesis algorithm yields an efficient computer aided interactive design tool for flight control system synthesis.

  1. Buffet induced structural/flight-control system interaction of the X-29A aircraft

    NASA Technical Reports Server (NTRS)

    Voracek, David F.; Clarke, Robert

    1991-01-01

    High angle-of-attack flight regime research is currently being conducted for modern fighter aircraft at the NASA Ames Research Center's Dryden Flight Research Facility. This flight regime provides enhanced maneuverability to fighter pilots in combat situations. Flight research data are being acquired to compare and validate advanced computational fluid dynamic solutions and wind-tunnel models. High angle-of-attack flight creates unique aerodynamic phenomena including wing rock and buffet on the airframe. These phenomena increase the level of excitation of the structural modes, especially on the vertical and horizontal stabilizers. With high gain digital flight-control systems, this structural response may result in an aeroservoelastic interaction. A structural interaction on the X-29A aircraft was observed during high angle-of-attack flight testing. The roll and yaw rate gyros sensed the aircraft's structural modes at 11, 13, and 16 Hz. The rate gyro output signals were then amplified through the flight-control laws and sent as commands to the flaperons and rudder. The flight data indicated that as the angle of attack increased, the amplitude of the buffet on the vertical stabilizer increased, which resulted in more excitation to the structural modes. The flight-control system sensors and command signals showed this increase in modal power at the structural frequencies up to a 30 degree angle-of-attack. Beyond a 30 degree angle-of-attack, the vertical stabilizer response, the feedback sensor amplitude, and control surface command signal amplitude remained relatively constant. Data are presented that show the increased modal power in the aircraft structural accelerometers, the feedback sensors, and the command signals as a function of angle of attack. This structural interaction is traced from the aerodynamic buffet to the flight-control surfaces.

  2. Subsonic Maneuvering Effectiveness of High Performance Aircraft Which Employ Quasi-Static Shape Change Devices

    NASA Technical Reports Server (NTRS)

    Montgomery, Raymond C.; Scott, Michael A.; Weston, Robert P.

    1998-01-01

    This paper represents an initial study on the use of quasi-static shape change devices in aircraft maneuvering. The macroscopic effects and requirements for these devices in flight control are the focus of this study. Groups of devices are postulated to replace the conventional leading-edge flap (LEF) and the all-moving wing tip (AMT) on the tailless LMTAS-ICE (Lockheed Martin Tactical Aircraft Systems - Innovative Control Effectors) configuration. The maximum quasi-static shape changes are 13.8% and 7.7% of the wing section thickness for the LEF and AMT replacement devices, respectively. A Computational Fluid Dynamics (CFD) panel code is used to determine the control effectiveness of groups of these devices. A preliminary design of a wings-leveler autopilot is presented. Initial evaluation at 0.6 Mach at 15,000 ft. altitude is made through batch simulation. Results show small disturbance stability is achieved, however, an increase in maximum distortion is needed to statically offset five degrees of sideslip. This only applies to the specific device groups studied, encouraging future research on optimal device placement.

  3. Association of aircraft noise stress to periodontal disease in aircrew members.

    PubMed

    Haskell, B S

    1975-08-01

    A review of the literature reveals a multitude of effects that noise may contribute to periodontal disease, including cardiovascular disease, angiospasm of peripheral vessels, hypertension, and an increase in inflammatory cells with concurrent inhibition of healing. Three groups of 25 men were selected from the Pennsylvania Air National Guard for study. Group 1 consisted of F-102 jet fighter pilots; Group 2, pilots and crew of a four-engine, propeller-driven C-121 aircraft; and Group 3, enlisted men not exposed to aircraft noise, as a control. The degree of alveolar, intraceptal bone loss for each subject was measured from full-mouth radiographs of all groups. The greatest amount of bone loss occurred in crew members of propeller-driven aircraft. Jet pilots had considerably less bone loss while the average number of millimeters of bone lost per tooth revealed a difference between the three groups to the 0.01 significance level (F=24.7). The data suggests there is a degree of alveolar bone loss over a period of years associated with exposure to propeller aircraft noise and vibration, and negligible loss for jet aircraft noise.

  4. Application of the concept of dynamic trim control and nonlinear system inverses to automatic control of a vertical attitude takeoff and landing aircraft

    NASA Technical Reports Server (NTRS)

    Smith, G. A.; Meyer, G.

    1981-01-01

    A full envelope automatic flight control system based on nonlinear inverse systems concepts has been applied to a vertical attitude takeoff and landing (VATOL) fighter aircraft. A new method for using an airborne digital aircraft model to perform the inversion of a nonlinear aircraft model is presented together with the results of a simulation study of the nonlinear inverse system concept for the vertical-attitude hover mode. The system response to maneuver commands in the vertical attitude was found to be excellent; and recovery from large initial offsets and large disturbances was found to be very satisfactory.

  5. Aerodynamics model for a generic ASTOVL lift-fan aircraft

    NASA Technical Reports Server (NTRS)

    Birckelbaw, Lourdes G.; Mcneil, Walter E.; Wardwell, Douglas A.

    1995-01-01

    This report describes the aerodynamics model used in a simulation model of an advanced short takeoff and vertical landing (ASTOVL) lift-fan fighter aircraft. The simulation model was developed for use in piloted evaluations of transition and hover flight regimes, so that only low speed (M approximately 0.2) aerodynamics are included in the mathematical model. The aerodynamic model includes the power-off aerodynamic forces and moments and the propulsion system induced aerodynamic effects, including ground effects. The power-off aerodynamics data were generated using the U.S. Air Force Stability and Control Digital DATCOM program and a NASA Ames in-house graphics program called VORVIEW which allows the user to easily analyze arbitrary conceptual aircraft configurations using the VORLAX program. The jet-induced data were generated using the prediction methods of R. E. Kuhn et al., as referenced in this report.

  6. 76 FR 31613 - NIOSH Fire Fighter Fatality Investigation and Prevention Program (FFFIPP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... NIOSH-063B] NIOSH Fire Fighter Fatality Investigation and Prevention Program (FFFIPP) AGENCY: The... Fire Fighter Fatality Investigation and Prevention Program (FFFIPP). NIOSH is seeking stakeholder input on the FFFIPP to ensure that the program is meeting the needs and expectations of the U.S. fire...

  7. Concepts and application of dynamic separation for agility and super-maneuverability of aircraft: An assessment

    NASA Technical Reports Server (NTRS)

    Freymuth, Peter

    1992-01-01

    Aims for improvement of fighter aircraft pursued by the unsteady flow community are high agility (the ability of the aircraft to make close turns in a low-speed regime) and super maneuverability (the ability of the aircraft to operate at high angles of attack in a post stall regime during quick maneuvers in a more extended speed range). High agility requires high lift coefficients at low speeds in a dynamic situation and this requirement can be met by dynamically forced separation or by quasistatic stall control. The competing methods will be assessed based on the known physics. Maneuvering into the post stall regime also involves dynamic separation but because even fast maneuvers involving the entire aircraft are 'aerodynamically slow' the resulting dynamic vortex structures should be considered 'elicited' rather than 'forced.' More work seems to be needed in this area of elicited dynamic separation.

  8. Damage-mitigating control of aircraft for high performance and life extension

    NASA Astrophysics Data System (ADS)

    Caplin, Jeffrey

    1998-12-01

    A methodology is proposed for the synthesis of a Damage-Mitigating Control System for a high-performance fighter aircraft. The design of such a controller involves consideration of damage to critical points of the structure, as well as the performance requirements of the aircraft. This research is interdisciplinary, and brings existing knowledge in the fields of unsteady aerodynamics, structural dynamics, fracture mechanics, and control theory together to formulate a new approach towards aircraft flight controller design. A flexible wing model is formulated using the Finite Element Method, and the important mode shapes and natural frequencies are identified. The Doublet Lattice Method is employed to develop an unsteady flow model for computation of the unsteady aerodynamic loads acting on the wing due to rigid-body maneuvers and structural deformation. These two models are subsequently incorporated into a pre-existing nonlinear rigid-body aircraft flight-dynamic model. A family of robust Damage-Mitigating Controllers is designed using the Hinfinity-optimization and mu-synthesis method. In addition to weighting the error between the ideal performance and the actual performance of the aircraft, weights are also placed on the strain amplitude at the root of each wing. The results show significant savings in fatigue life of the wings while retaining the dynamic performance of the aircraft.

  9. Lift-fan aircraft: Lessons learned-the pilot's perspective

    NASA Technical Reports Server (NTRS)

    Gerdes, Ronald M.

    1993-01-01

    This paper is written from an engineering test pilot's point of view. Its purpose is to present lift-fan 'lessons learned' from the perspective of first-hand experience accumulated during the period 1962 through 1988 while flight testing vertical/short take-off and landing (V/STOL) experimental aircraft and evaluating piloted engineering simulations of promising V/STOL concepts. Specifically, the scope of the discussions to follow is primarily based upon a critical review of the writer's personal accounts of 30 hours of XV-5A/B and 2 hours of X-14A flight testing as well as a limited simulator evaluation of the Grumman Design 755 lift-fan aircraft. Opinions of other test pilots who flew these aircraft and the aircraft simulator are also included and supplement the writer's comments. Furthermore, the lessons learned are presented from the perspective of the writer's flying experience: 10,000 hours in 100 fixed- and rotary-wing aircraft including 330 hours in 5 experimental V/STOL research aircraft. The paper is organized to present to the reader a clear picture of lift-fan lessons learned from three distinct points of view in order to facilitate application of the lesson principles to future designs. Lessons learned are first discussed with respect to case histories of specific flight and simulator investigations. These principles are then organized and restated with respect to four selected design criteria categories in Appendix I. Lastly, Appendix Il is a discussion of the design of a hypothetical supersonic short take-off vertical landing (STOVL) fighter/attack aircraft.

  10. The sharing of radiological images by professional mixed martial arts fighters on social media.

    PubMed

    Rahmani, George; Joyce, Cormac W; McCarthy, Peter

    2017-06-01

    Mixed martial arts is a sport that has recently enjoyed a significant increase in popularity. This rise in popularity has catapulted many of these "cage fighters" into stardom and many regularly use social media to reach out to their fans. An interesting result of this interaction on social media is that athletes are sharing images of their radiological examinations when they sustain an injury. To review instances where mixed martial arts fighters shared images of their radiological examinations on social media and in what context they were shared. An Internet search was performed using the Google search engine. Search terms included "MMA," "mixed martial arts," "injury," "scan," "X-ray," "fracture," and "break." Articles which discussed injuries to MMA fighters were examined and those in which the fighter themselves shared a radiological image of their injury on social media were identified. During our search, we identified 20 MMA fighters that had shared radiological images of their injuries on social media. There were 15 different types of injury, with a fracture of the mid-shaft of the ulna being the most common. The most popular social media platform was Twitter. The most common imaging modality X-ray (71%). The majority of injuries were sustained during competition (81%) and 35% of these fights resulted in a win for the fighter. Professional mixed martial artists are sharing radiological images of their injuries on social media. This may be in an attempt to connect with fans and raise their profile among other fighters.

  11. Lateral stability and control derivatives of a jet fighter airplane extracted from flight test data by utilizing maximum likelihood estimation

    NASA Technical Reports Server (NTRS)

    Parrish, R. V.; Steinmetz, G. G.

    1972-01-01

    A method of parameter extraction for stability and control derivatives of aircraft from flight test data, implementing maximum likelihood estimation, has been developed and successfully applied to actual lateral flight test data from a modern sophisticated jet fighter. This application demonstrates the important role played by the analyst in combining engineering judgment and estimator statistics to yield meaningful results. During the analysis, the problems of uniqueness of the extracted set of parameters and of longitudinal coupling effects were encountered and resolved. The results for all flight runs are presented in tabular form and as time history comparisons between the estimated states and the actual flight test data.

  12. Near-maximal ECG stress testing and coronary artery disease risk factor analysis in Los Angeles City fire fighters.

    PubMed

    Barnard, R J; Gardner, G W; Diaco, N V; Kattus, A A

    1975-11-01

    Near-maximal ECG stress testing and coronary artery disease risk factor analysis including blood pressure, serum cholesterol and smoking habits were conducted on a randomly selected group (N=90) of Los Angeles City Fire Fighters ranging in age from 40 to 59 yrs. The data obtained from the fire fighters were compared to data previously reported for a group of Los Angeles insurance underwriters of the same age range. Only 12% of the fire fighters had cholesterol values greater than 260 mg% while 18% of the insurance executives fell into this category. Only 2% of the fire fighters had blood pressure values greater than 160/90 mm Hg while 25% of the insurance executives were hypertensive. Thirty-two percent of the fire fighters were smokers at the time of testing as compared to 26% for the insurance executives. Only one fire fighter had all three risk factors elevated and only five had two risk factors elevated. Forty-seven of the fire fighters had no risk factors elevated. Ten percent of the fire fighters had ischemic stress tests as compared to 8% for the insurance executives. Of the nine fire fighters with ischemic stress tests one was hypertensive, one had elevated serum triglycerides, and three were smokers at the time of testing. Since the fire fighters are a medically-selected population with low risk factors for CHD, the observed incidence of ischemic stress tests is surprising and suggests that ischemic heart disease may be job associated.

  13. [Structural-functional reserves of the vegetative nervous system in pilots flying high maneuver aircrafts].

    PubMed

    Sukhoterin, A F; Pashchenko, P S

    2014-01-01

    Purpose of the work was to analyze morbidity among pilots of different categories of aircraft, and to investigate reactivity of the vegetative nervous system (VNS) in pilots flying high maneuver aircrafts varying in age and flying time. Morbidity was deduced from the data of aviation medical exams. The VNS investigation involved 56 pilots of fighter and assault aircrafts both in the inter-flight periods and during duty shifts. Cytochemistry was used to measure glycogen in peripheral blood neutrophils in 77 pilots. It was shown that the pre-stress condition in pilots with the flying time more than 1000 hours may transform to chronic stress, provided that the flight duties remain heavy. According to the cytochemical data, concentration of neutrophilic glycogen indicating the energy potential of peripheral blood leukocytes is controlled by hormones secreted by the VNS sympathetic and parasympathetic components.

  14. Sneaker Males Affect Fighter Male Body Size and Sexual Size Dimorphism in Salmon.

    PubMed

    Weir, Laura K; Kindsvater, Holly K; Young, Kyle A; Reynolds, John D

    2016-08-01

    Large male body size is typically favored by directional sexual selection through competition for mates. However, alternative male life-history phenotypes, such as "sneakers," should decrease the strength of sexual selection acting on body size of large "fighter" males. We tested this prediction with salmon species; in southern populations, where sneakers are common, fighter males should be smaller than in northern populations, where sneakers are rare, leading to geographical clines in sexual size dimorphism (SSD). Consistent with our prediction, fighter male body size and SSD (fighter male∶female size) increase with latitude in species with sneaker males (Atlantic salmon Salmo salar and masu salmon Oncorhynchus masou) but not in species without sneakers (chum salmon Oncorhynchus keta and pink salmon Oncorhynchus gorbuscha). This is the first evidence that sneaker males affect SSD across populations and species, and it suggests that alternative male mating strategies may shape the evolution of body size.

  15. Effects of fire fighter protective ensembles on mobility and performance.

    PubMed

    Coca, Aitor; Williams, W Jon; Roberge, Raymond J; Powell, Jeffrey B

    2010-07-01

    Many studies have shown that fire fighter turnout gear and equipment may restrict mobility. The restriction of movement is usually due to a decrease in range of motion (ROM). It is important to know how much the decrease in ROM affects performance. The aim of this study was to determine the effects of fire fighter protective ensembles on mobility and performance by measuring static and dynamic range of motion (ROM) and job-related tasks. Eight healthy adults (5 males, 3 females), aged 20-40 years, participated in this study. The study consisted of measuring a battery of motions and fire fighter specific tasks while wearing a standard fire fighter ensemble (SE) or regular light clothing (baseline or BL). Several BL ROM tests were significantly (p < 0.05) different from the SE test, including a decrease in shoulder flexion, cervical rotation and flexion, trunk lateral flexion, and stand and reach. There was a significant decrease in time from SE to baseline performing the one-arm search task and object lift. These overall findings support the need for a comprehensive ergonomic evaluation of protective clothing systems to ascertain human factors issues. The development of a Standard Ergonomics Test Practice for further use in laboratories that conduct personal protective systems evaluations using human test subjects is recommended. Published by Elsevier Ltd.

  16. Three-Dimensional Measurement Applied in Design Eye Point of Aircraft Cockpits.

    PubMed

    Wang, Yanyan; Guo, Xiaochao; Liu, Qingfeng; Xiao, Huajun; Bai, Yu

    2018-04-01

    Inappropriate design eye point (DEP) will lead to nonstandard sitting postures, including nonneutral head positions and other uncomfortable sitting postures, which are high risk factors for neck pain in fighter pilots exposed to high G forces. Therefore, application of a 3D measurement method to collect data regarding eye position while in the cruising sitting posture in the aircraft cockpit to guide the design eye point has been proposed. A total of 304 male fixed wing aircraft pilots were divided into two groups. Subgroup A (N = 48) were studied to define the cruising posture during flight. Subgroup B (N = 256) were studied with Romer 3D measurement equipment to locate the cruising eye position of the pilots in a simulated cockpit. The 3D data were compared to DEP data in the current standard cockpit. According to 3D measurement, the vertical distance from the cruising eye point to the neutral seat reference point was 759 mm, which is 36 mm lower than that of the Chinese standard DEP and also lower than the U.S. military standard. The horizontal distance was 131 mm, which is 24 mm shorter than that of the Chinese standard. The current DEP data cannot fulfill the needs of fighter pilots and should be amended according to the results of the 3D measurement so that pilots can acquire the optimal cruising posture in flight. This new method has the value of practical application to investigate cockpit ergonomics and the measurement data can guide DEP design.Wang Y, Guo X, Liu Q, Xiao H, Bai Y. Three-dimensional measurement applied in design eye point of aircraft cockpits. Aerosp Med Hum Perform. 2018; 89(4):371-376.

  17. Determinants of maximal oxygen uptake (VO2 max) in fire fighter testing.

    PubMed

    Vandersmissen, G J M; Verhoogen, R A J R; Van Cauwenbergh, A F M; Godderis, L

    2014-07-01

    The aim of this study was to evaluate current daily practice of aerobic capacity testing in Belgian fire fighters. The impact of personal and test-related parameters on the outcome has been evaluated. Maximal oxygen uptake (VO2 max) results of 605 male fire fighters gathered between 1999 and 2010 were analysed. The maximal cardio respiratory exercise tests were performed at 22 different centres using different types of tests (tread mill or bicycle), different exercise protocols and measuring equipment. Mean VO2 max was 43.3 (SD = 9.8) ml/kg.min. Besides waist circumference and age, the type of test, the degree of performance of the test and the test centre were statistically significant determinants of maximal oxygen uptake. Test-related parameters have to be taken into account when interpreting and comparing maximal oxygen uptake tests of fire fighters. It highlights the need for standardization of aerobic capacity testing in the medical evaluation of fire fighters. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  18. Definition and verification of a complex aircraft for aerodynamic calculations

    NASA Technical Reports Server (NTRS)

    Edwards, T. A.

    1986-01-01

    Techniques are reviewed which are of value in CAD/CAM CFD studies of the geometries of new fighter aircraft. In order to refine the computations of the flows to take advantage of the computing power available from supercomputers, it is often necessary to interpolate the geometry of the mesh selected for the numerical analysis of the aircraft shape. Interpolating the geometry permits a higher level of detail in calculations of the flow past specific regions of a design. A microprocessor-based mathematics engine is described for fast image manipulation and rotation to verify that the interpolated geometry will correspond to the design geometry in order to ensure that the flow calculations will remain valid through the interpolation. Applications of the image manipulation system to verify geometrical representations with wire-frame and shaded-surface images are described.

  19. The nuclear receptor tailless is required for neurogenesis in the adult subventricular zone

    PubMed Central

    Liu, Hai-Kun; Belz, Thorsten; Bock, Dagmar; Takacs, Andrea; Wu, Hui; Lichter, Peter; Chai, Minqiang; Schütz, Günther

    2008-01-01

    The tailless (Tlx) gene encodes an orphan nuclear receptor that is expressed by neural stem/progenitor cells in the adult brain of the subventricular zone (SVZ) and the dentate gyrus (DG). The function of Tlx in neural stem cells of the adult SVZ remains largely unknown. We show here that in the SVZ of the adult brain Tlx is exclusively expressed in astrocyte-like B cells. An inducible mutation of the Tlx gene in the adult brain leads to complete loss of SVZ neurogenesis. Furthermore, analysis indicates that Tlx is required for the transition from radial glial cells to astrocyte-like neural stem cells. These findings demonstrate the crucial role of Tlx in the generation and maintenance of NSCs in the adult SVZ in vivo. PMID:18794344

  20. Blended Buffet-Load-Alleviation System for Fighter Airplane

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    2005-01-01

    The capability of modern fighter airplanes to sustain flight at high angles of attack and/or moderate angles of sideslip often results in immersion of part of such an airplane in unsteady, separated, vortical flow emanating from its forebody or wings. The flows from these surfaces become turbulent and separated during flight under these conditions. These flows contain significant levels of energy over a frequency band coincident with that of low-order structural vibration modes of wings, fins, and control surfaces. The unsteady pressures applied to these lifting surfaces as a result of the turbulent flows are commonly denoted buffet loads, and the resulting vibrations of the affected structures are known as buffeting. Prolonged exposure to buffet loads has resulted in fatigue of structures on several airplanes. Damage to airplanes caused by buffeting has led to redesigns of airplane structures and increased support costs for the United States Air Force and Navy as well as the armed forces of other countries. Time spent inspecting, repairing, and replacing structures adversely affects availability of aircraft for missions. A blend of rudder-control and piezoelectric- actuator engineering concepts was selected as a basis for the design of a vertical-tail buffet-load-alleviation system for the F/A-18 airplane. In this system, the rudder actuator is used to control the response of the first tail vibrational mode (bending at a frequency near 15 Hz), while directional patch piezoelectric actuators are used to control the second tail vibrational mode (tip torsion at a frequency near 45 Hz). This blend of two types of actuator utilizes the most effective features of each. An analytical model of the aeroservoelastic behavior of the airplane equipped with this system was validated by good agreement with measured results from a full-scale ground test, flight-test measurement of buffet response, and an in-flight commanded rudder frequency sweep. The overall performance of the

  1. Neck muscle activity in fighter pilots wearing night-vision equipment during simulated flight.

    PubMed

    Ang, Björn O; Kristoffersson, Mats

    2013-02-01

    Night-vision goggles (NVG) in jet fighter aircraft appear to increase the risk of neck strain due to increased neck loading. The present aim was, therefore, to evaluate the effect on neck-muscle activity and subjective ratings of head-worn night-vision (NV) equipment in controlled simulated flights. Five experienced fighter pilots twice flew a standardized 2.5-h program in a dynamic flight simulator; one session with NVG and one with standard helmet mockup (control session). Each session commenced with a 1-h simulation at 1 Gz followed by a 1.5-h dynamic flight with repeated Gz profiles varying between 3 and 7 Gz and including aerial combat maneuvers (ACM) at 3-5 Gz. Large head-and-neck movements under high G conditions were avoided. Surface electromyographic (EMG) data was simultaneously measured bilaterally from anterior neck, upper and lower posterior neck, and upper shoulder muscles. EMG activity was normalized as the percentage of pretest maximal voluntary contraction (%MVC). Head-worn equipment (helmet comfort, balance, neck mobility, and discomfort) was rated subjectively immediately after flight. A trend emerged toward greater overall neck muscle activity in NV flight during sustained ACM episodes (10% vs. 8% MVC for the control session), but with no such effects for temporary 3-7 Gz profiles. Postflight ratings for NV sessions emerged as "unsatisfactory" for helmet comfort/neck discomfort. However, this was not significant compared to the control session. Helmet mounted NV equipment caused greater neck muscle activity during sustained combat maneuvers, indicating increased muscle strain due to increased neck loading. In addition, postflight ratings indicated neck discomfort after NV sessions, although not clearly increased compared to flying with standard helmet mockup.

  2. Analysis of augmented aircraft flying qualities through application of the Neal-Smith criterion

    NASA Technical Reports Server (NTRS)

    Bailey, R. E.; Smith, R. E.

    1981-01-01

    The Neal-Smith criterion is examined for possible applications in the evaluation of augmented fighter aircraft flying qualities. Longitudinal and lateral flying qualities are addressed. Based on the application of several longitudinal flying qualities data bases, revisions are proposed to the original criterion. Examples are given which show the revised criterion to be a good discriminator of pitch flying qualities. Initial results of lateral flying qualities evaluation through application of the Neal-Smith criterion are poor. Lateral aircraft configurations whose flying qualities are degraded by roll ratcheting effects map into the Level 1 region of the criterion. A third dimension of the criterion for flying qualities specification is evident. Additional criteria are proposed to incorporate this dimension into the criterion structure for flying qualities analysis.

  3. X-31 Unloading Returning from Paris Air Show

    NASA Technical Reports Server (NTRS)

    1995-01-01

    After being flown in the Paris Air Show in June 1995, the X-31 Enhanced Fighter Maneuverability Technology Demonstrator Aircraft, based at the NASA Dryden Flight Research Center, Edwards Air Force Base, California, is off-loaded from an Air Force Reserve C-5 transport after the ferry flight back to Edwards. At the air show, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved

  4. A Collection of Nonlinear Aircraft Simulations in MATLAB

    NASA Technical Reports Server (NTRS)

    Garza, Frederico R.; Morelli, Eugene A.

    2003-01-01

    Nonlinear six degree-of-freedom simulations for a variety of aircraft were created using MATLAB. Data for aircraft geometry, aerodynamic characteristics, mass / inertia properties, and engine characteristics were obtained from open literature publications documenting wind tunnel experiments and flight tests. Each nonlinear simulation was implemented within a common framework in MATLAB, and includes an interface with another commercially-available program to read pilot inputs and produce a three-dimensional (3-D) display of the simulated airplane motion. Aircraft simulations include the General Dynamics F-16 Fighting Falcon, Convair F-106B Delta Dart, Grumman F-14 Tomcat, McDonnell Douglas F-4 Phantom, NASA Langley Free-Flying Aircraft for Sub-scale Experimental Research (FASER), NASA HL-20 Lifting Body, NASA / DARPA X-31 Enhanced Fighter Maneuverability Demonstrator, and the Vought A-7 Corsair II. All nonlinear simulations and 3-D displays run in real time in response to pilot inputs, using contemporary desktop personal computer hardware. The simulations can also be run in batch mode. Each nonlinear simulation includes the full nonlinear dynamics of the bare airframe, with a scaled direct connection from pilot inputs to control surface deflections to provide adequate pilot control. Since all the nonlinear simulations are implemented entirely in MATLAB, user-defined control laws can be added in a straightforward fashion, and the simulations are portable across various computing platforms. Routines for trim, linearization, and numerical integration are included. The general nonlinear simulation framework and the specifics for each particular aircraft are documented.

  5. Advanced control for airbreathing engines, volume 2: General Electric aircraft engines

    NASA Technical Reports Server (NTRS)

    Bansal, Indar

    1993-01-01

    The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 2 of these reports describes the studies performed by GE Aircraft Engines.

  6. Patent foramen ovale and asymptomatic brain lesions in military fighter pilots.

    PubMed

    Kang, Kyung Wook; Kim, Joon-Tae; Choi, Won-Ho; Park, Won-Ju; Shin, Young Ho; Choi, Kang-Ho

    2014-10-01

    Previous studies have reported higher incidence of white matter lesions (WMLs) in military pilots. The anti-gravity straining maneuver, which fighter military pilots perform numerously during a flight is identical to the valsalva maneuver. We sought to investigate the prevalence of right-to-left shunt (RLS) associated with WMLs in military pilots. A prospective study was performed involving military pilots who visited the Airomedical Center. The pilots underwent brain magnetic resonance imaging (MRI) scan and transcranial Doppler (TCD) with intravenous injection of agitated saline solution for the detection of RLS. Periventricular WMLs (PVWMLs) on MRI were graded using Fazeka's scale, and deep WMLs (DWMLs) were graded using Scheltens's scale. This study included 81 military pilots. RLS on TCD was observed less frequently in non-fighter pilots than in fighter pilots (35.5% vs. 64.5%, p=0.011). Fighter pilot was an independently associated factor with RLS on the TCD. DWMLs were independently associated with RLSs through a patent foramen ovale (PFO) (OR 3.507, 95% CI 1.223-10.055, p=0.02). The results suggest that DWMLs in military pilots may significantly be associated with RLS via PFO. Additional investigations are warranted. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Medical evaluation of fire fighters: How fit are they for duty?

    PubMed

    Davis, P O; Biersner, R J; Barnard, R J; Schamadan, J

    1982-08-01

    Aside from the obvious dangers to life and limb associated with the job, fire fighting subjects the body to environmental and physical stressors that can adversely affect various systems. In fact, the effects of these stressors on the cardiovascular system have made coronary heart disease a greater killer among fire fighters than among other occupational groups. The approach to medical evaluation of fire fighters presented here is based on an appreciation of these stressors.

  8. F8U-3 aircraft

    NASA Image and Video Library

    1959-09-10

    Crusader on runway. Navy aircraft number 6340. L59-6101 caption: The Navy's Vought XF8U-3 Supersonic Fighter was an entirely new design as compared to the earlier F8U Crusader series. This jet plane lost in competition with the McDonnell F4H, however, and was never put into production. Langley used the XF8U-3 in some of the first flight measurements of sonic boom intensity. Photograph published in Engineer in Charge A History of the Langley Aeronautical Laboratory, 1917-1958 by James R. Hansen. Page 507. Caption: Chance Vought F8U-3 airplane used in sonic boom investigation at Wallops, June-August 1959. Photograph published in A New Dimension Wallops Island Flight Test Range: The First Fifteen Years by Joseph Shortal. A NASA publication. Page 672.

  9. Charting a New Path: Modernizing the U.S. Air Force Fighter Pilots Career Development

    DTIC Science & Technology

    2015-12-01

    truly provides no new incentives for undecided fighter pilots and is proving to be an antiquated attempt to maintain the fighter pilot force...growing technological requirements. Weapons shops are responsible for a growing number of responsibilities to support combat operations. Crypto

  10. Euler Technology Assessment - SPLITFLOW Code Applications for Stability and Control Analysis on an Advanced Fighter Model Employing Innovative Control Concepts

    NASA Technical Reports Server (NTRS)

    Jordan, Keith J.

    1998-01-01

    This report documents results from the NASA-Langley sponsored Euler Technology Assessment Study conducted by Lockheed-Martin Tactical Aircraft Systems (LMTAS). The purpose of the study was to evaluate the ability of the SPLITFLOW code using viscous and inviscid flow models to predict aerodynamic stability and control of an advanced fighter model. The inviscid flow model was found to perform well at incidence angles below approximately 15 deg, but not as well at higher angles of attack. The results using a turbulent, viscous flow model matched the trends of the wind tunnel data, but did not show significant improvement over the Euler solutions. Overall, the predictions were found to be useful for stability and control design purposes.

  11. A recombinant tail-less integrin beta 4 subunit disrupts hemidesmosomes, but does not suppress alpha 6 beta 4-mediated cell adhesion to laminins

    PubMed Central

    1995-01-01

    To examine the function of the alpha 6 beta 4 integrin we have determined its ligand-binding ability and overexpressed two potentially dominant negative mutant beta 4 subunits, lacking either the cytoplasmic or extracellular domain, in bladder epithelial 804G cells. The results of cell adhesion and radioligand-binding assays showed that alpha 6 beta 4 is a receptor for several laminin isoforms, including laminin 1, 2, 4, and 5. Overexpression of the tail-less or head-less mutant beta 4 subunit did not suppress alpha 6 beta 4-mediated adhesion to laminins, as both types of transfectants adhered to these ligands in the presence of blocking anti-beta 1 antibodies as well as the controls. However, immunofluorescence experiments indicated that the endogenous alpha 6 beta 4 integrin and other hemidesmosomal markers were not concentrated in hemidesmosomes in cells overexpressing tail- less beta 4, while the distribution of these molecules was not altered in cells overexpressing the head-less subunit. Electron microscopic studies confirmed that cells overexpressing tail-less beta 4 had a drastically reduced number of hemidesmosomes, while cells expressing the head-less subunit had a normal number of these structures. Thus, expression of a tail-less, but not a head-less mutant beta 4 subunit leads to a dominant negative effect on hemidesmosome assembly without suppressing initial adhesion to laminins. We conclude that the alpha 6 beta 4 integrin binds to several laminins and plays an essential role in the assembly and/or stability of hemidesmosomes, that alpha 6 beta 4- mediated adhesion and hemidesmosome assembly have distinct requirements, and that it is possible to use a dominant negative approach to selectively interfere with a specific function of an integrin. PMID:7721947

  12. Fire Fighter Trainer Environmental Considerations

    DTIC Science & Technology

    1981-01-08

    established by the Environmental Protection Agency and various state and local ordinances. At present, the Navy’s fire fighter train- ing facilities use...necessary. All operational capabilities for military communications equipment have been retained. Each training compartment has a local communications...the state or local air pollution-control agencies on a case-by-case basis. 4.2.4 Japanese Air Pollution-Control Regulations. The Japanese Air Quality

  13. Behind the Power Curve: The Regular Air Force Pilots Shortages Effect on Air National Guard Fighter Squadrons

    DTIC Science & Technology

    2016-04-01

    in 2017. Recall from the previous retention section that there is nearly a 50% drop in the total AC fighter pilot inventory available to separate...8 Figure 3. Total Fighter Pilots by Year Group ...................................................................11 Figure 4...important for the Total Force to find an equitable balance and refine the forcing functions to produce, absorb, and sustain the dwindling fighter

  14. Flight Research Building at the Aircraft Engine Research Laboratory

    NASA Image and Video Library

    1942-09-21

    The Flight Research Building at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory is a 272- by 150-foot hangar with an internal height up to 90 feet. The hangar’s massive 37.5-foot-tall and 250-foot-long doors can be opened in sections to suit different size aircraft. The hangar has sheltered a diverse fleet of aircraft over the decades. These have ranged from World War II bombers to Cessna trainers and from supersonic fighter jets to a DC–9 airliner. At the time of this September 1942 photograph, however, the hangar was being used as an office building during the construction of the laboratory. In December of 1941, the Flight Research Building became the lab’s first functional building. Temporary offices were built inside the structure to house the staff while the other buildings were completed. The hangar offices were used for an entire year before being removed in early 1943. It was only then that the laboratory acquired its first aircraft, pilots and flight mechanics. The temporary one-story offices can be seen in this photograph inside the large sliding doors. Also note the vertical lift gate below the NACA logo. The gate was installed so that the tails of larger aircraft could pass into the hangar. The white Farm House that served as the Administration Building during construction can be seen in the distance to the left of the hangar.

  15. The sharing of radiological images by professional mixed martial arts fighters on social media

    PubMed Central

    Joyce, Cormac W; McCarthy, Peter

    2017-01-01

    Background Mixed martial arts is a sport that has recently enjoyed a significant increase in popularity. This rise in popularity has catapulted many of these “cage fighters” into stardom and many regularly use social media to reach out to their fans. An interesting result of this interaction on social media is that athletes are sharing images of their radiological examinations when they sustain an injury. Purpose To review instances where mixed martial arts fighters shared images of their radiological examinations on social media and in what context they were shared. Material and Methods An Internet search was performed using the Google search engine. Search terms included “MMA,” “mixed martial arts,” “injury,” “scan,” “X-ray,” “fracture,” and “break.” Articles which discussed injuries to MMA fighters were examined and those in which the fighter themselves shared a radiological image of their injury on social media were identified. Results During our search, we identified 20 MMA fighters that had shared radiological images of their injuries on social media. There were 15 different types of injury, with a fracture of the mid-shaft of the ulna being the most common. The most popular social media platform was Twitter. The most common imaging modality X-ray (71%). The majority of injuries were sustained during competition (81%) and 35% of these fights resulted in a win for the fighter. Conclusion Professional mixed martial artists are sharing radiological images of their injuries on social media. This may be in an attempt to connect with fans and raise their profile among other fighters. PMID:28717518

  16. Effects of nozzle interfairing modifications on longitudinal aerodynamic characteristics of a twin jet, variable wing sweep fighter model

    NASA Technical Reports Server (NTRS)

    Reubush, D. E.; Mercer, C. E.

    1975-01-01

    A wind-tunnel investigation has been made to determine the effects of nozzle interfairing modifications on the longitudinal aerodynamic characteristics of a twin-jet, variable-wing-sweep fighter model. The model was tested in the Langley 16-foot transonic tunnel at Mach numbers of 0.6 to 1.3 and angles of attack from about minus 2 deg to 6 deg and in the Langley 4-foot supersonic presure tunnel at a Mach number of 2.2 and an angle of attack of 0 deg. Compressed air was used to simulate nozzle exhaust flow at jet total-pressure ratios from 1 (jet off) to about 21. The results of this investigation show that the aircraft drag can be significantly reduced by replacing the basic interfairing with a modified interfairing.

  17. Landing impact studies of a 0.3-scale model air cushion landing system for a Navy fighter airplane

    NASA Technical Reports Server (NTRS)

    Leland, T. J. W.; Thompson, W. C.

    1975-01-01

    An experimental study was conducted in order to determine the landing-impact behavior of a 0.3-scale, dynamically (but not physically) similar model of a high-density Navy fighter equipped with an air cushion landing system. The model was tested over a range of landing contact attitudes at high forward speeds and sink rates on a specialized test fixture at the Langley aircraft landing loads and traction facility. The investigation indicated that vertical acceleration at landing impact was highly dependent on the pitch angle at ground contact, the higher acceleration of approximately 5g occurring near zero body-pitch attitude. A limited number of low-speed taxi tests were made in order to determine model stability characteristics. The model was found to have good pitch-damping characteristics but stability in roll was marginal.

  18. Lyapunov-based control of limit cycle oscillations in uncertain aircraft systems

    NASA Astrophysics Data System (ADS)

    Bialy, Brendan

    Store-induced limit cycle oscillations (LCO) affect several fighter aircraft and is expected to remain an issue for next generation fighters. LCO arises from the interaction of aerodynamic and structural forces, however the primary contributor to the phenomenon is still unclear. The practical concerns regarding this phenomenon include whether or not ordnance can be safely released and the ability of the aircrew to perform mission-related tasks while in an LCO condition. The focus of this dissertation is the development of control strategies to suppress LCO in aircraft systems. The first contribution of this work (Chapter 2) is the development of a controller consisting of a continuous Robust Integral of the Sign of the Error (RISE) feedback term with a neural network (NN) feedforward term to suppress LCO behavior in an uncertain airfoil system. The second contribution of this work (Chapter 3) is the extension of the development in Chapter 2 to include actuator saturation. Suppression of LCO behavior is achieved through the implementation of an auxiliary error system that features hyperbolic functions and a saturated RISE feedback control structure. Due to the lack of clarity regarding the driving mechanism behind LCO, common practice in literature and in Chapters 2 and 3 is to replicate the symptoms of LCO by including nonlinearities in the wing structure, typically a nonlinear torsional stiffness. To improve the accuracy of the system model a partial differential equation (PDE) model of a flexible wing is derived (see Appendix F) using Hamilton's principle. Chapters 4 and 5 are focused on developing boundary control strategies for regulating the bending and twisting deformations of the derived model. The contribution of Chapter 4 is the construction of a backstepping-based boundary control strategy for a linear PDE model of an aircraft wing. The backstepping-based strategy transforms the original system to a exponentially stable system. A Lyapunov-based stability

  19. A Generic Inner-Loop Control Law Structure for Six-Degree-of-Freedom Conceptual Aircraft Design

    NASA Technical Reports Server (NTRS)

    Cox, Timothy H.; Cotting, M. Christopher

    2005-01-01

    A generic control system framework for both real-time and batch six-degree-of-freedom simulations is presented. This framework uses a simplified dynamic inversion technique to allow for stabilization and control of any type of aircraft at the pilot interface level. The simulation, designed primarily for the real-time simulation environment, also can be run in a batch mode through a simple guidance interface. Direct vehicle-state acceleration feedback is required with the simplified dynamic inversion technique. The estimation of surface effectiveness within real-time simulation timing constraints also is required. The generic framework provides easily modifiable control variables, allowing flexibility in the variables that the pilot commands. A direct control allocation scheme is used to command aircraft effectors. Primary uses for this system include conceptual and preliminary design of aircraft, when vehicle models are rapidly changing and knowledge of vehicle six-degree-of-freedom performance is required. A simulated airbreathing hypersonic vehicle and simulated high-performance fighter aircraft are used to demonstrate the flexibility and utility of the control system.

  20. A Generic Inner-Loop Control Law Structure for Six-Degree-of-Freedom Conceptual Aircraft Design

    NASA Technical Reports Server (NTRS)

    Cox, Timothy H.; Cotting, Christopher

    2005-01-01

    A generic control system framework for both real-time and batch six-degree-of-freedom (6-DOF) simulations is presented. This framework uses a simplified dynamic inversion technique to allow for stabilization and control of any type of aircraft at the pilot interface level. The simulation, designed primarily for the real-time simulation environment, also can be run in a batch mode through a simple guidance interface. Direct vehicle-state acceleration feedback is required with the simplified dynamic inversion technique. The estimation of surface effectiveness within real-time simulation timing constraints also is required. The generic framework provides easily modifiable control variables, allowing flexibility in the variables that the pilot commands. A direct control allocation scheme is used to command aircraft effectors. Primary uses for this system include conceptual and preliminary design of aircraft, when vehicle models are rapidly changing and knowledge of vehicle 6-DOF performance is required. A simulated airbreathing hypersonic vehicle and simulated high-performance fighter aircraft are used to demonstrate the flexibility and utility of the control system.

  1. Application of smart materials for improved flight performance of military aircraft

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kudva, J.; Appa, K.; Martin, C.

    1995-12-31

    This paper discusses on-going work under an ARPA/WL contract to Northrop Grumman entitled {open_quotes}Smart Structures and Materials Development - Smart Wing.{close_quotes} The contract addresses the application of smart materials and smart Structures concepts to enhance the aerodynamic and maneuver performance of military aircraft. Various concepts for adaptive wing and control surfaces are being studied. Specifically, (a) wing span-wise twist control using built-in shape- memory alloy torquing mechanism and (b) cambered leading edge and trailing edge control surfaces using hybrid piezoelectric and SMA actuation, are being evaluated for a 20% model of a modem day fighter aircraft. The potential benefits ofmore » the designs include increased lift for short take-offs, improved high-speed maneuverability, and enhanced control surface effectiveness. These benefits will be quantified by testing the sub-scale model in a transonic wind tunnel next year.« less

  2. Extractive sampling and optical remote sensing of F100 aircraft engine emissions.

    PubMed

    Cowen, Kenneth; Goodwin, Bradley; Joseph, Darrell; Tefend, Matthew; Satola, Jan; Kagann, Robert; Hashmonay, Ram; Spicer, Chester; Holdren, Michael; Mayfield, Howard

    2009-05-01

    The Strategic Environmental Research and Development Program (SERDP) has initiated several programs to develop and evaluate techniques to characterize emissions from military aircraft to meet increasingly stringent regulatory requirements. This paper describes the results of a recent field study using extractive and optical remote sensing (ORS) techniques to measure emissions from six F-15 fighter aircraft. Testing was performed between November 14 and 16, 2006 on the trim-pad facility at Tyndall Air Force Base in Panama City, FL. Measurements were made on eight different F100 engines, and the engines were tested on-wing of in-use aircraft. A total of 39 test runs were performed at engine power levels that ranged from idle to military power. The approach adopted for these tests involved extractive sampling with collocated ORS measurements at a distance of approximately 20-25 nozzle diameters downstream of the engine exit plane. The emission indices calculated for carbon dioxide, carbon monoxide, nitric oxide, and several volatile organic compounds showed very good agreement when comparing the extractive and ORS sampling methods.

  3. US and USSR Military Aircraft and Missile Aerodynamics 1970-1980. A selected, annotated bibliography, volume 1

    NASA Technical Reports Server (NTRS)

    Tuttle, M. H.; Maddalon, D. V.

    1981-01-01

    The purpose of this selected bibliography (281 citations) is to list available, unclassified, unlimited publications which provide aerodynamic data on major aircraft and missiles currently used by the military forces of the United States of America and the Union of Soviet Socialist Republics. Technical disciplines surveyed include aerodynamic performance, static and dynamic stability, stall-spin, flutter, buffet, inlets nozzles, flap performance, and flying qualities. Concentration is on specific aircraft including fighters, bombers, helicopters, missiles, and some work on transports, which are or could be used for military purposes. The bibliography is limited to material published from 1970 to 1980. The publications herein illustrate many of the types of aerodynamic data obtained in the course of aircraft development programs and may therefore provide some guidance in identifying problems to be expected in the conduct of such work. As such, this information may be useful in planning future research programs.

  4. Design, analysis, and control of large transport aircraft utilizing engine thrust as a backup system for the primary flight controls

    NASA Technical Reports Server (NTRS)

    Gerren, Donna S.

    1993-01-01

    A review of accidents that involved the loss of hydraulic flight control systems serves as an introduction to this project. In each of the accidents--involving transport aircraft such as the DC-10, the C-5A, the L-1011, and the Boeing 747--the flight crew attempted to control the aircraft by means of thrust control. Although these incidents had tragic endings, in the absence of control power due to primary control system failure, control power generated by selective application of engine thrust has proven to be a viable alternative. NASA Dryden has demonstrated the feasibility of controlling an aircraft during level flight, approach, and landing conditions using an augmented throttles-only control system. This system has been successfully flown in the flight test simulator for the B-720 passenger transport and the F-15 air superiority fighter and in actual flight tests for the F-15 aircraft. The Douglas Aircraft Company is developing a similar system for the MD-11 aircraft. The project's ultimate goal is to provide data for the development of thrust control systems for mega-transports (600+ passengers).

  5. High Energy Laser on the Joint Strike Fighter: A Reality in 2025?

    DTIC Science & Technology

    2007-02-26

    10 October 2006. 19. Siegman , A.E., Nemes, G., Serna, J. “How to (Maybe) Measure Laser Beam Quality,” in DPSS (Diode Pumped Solid State) Lasers ...AIR WAR COLLEGE AIR UNIVERSITY HIGH ENERGY LASER ON THE JOINT STRIKE FIGHTER A REALITY IN 2025? by Jeffrey A. Hausmann, Lt Col, USAF A...00-00-2007 to 00-00-2007 4. TITLE AND SUBTITLE High Energy Laser on the Joint Strike Fighter a Reality in 2025? 5a. CONTRACT NUMBER 5b. GRANT

  6. The Joint Strike Fighter (JSF) PHM and the Autonomic Logistic Concept: Potential Impact on Aging Aircraft Problems

    DTIC Science & Technology

    2003-02-01

    and highly intelligent aircraft. A major tenet of this discussion will be that robust information sources provided by the PHM system can and will be...and maintainable (R+M) designed intelligent aircraft which encompasses a comprehensive Prognostics and Health Management (PHM) capability to enhance...hydraulic pump has a 90% chance of failing within the next 10 flight hours. This way, maintenance personnel will be able to make intelligent ,.informed

  7. Night vision imaging systems design, integration, and verification in military fighter aircraft

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Cantiello, Maurizio; Toscano, Mario; Fiorini, Pietro; Jia, Huamin; Zammit-Mangion, David

    2012-04-01

    This paper describes the developmental and testing activities conducted by the Italian Air Force Official Test Centre (RSV) in collaboration with Alenia Aerospace, Litton Precision Products and Cranfiled University, in order to confer the Night Vision Imaging Systems (NVIS) capability to the Italian TORNADO IDS (Interdiction and Strike) and ECR (Electronic Combat and Reconnaissance) aircraft. The activities consisted of various Design, Development, Test and Evaluation (DDT&E) activities, including Night Vision Goggles (NVG) integration, cockpit instruments and external lighting modifications, as well as various ground test sessions and a total of eighteen flight test sorties. RSV and Litton Precision Products were responsible of coordinating and conducting the installation activities of the internal and external lights. Particularly, an iterative process was established, allowing an in-site rapid correction of the major deficiencies encountered during the ground and flight test sessions. Both single-ship (day/night) and formation (night) flights were performed, shared between the Test Crews involved in the activities, allowing for a redundant examination of the various test items by all participants. An innovative test matrix was developed and implemented by RSV for assessing the operational suitability and effectiveness of the various modifications implemented. Also important was definition of test criteria for Pilot and Weapon Systems Officer (WSO) workload assessment during the accomplishment of various operational tasks during NVG missions. Furthermore, the specific technical and operational elements required for evaluating the modified helmets were identified, allowing an exhaustive comparative evaluation of the two proposed solutions (i.e., HGU-55P and HGU-55G modified helmets). The results of the activities were very satisfactory. The initial compatibility problems encountered were progressively mitigated by incorporating modifications both in the front and

  8. Development of infrared scene projectors for testing fire-fighter cameras

    NASA Astrophysics Data System (ADS)

    Neira, Jorge E.; Rice, Joseph P.; Amon, Francine K.

    2008-04-01

    We have developed two types of infrared scene projectors for hardware-in-the-loop testing of thermal imaging cameras such as those used by fire-fighters. In one, direct projection, images are projected directly into the camera. In the other, indirect projection, images are projected onto a diffuse screen, which is then viewed by the camera. Both projectors use a digital micromirror array as the spatial light modulator, in the form of a Micromirror Array Projection System (MAPS) engine having resolution of 800 x 600 with mirrors on a 17 micrometer pitch, aluminum-coated mirrors, and a ZnSe protective window. Fire-fighter cameras are often based upon uncooled microbolometer arrays and typically have resolutions of 320 x 240 or lower. For direct projection, we use an argon-arc source, which provides spectral radiance equivalent to a 10,000 Kelvin blackbody over the 7 micrometer to 14 micrometer wavelength range, to illuminate the micromirror array. For indirect projection, an expanded 4 watt CO II laser beam at a wavelength of 10.6 micrometers illuminates the micromirror array and the scene formed by the first-order diffracted light from the array is projected onto a diffuse aluminum screen. In both projectors, a well-calibrated reference camera is used to provide non-uniformity correction and brightness calibration of the projected scenes, and the fire-fighter cameras alternately view the same scenes. In this paper, we compare the two methods for this application and report on our quantitative results. Indirect projection has an advantage of being able to more easily fill the wide field of view of the fire-fighter cameras, which typically is about 50 degrees. Direct projection more efficiently utilizes the available light, which will become important in emerging multispectral and hyperspectral applications.

  9. Former WWII Fighter Pilot Finds New Home Near Family

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues Feature: Senior Living Former WWII Fighter Pilot Finds New Home ... in Kalispell, Mont. Advice On a Move to Senior Living: Investigate your new surroundings. Talk to those ...

  10. Pitch, roll, and yaw moment generator for insect-like tailless flapping-wing MAV

    NASA Astrophysics Data System (ADS)

    Phan, Hoang Vu; Park, Hoon Cheol

    2016-04-01

    In this work, we proposed a control moment generator, which is called Trailing Edge Change (TEC) mechanism, for attitudes change in hovering insect-like tailless flapping-wing MAV. The control moment generator was installed to the flapping-wing mechanism to manipulate the wing kinematics by adjusting the wing roots location symmetrically or asymmetrically. As a result, the mean aerodynamic force center of each wing is relocated and control moments are generated. The three-dimensional wing kinematics captured by three synchronized high-speed cameras showed that the flapping-wing MAV can properly modify the wing kinematics. In addition, a series of experiments were performed using a multi-axis load cell to evaluate the forces and moments generation. The measurement demonstrated that the TEC mechanism produced reasonable amounts of pitch, roll and yaw moments by shifting position of the trailing edges at the wing roots of the flapping-wing MAV.

  11. Reducing Air Force Fighter Pilot Shortages

    DTIC Science & Technology

    2015-12-31

    that active-component fighter pilot requirements (particularly nonflying staff requirements) exceed its capacity to train and provide initial...pilots in the reserve components. This research was sponsored by four elements of the U.S. Air Force: the Deputy Chief of Staff for Operations (AF/A3...the Deputy Chief of Staff for Manpower, Personnel and Services (AF/A1); the Commander, Air Force Reserve Command (AFRC/CC); and the Director, Air

  12. Recycled Bricks: Exploring Opportunities to Reintegrate Returning American Foreign Fighters Using Existing Models

    DTIC Science & Technology

    2016-12-01

    Fighter Travel, 6. 16 Ibid., 6–15. 17 Ibid., 13. 5 United States failed to stop Americans from going abroad to become foreign fighters, and made 32...ethnicity only possess meaning because they connect people socially.130 The different categories that American Muslims classify themselves demonstrate the...Identity.” 133 Ibid., 66. 34 An example is found in American Muslims; they identify all Americans as part of their national in-group, but when

  13. A design procedure for the handling qualities optimization of the X-29A aircraft

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.; Cox, Timothy H.

    1989-01-01

    A design technique for handling qualities improvement was developed for the X-29A aircraft. As with any new aircraft, the X-29A control law designers were presented with a relatively high degree of uncertainty in their mathematical models. The presence of uncertainties, and the high level of static instability of the X-29A caused the control law designers to stress stability and robustness over handling qualities. During flight test, the mathematical models of the vehicle were validated or corrected to match the vehicle dynamic behavior. The updated models were then used to fine tune the control system to provide fighter-like handling characteristics. A design methodology was developed which works within the existing control system architecture to provide improved handling qualities and acceptable stability with a minimum of cost in both implementation as well as software verification and validation.

  14. Transonic Navier-Stokes computations of strake-generated vortex interactions for a fighter-like configuration

    NASA Technical Reports Server (NTRS)

    Reznick, Steve

    1988-01-01

    Transonic Euler/Navier-Stokes computations are accomplished for wing-body flow fields using a computer program called Transonic Navier-Stokes (TNS). The wing-body grids are generated using a program called ZONER, which subdivides a coarse grid about a fighter-like aircraft configuration into smaller zones, which are tailored to local grid requirements. These zones can be either finely clustered for capture of viscous effects, or coarsely clustered for inviscid portions of the flow field. Different equation sets may be solved in the different zone types. This modular approach also affords the opportunity to modify a local region of the grid without recomputing the global grid. This capability speeds up the design optimization process when quick modifications to the geometry definition are desired. The solution algorithm embodied in TNS is implicit, and is capable of capturing pressure gradients associated with shocks. The algebraic turbulence model employed has proven adequate for viscous interactions with moderate separation. Results confirm that the TNS program can successfully be used to simulate transonic viscous flows about complicated 3-D geometries.

  15. A Study on Aircraft Engine Control Systems for Integrated Flight and Propulsion Control

    NASA Astrophysics Data System (ADS)

    Yamane, Hideaki; Matsunaga, Yasushi; Kusakawa, Takeshi

    A flyable FADEC system engineering model incorporating Integrated Flight and Propulsion Control (IFPC) concept is developed for a highly maneuverable aircraft and a fighter-class engine. An overview of the FADEC system and functional assignments for its components such as the Engine Control Unit (ECU) and the Integrated Control Unit (ICU) are described. Overall system reliability analysis, convex analysis and multivariable controller design for the engine, fault detection/redundancy management, and response characteristics of a fuel system are addressed. The engine control performance of the FADEC is demonstrated by hardware-in-the-loop simulation for fast acceleration and thrust transient characteristics.

  16. X-31 Loaded in C-5 Cargo Bay

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The X-31 Enhanced Fighter Maneuverability Technology Demonstrator Aircraft, based at the NASA Dryden Flight Research Center, Edwards Air Force Base, California, is secured inside the fuselage of an Air Force Reserve C-5 transport. The C-5 was used to ferry the X-31 from Europe back to Edwards, after being flown in the Paris Air Show in June 1995. The X-31's right wing, removed so the aircraft could fit inside the C-5, is in the shipping container in the foreground. At the air show, the X-31 demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems to provide controlled flight at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31

  17. Robust integrated flight/propulsion control design for a STOVL aircraft using H-infinity control design techniques

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay

    1993-01-01

    Results are presented from an application of H-infinity control design methodology to a centralized integrated flight/propulsion control (IFPC) system design for a supersonic STOVL fighter aircraft in transition flight. The emphasis is on formulating the H-infinity optimal control synthesis problem such that the critical requirements for the flight and propulsion systems are adequately reflected within the linear, centralized control problem formulation and the resulting controller provides robustness to modeling uncertainties and model parameter variations with flight condition. Detailed evaluation results are presented for a reduced order controller obtained from the improved H-infinity control design showing that the control design meets the specified nominal performance objective as well as provides stability robustness for variations in plant system dynamics with changes in aircraft trim speed within the transition flight envelope.

  18. The effect of smoke inhalation on lung function and airway responsiveness in wildland fire fighters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, D.; Tager, I.B.; Balmes, J.R.

    1992-12-01

    The current study was undertaken to evaluate the effect of smoke on forced expiratory volumes and airway responsiveness in wildland fire fighters during a season of active fire fighting. Sixty-three seasonal and full-time wildland fire fighters from five U.S. Department of Agriculture Forest Service (USDAFS) Hotshot crews in Northern California and Montana completed questionnaires, spirometry, and methacholine challenge testing before and after an active season of fire fighting in 1989. There were significant mean individual declines of 0.09, 0.15, and 0.44 L/s in postseason values of FVC, FEV1, and FEF25-75, respectively, compared with preseason values. There were no consistent significantmore » relationships between mean individual declines of the spirometric parameters and the covariates: sex, smoking history, history of asthma or allergies, years as a fire fighter, upper/lower respiratory symptoms, or membership in a particular Hotshot crew. There was a statistically significant increase in airway responsiveness when comparing preseason methacholine dose-response slopes (DRS) with postseason dose-response slopes (p = 0.02). The increase in airway responsiveness appeared to be greatest in fire fighters with a history of lower respiratory symptoms or asthma, but it was not related to smoking history. These data suggest that wildland fire fighting is associated with decreases in lung function and increases in airway responsiveness independent of a history of cigarette smoking. Our findings are consistent with the results of previous studies of municipal fire fighters.« less

  19. Simulation model of the integrated flight/propulsion control system, displays, and propulsion system for ASTOVL lift-fan aircraft

    NASA Technical Reports Server (NTRS)

    Chung, W. Y. William; Borchers, Paul F.; Franklin, James A.

    1995-01-01

    A simulation model has been developed for use in piloted evaluations of takeoff, transition, hover, and landing characteristics of an advanced, short takeoff, vertical landing lift fan fighter aircraft. The flight/propulsion control system includes modes for several response types which are coupled to the aircraft's aerodynamic and propulsion system effectors through a control selector tailored to the lift fan propulsion system. Head-up display modes for approach and hover, tailored to their corresponding control modes are provided in the simulation. Propulsion system components modeled include a remote lift and a lift/cruise engine. Their static performance and dynamic response are represented by the model. A separate report describes the subsonic, power-off aerodynamics and jet induced aerodynamics in hover and forward flight, including ground effects.

  20. Expanded R&D by Jet-engine-steering Revolution

    NASA Astrophysics Data System (ADS)

    Gal-Or, Benjamin

    2017-11-01

    Since 1987 [1,2,3,4,5] the global jet engine community is facing the historical fact that jet engine steering is gradually replacing canards and the common, often dangerous and obsolete, aerodynamic-only flight control - a fact that (i) has already affected the defense-industrial complex in the US, Russia, China, Japan, S-Korea and India, (ii) has integrated the traditional jet-engine components R&D with advanced aero-electro-physics, stealth technology, thrust vectoring aerodynamics and material science. Moreover, this military revolution is historically due to expand into the civil transport jets domain, [6,7,8,9]. The historical aim of the JES-Revolution remains the same: Replace the common, stall-spin sensitive canards [6] and Aerodynamic-Only-Obsolete-Flight Control ("AOOF Control"). Invented about 100 years ago for propeller-driven air vehicles, it has already been partially replaced for failure to function in WVR-combat post-stall domain, and for the following reasons: In comparison with complete Tail-Less, Canard-Less, Stealth-JES (Figure 5 and References [1,2,3,4,5,6]), the common AOOF Control increases drag, weight, fuel consumption, complexity, cost, and reduces flight safety, stealth, [Low Detectability] and provides zero post-stall, WVR air combat capability while its CANARDS KILL LD & REDUCE JES. Examples of stealth fighter aircraft that have already replaced canards and AOOF-Control where JES provides at least 64 to 0 KILL-RATIO advantage over AOOF-Controlled conventional fighter aircraft: The U.S. JES F-22 and, apparently, the Russian JES-Su-T-50 & 35S, China 2016-J-31, Indian HAL AMCA & FGFA, Japanese JES IHHI ATD-X, S-Korean JES KF-X. Cf. X-44 in Figure 5. Consequently, the jet engine is no longer defined as providing only brute force forward. Instead, it successfully competes with and wins over the wrong, dominating AOOF-Control, at least as a backup flight control whose sole factual domain is currently a well-established, primary flight

  1. Mortality and life expectancy of professional fire fighters in Hamburg, Germany: a cohort study 1950 – 2000

    PubMed Central

    Wagner, Norbert L; Berger, Jürgen; Flesch-Janys, Dieter; Koch, Peter; Köchel, Anja; Peschke, Michel; Ossenbach, Trude

    2006-01-01

    Background The healthy worker effect may hide adverse health effects in hazardous jobs, especially those where physical fitness is required. Fire fighters may serve as a good example because they sometimes are severely exposed to hazardous substances while on the other hand their physical fitness and their strong health surveillance by far exceeds that of comparable persons from the general population. Methods To study this effect a historic cohort study was conducted to assess mortality and life expectancy of professional fire fighters of the City of Hamburg, Germany. Fire departments and trade unions questioned the validity of existing studies from outside Germany because of specific differences in the professional career. No mortality study had been conducted so far in Germany and only few in Europe. Information on all active and retired fire fighters was extracted from personnel records. To assure completeness of data the cohort was restricted to all fire fighters being active on January 1, 1950 or later. Follow up of the cohort ended on June 30th 2000. Vital status was assessed by personnel records, pension fund records and the German residence registries. Mortality of fire fighters was compared to mortality of the Hamburg and German male population by means of standardized mortality ratios. Life expectancy was calculated using life table analysis. Multivariate proportional hazard models were used to assess the effect of seniority, time from first employment, and other occupational characteristics on mortality. Results The cohort consists of 4640 fire fighters accumulating 111796 person years. Vital status could be determined for 98.2% of the cohort. By the end of follow up 1052 person were deceased. Standardized Mortality Ratio (SMR) for the total cohort was 0.79 (95% CI, 0.74–0.84) compared to Hamburg reference data and 0.78 (95% CI, 0.74–0.83) compared to National German reference data. Conditional life expectancy of a 30 year old fire fighter was 45

  2. Large-scale wind-tunnel investigation of a close-coupled canard-delta-wing fighter model through high angles of attack

    NASA Technical Reports Server (NTRS)

    Stoll, F.; Koenig, D. G.

    1983-01-01

    Data obtained through very high angles of attack from a large-scale, subsonic wind-tunnel test of a close-coupled canard-delta-wing fighter model are analyzed. The canard delays wing leading-edge vortex breakdown, even for angles of attack at which the canard is completely stalled. A vortex-lattice method was applied which gave good predictions of lift and pitching moment up to an angle of attack of about 20 deg, where vortex-breakdown effects on performance become significant. Pitch-control inputs generally retain full effectiveness up to the angle of attack of maximum lift, beyond which, effectiveness drops off rapidly. A high-angle-of-attack prediction method gives good estimates of lift and drag for the completely stalled aircraft. Roll asymmetry observed at zero sideslip is apparently caused by an asymmetry in the model support structure.

  3. Fire Fighter Level I-II-III [and] Practical Skills Test. Wisconsin Fire Service Certification Series. Final Revision.

    ERIC Educational Resources Information Center

    Pribyl, Paul F.

    Practical skills tests are provided for fire fighter trainees in the Wisconsin Fire Service Certification Series, Fire Fighter Levels I, II, and III. A course introduction appears first and contains this information: recommended instructional sequence, required facilities, instructional methodology, requirements for certification, course…

  4. Dynamic Function Allocation in Fighter Cockpits.

    DTIC Science & Technology

    1987-06-30

    their ability to play the video game simulation used in this study. This was done in an attempt to conceptually match the subject’s skills to those of...highly trained Air Force pilots. 4 Apparatus Simulation. A single seat fighter cockpit environment was simulated using the F-15 Strike Eagle video game developed...simulator containing three color CRTs. The video game was presented on the CRT located in the HUD position. The subjects controlled the game through a

  5. Acute spinal injury after centrifuge training in asymptomatic fighter pilots.

    PubMed

    Kang, Kyung-Wook; Shin, Young Ho; Kang, Seungcheol

    2015-04-01

    Many countries have hypergravity training centers using centrifuges for pilots to cope with a high gravity (G) environment. The high G training carries potential risk for the development of spinal injury. However, no studies evaluated the influence of centrifuge training on the spines of asymptomatic fighter pilots on a large scale. Study subjects were 991 male fighter pilots with high G training at one institution. Subject variables included information about physical characteristics, flight hours of pilots prior to the training, and G force exposure related factors during training. The two dependent variables were whether the pilots developed acute spinal injury after training and the severity of the injury (major/minor). The incidence of acute spinal injury after high G training was 2.3% (23 of 991 subjects). There were 19 subjects who developed minor injury and 4 subjects who developed a herniated intervertebral disc, which is considered a major injury. In multivariate analysis, only the magnitude of G force during training was significantly related to the development of acute spinal injury. However, there was no significant factor related to the severity of the injury. These results suggest that high G training could cause negative effects on fighter pilots' spines. The magnitude of G force during training seemed to be the most significant factor affecting the occurrence of acute spinal injury.

  6. 75 FR 40845 - Preventing Deaths and Injuries of Fire Fighters Using Risk Management Principles at Structure Fires

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ... NIOSH 141-A] Preventing Deaths and Injuries of Fire Fighters Using Risk Management Principles at Structure Fires AGENCY: National Institute for Occupational Safety and Health (NIOSH) of the Centers for... publication entitled ``Preventing Deaths and Injuries of Fire Fighters Using Risk Management Principles at...

  7. A knowledge-based system design/information tool for aircraft flight control systems

    NASA Technical Reports Server (NTRS)

    Mackall, Dale A.; Allen, James G.

    1991-01-01

    Research aircraft have become increasingly dependent on advanced electronic control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objective. This integration is being accomplished through electronic control systems. Systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary object is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences are reviewed of three highly complex, integrated aircraft programs: the X-29 forward swept wing; the advanced fighter technology integration (AFTI) F-16; and the highly maneuverable aircraft technology (HiMAT) program. Significant operating technologies, and the design errors which cause them, is examined to help identify what functions a system design/informatin tool should provide to assist designers in avoiding errors.

  8. Design of a Low Cost Short Takeoff-vertical Landing Export Fighter/attack Aircraft

    NASA Technical Reports Server (NTRS)

    Belcher, Anne; Bodeker, Dan, III; Miu, Steve; Petro, Laura; Senf, Cary Taylor; Woeltjen, Donald

    1990-01-01

    The design of a supersonic short takeoff and vertical landing (STOVL) aircraft is presented that is suitable for export. An advanced four poster, low bypass turbofan engine is to be used for propulsion. Preliminary aerodynamic analysis is presented covering a determination of CD versus CL, CD versus Mach number, as well as best cruise Mach number and altitude. Component locations are presented and center of gravity determined. Cost minimization is achieved through the use of developed subsystems and standard fabrication techniques using nonexotic materials. Conclusions regarding the viability of the STOVL design are presented.

  9. The Search for an Advanced Fighter: A History from the XF-108 to the Advanced Tactical Fighter

    DTIC Science & Technology

    1986-04-01

    V, ,tt AIR COMMAND AND- STAFF COLLEGE STUDENT REPORT THE SEARCH FOR AN ADVANCED FIGHTER, A HISTORY FROM THE XF-108 TO THE &ELECTE j - MAJOR ROBERT P...expressed in this document are those of the author. They are- J not intended and should not be thought to represent official ideas, attitudes, or policies of...the general public. A loan copy of the document may be obtained from the Air University Interlibrary Loan Service (AULILDEX, Maxwell AFB, Alabama

  10. The Fighters of Lashkar-e-Taiba: Recruitment, Training, Deployment and Death

    DTIC Science & Technology

    2013-04-01

    false. First,  the vast  majority  of  LeT  fighters  are  Pakistani  and  most  are  Punjabi ,  not  Kashmiri.  It  is  noteworthy  that  there  is...this  database  died  in  Indian‐administered  Kashmir.  This  truth,  taken with  the  predominantly  Pakistani‐ Punjabi   origins  of  the  fighters...2002.    RESIDENCE AND RECRUITMENT    Scholars have  long  claimed  that LeT  is primarily  a  Punjabi   organization  and  that  its  membership  is

  11. A Generic Guidance and Control Structure for Six-Degree-of-Freedom Conceptual Aircraft Design

    NASA Technical Reports Server (NTRS)

    Cotting, M. Christopher; Cox, Timothy H.

    2005-01-01

    A control system framework is presented for both real-time and batch six-degree-of-freedom simulation. This framework allows stabilization and control with multiple command options, from body rate control to waypoint guidance. Also, pilot commands can be used to operate the simulation in a pilot-in-the-loop environment. This control system framework is created by using direct vehicle state feedback with nonlinear dynamic inversion. A direct control allocation scheme is used to command aircraft effectors. Online B-matrix estimation is used in the control allocation algorithm for maximum algorithm flexibility. Primary uses for this framework include conceptual design and early preliminary design of aircraft, where vehicle models change rapidly and a knowledge of vehicle six-degree-of-freedom performance is required. A simulated airbreathing hypersonic vehicle and a simulated high performance fighter are controlled to demonstrate the flexibility and utility of the control system.

  12. Injuries to volunteer fire fighters in West Virginia.

    PubMed

    Magnetti, S M; Wyant, W D; Greenwood, J; Roder, N J; Linton, J C; Ducatman, A M

    1999-02-01

    The distribution and characteristics of workplace injuries for West Virginia volunteer fire fighters (VFFs) are described using 1992 workers' compensation data. Most of the injuries occurred in VFFs who were less than 30 years of age (62%). The most common type of injuries were those in the category of lacerations and contusions (28.9%), with a notable percentage of injuries due to smoke inhalation and respiratory problems (13.7%). The proportional rates related to falls in VFFs were almost twice the national figures for the same year (39.3% versus 22.3%). County population density was found to be directly associated with injury rates, even when adjusted for number of responses. Claims statistics mirror a similar geographical trend in overall workers' compensation claims for all injuries in West Virginia. The results of this study provide a foundation for additional follow-up studies in order to develop improved occupational safety policies and target educational programs aimed at the prevention of injuries in volunteer fire fighters. Several findings have already resulted in programmatic recommendations.

  13. CFD to Flight: Some Recent Success Stories of X-Plane Design to Flight Test at the NASA Dryden Flight Research Center

    NASA Technical Reports Server (NTRS)

    Cosentino, Gary B.

    2007-01-01

    Several examples from the past decade of success stories involving the design and flight test of three true X-planes will be described: in particular, X-plane design techniques that relied heavily upon computational fluid dynamics (CFD). Three specific examples chosen from the author s personal experience are presented: the X-36 Tailless Fighter Agility Research Aircraft, the X-45A Unmanned Combat Air Vehicle, and, most recently, the X-48B Blended Wing Body Demonstrator Aircraft. An overview will be presented of the uses of CFD analysis, comparisons and contrasts with wind tunnel testing, and information derived from the CFD analysis that directly related to successful flight test. Some lessons learned on the proper application, and misapplication, of CFD are illustrated. Finally, some highlights of the flight-test results of the three example X-planes will be presented. This overview paper will discuss some of the author s experience with taking an aircraft shape from early concept and three-dimensional modeling through CFD analysis, wind tunnel testing, further refined CFD analysis, and, finally, flight. An overview of the key roles in which CFD plays well during this process, and some other roles in which it does not, are discussed. How wind tunnel testing complements, calibrates, and verifies CFD analysis is also covered. Lessons learned on where CFD results can be misleading are also given. Strengths and weaknesses of the various types of flow solvers, including panel methods, Euler, and Navier-Stokes techniques, are discussed. The paper concludes with the three specific examples, including some flight test video footage of the X-36, the X-45A, and the X-48B.

  14. CFD to Flight: Some Recent Success Stories of X-plane Design to Flight Test at the NASA Dryden Flight Research Center

    NASA Technical Reports Server (NTRS)

    Cosentino, Gary B.

    2007-01-01

    Several examples from the past decade of success stories involving the design and ight test of three true X-planes will be described: in particular, X-plane design techniques that relied heavily upon computational fluid dynamics (CFD). Three specific examples chosen from the authors personal experience are presented: the X-36 Tailless Fighter Agility Research Aircraft, the X-45A Unmanned Combat Air Vehicle, and, most recently, the X-48B Blended Wing Body Demonstrator Aircraft. An overview will be presented of the uses of CFD analysis, comparisons and contrasts with wind tunnel testing, and information derived from the CFD analysis that directly related to successful flight test. Some lessons learned on the proper application, and misapplication, of CFD are illustrated. Finally, some highlights of the flight-test results of the three example X-planes will be presented. This overview paper will discuss some of the authors experience with taking an aircraft shape from early concept and three-dimensional modeling through CFD analysis, wind tunnel testing, further re ned CFD analysis, and, finally, flight. An overview of the key roles in which CFD plays well during this process, and some other roles in which it does not, are discussed. How wind tunnel testing complements, calibrates, and verifies CFD analysis is also covered. Lessons learned on where CFD results can be misleading are also given. Strengths and weaknesses of the various types of ow solvers, including panel methods, Euler, and Navier-Stokes techniques, are discussed. The paper concludes with the three specific examples, including some flight test video footage of the X-36, the X-45A, and the X-48B.

  15. German Foreign Fighters in Syria and Iraq

    DTIC Science & Technology

    2016-03-01

    players of a Saudi semi-professional soccer team mobilized as a group to travel and fight in Iraq.47 Yet the Saudi soccer squad is not the only...as their biographical availability and integration into German society. The study finds that German foreign fighters are primarily mobilized through...MASTER OF ARTS IN SECURITY STUDIES (MIDDLE EAST, SOUTH ASIA, SUB-SAHARAN AFRICA) from the NAVAL POSTGRADUATE SCHOOL March 2016

  16. The Use of Exergy and Decomposition Techniques in the Development of Generic Analysis, and Optimization Methodologies Applicable to the Synthesis/Design of Aircraft/Aerospace Systems

    DTIC Science & Technology

    2006-04-21

    C. M., and Prendergast, J. P., 2002, "Thermial Analysis of Hypersonic Inlet Flow with Exergy -Based Design Methods," International Journal of Applied...parametric study of the PS and its components is first presented in order to show the type of detailed information on internal system losses which an exergy ...Thermoeconomic Isolation Applied to the Optimal Synthesis/Design of an Advanced Fighter Aircraft System," International Journal of Thermodynamics, ICAT

  17. 76 FR 41770 - Notice of Intent (NOI) To Prepare An Environmental Impact Statement (EIS) for Proposed Conversion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-15

    ... Environmental Impact Statement (EIS) for Proposed Conversion to the F-15 Aircraft for the 144th Fighter Wing... conversion to the F-15 aircraft at the 144th Fighter Wing (144 FW) installation at Fresno-Yosemite... action alternatives analyzed will be a conversion from 18 F-16 PAA to 18 F-15 PAA; or conversion to 24 F...

  18. Water-tunnel investigation of concepts for alleviation of adverse inlet spillage interactions with external stores

    NASA Technical Reports Server (NTRS)

    Neuhart, Dan H.; Rhode, Matthew N.

    1990-01-01

    A test was conducted in the NASA Langley 16- by 24-Inch Water Tunnel to study alleviation of the adverse interactions of inlet spillage flow on the external stores of a fighter aircraft. A 1/48-scale model of a fighter aircraft was used to simulate the flow environment around the aircraft inlets and on the downstream underside of the fuselage. A controlled inlet mass flow was simulated by drawing water into the inlets. Various flow control devices were used on the underside of the aircraft model to manipulate the vortical inlet spillage flow.

  19. The F-35 JSF: Beginning of the End for Blue-Water Ops?

    DTIC Science & Technology

    2010-04-06

    DAMAGED BY INGESTING DEBRIS, THE RESULT OF SWITCHING TO A SINGLE-ENGINE AIRCRAFT FOR THE NAW’S PRIMARY FIGHTER. THE LOCKHEED MARTIN F-35 LIGHTNING II JOINT...States Navy Thesis: Single-engine aircraft have long been considered unsuitable for Naval Aviation, but now the future of blue-water operations is...dependent on the success and reliability of an aircraft · powered by a single engine, the Lockheed -Martin F-35Lightning II Joint Strike Fighter

  20. The Caliphates Global Workforce: An Inside Look at the Islamic States Foreign Fighter Paper Trail

    DTIC Science & Technology

    2016-04-01

    The Caliphate’s Global Workforce: An Inside Look at the Islamic State’s Foreign Fighter Paper Trail Brian Dodwell Daniel Milton Don Rassler The...Caliphate’s Global Workforce: An Inside Look at the Islamic State’s Foreign Fighter Paper Trail Brian Dodwell Daniel Milton Don Rassler Combating...Terrorism Center at West Point April 2016 Cover Photo: Image taken from the Islamic State’s Dabiq magazine United States Military Academy www.ctc.usma.edu

  1. Tailless and Atrophin control Drosophila aggression by regulating neuropeptide signalling in the pars intercerebralis

    NASA Astrophysics Data System (ADS)

    Davis, Shaun M.; Thomas, Amanda L.; Nomie, Krystle J.; Huang, Longwen; Dierick, Herman A.

    2014-02-01

    Aggressive behaviour is widespread throughout the animal kingdom. However, its mechanisms are poorly understood, and the degree of molecular conservation between distantly related species is unknown. Here we show that knockdown of tailless (tll) increases aggression in Drosophila, similar to the effect of its mouse orthologue Nr2e1. Tll localizes to the adult pars intercerebralis (PI), which shows similarity to the mammalian hypothalamus. Knockdown of tll in the PI is sufficient to increase aggression and is rescued by co-expressing human NR2E1. Knockdown of Atrophin, a Tll co-repressor, also increases aggression, and both proteins physically interact in the PI. tll knockdown-induced aggression is fully suppressed by blocking neuropeptide processing or release from the PI. In addition, genetically activating PI neurons increases aggression, mimicking the aggression-inducing effect of hypothalamic stimulation. Together, our results suggest that a transcriptional control module regulates neuropeptide signalling from the neurosecretory cells of the brain to control aggressive behaviour.

  2. A knowledge-based system design/information tool for aircraft flight control systems

    NASA Technical Reports Server (NTRS)

    Mackall, Dale A.; Allen, James G.

    1989-01-01

    Research aircraft have become increasingly dependent on advanced control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objectives. This integration is being accomplished through electronic control systems. Because of the number of systems involved and the variety of engineering disciplines, systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control system is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary objective is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences of three highly complex, integrated aircraft programs are reviewed: the X-29 forward-swept wing, the advanced fighter technology integration (AFTI) F-16, and the highly maneuverable aircraft technology (HiMAT) program. Significant operating anomalies and the design errors which cause them, are examined to help identify what functions a system design/information tool should provide to assist designers in avoiding errors.

  3. Re-Educating Jet-Engine-Researchers to Stay Relevant

    NASA Astrophysics Data System (ADS)

    Gal-Or, Benjamin

    2016-06-01

    To stay relevantly supported, jet-engine researchers, designers and operators should follow changing uses of small and large jet engines, especially those anticipated to be used by/in the next generation, JET-ENGINE-STEERED ("JES") fleets of jet drones but fewer, JES-Stealth-Fighter/Strike Aircraft. In addition, some diminishing returns from isolated, non-integrating, jet-engine component studies, vs. relevant, supersonic, shock waves control in fluidic-JES-side-effects on compressor stall dynamics within Integrated Propulsion Flight Control ("IPFC"), and/or mechanical JES, constitute key relevant methods that currently move to China, India, South Korea and Japan. The central roles of the jet engine as primary or backup flight controller also constitute key relevant issues, especially under post stall conditions involving induced engine-stress while participating in crash prevention or minimal path-time maneuvers to target. And when proper instructors are absent, self-study of the JES-STVS REVOLUTION is an updating must, where STVS stands for wing-engine-airframe-integrated, embedded stealthy-jet-engine-inlets, restructured engines inside Stealth, Tailless, canard-less, Thrust Vectoring IFPC Systems. Anti-terror and Airliners Super-Flight-Safety are anticipated to overcome US legislation red-tape that obstructs JES-add-on-emergency-kits-use.

  4. Moving base simulation evaluation of translational rate command systems for STOVL aircraft in hover

    NASA Technical Reports Server (NTRS)

    Franklin, James A.; Stortz, Michael W.

    1996-01-01

    Using a generalized simulation model, a moving-base simulation of a lift-fan short takeoff/vertical landing fighter aircraft has been conducted on the Vertical Motion Simulator at Ames Research Center. Objectives of the experiment were to determine the influence of system bandwidth and phase delay on flying qualities for translational rate command and vertical velocity command systems. Assessments were made for precision hover control and for landings aboard an LPH type amphibious assault ship in the presence of winds and rough seas. Results obtained define the boundaries between satisfactory and adequate flying qualities for these design features for longitudinal and lateral translational rate command and for vertical velocity command.

  5. USAF bioenvironmental noise data handbook. Volume 158: F-106A aircraft, near and far-field noise

    NASA Astrophysics Data System (ADS)

    Rau, T. H.

    1982-05-01

    The USAF F-106A is a single seat, all-weather fighter/interceptor aircraft powered by a J75-P-17 turbojet engine. This report provides measured and extrapolated data defining the bioacoustic environments produced by this aircraft operating on a concrete runup pad for five engine-power conditions. Near-field data are reported for five locations in a wide variety of physical and psychoacoustic measures: overall and band sound pressure levels, C-weighted and A-weighted sound levels, preferred speech interference level, perceived noise levels, and limiting times for total daily exposure of personnel with and without standard Air Force ear protectors. Far-field data measured at 19 locations are normalized to standard meteorological conditions and extrapolated from 75 - 8000 meters to derive sets of equal-value contours for these same seven acoustic measures as functions of angle and distance from the source.

  6. Neural network application to aircraft control system design

    NASA Technical Reports Server (NTRS)

    Troudet, Terry; Garg, Sanjay; Merrill, Walter C.

    1991-01-01

    The feasibility of using artificial neural networks as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research are identified to enhance the practical applicability of neural networks to flight control design.

  7. Neural network application to aircraft control system design

    NASA Technical Reports Server (NTRS)

    Troudet, Terry; Garg, Sanjay; Merrill, Walter C.

    1991-01-01

    The feasibility of using artificial neural network as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research identified to enhance the practical applicability of neural networks to flight control design.

  8. Perceived aggressiveness predicts fighting performance in mixed-martial-arts fighters.

    PubMed

    Trebicky, Vít; Havlícek, Jan; Roberts, S Craig; Little, Anthony C; Kleisner, Karel

    2013-09-01

    Accurate assessment of competitive ability is a critical component of contest behavior in animals, and it could be just as important in human competition, particularly in human ancestral populations. Here, we tested the role that facial perception plays in this assessment by investigating the association between both perceived aggressiveness and perceived fighting ability in fighters' faces and their actual fighting success. Perceived aggressiveness was positively associated with the proportion of fights won, after we controlled for the effect of weight, which also independently predicted perceived aggression. In contrast, perception of fighting ability was confounded by weight, and an association between perceived fighting ability and actual fighting success was restricted to heavyweight fighters. Shape regressions revealed that aggressive-looking faces are generally wider and have a broader chin, more prominent eyebrows, and a larger nose than less aggressive-looking faces. Our results indicate that perception of aggressiveness and fighting ability might cue different aspects of success in male-male physical confrontation.

  9. The usage of phase change materials in fire fighter protective clothing: its effect on thermal protection

    NASA Astrophysics Data System (ADS)

    Zhao, Mengmeng

    2017-12-01

    The thermal protective performance of the fire fighter protective clothing is of vital importance for fire fighters. In the study fabrics treated by phase change materials (PCMs) were applied in the multi-layered fabrics of the fire fighter protective clothing ensemble. The PCM fabrics were placed at the different layers of the clothing and their thermal protective performance were measured by a TPP tester. Results show that with the application of the PCM fabrics the thermal protection of the multi-layered fabrics was greatly increased. The time to reach a second degree burn was largely reduced. The location of the PCM fabrics at the different layers did not affect much on the thermal protective performance. The higher amount of the PCM adds on, the higher thermal protection was brought. The fabrics with PCMs of a higher melting temperature could contribute to higher thermal protection.

  10. Fire Fighter Trainer Environmental Considerations. Phase II.

    DTIC Science & Technology

    1981-07-31

    NL* 2ffffffffffff m0 h~ hEhI J- L 2 2 * S * MICROCOP Y RI SOLM IION Ii SI CI AN I ’If Conrct No. 1111339-79-C-10011, Mod. No. P0007( i SFIRE FIGHTER...Phosphoric and polyphosphoric acids pose a disposal problem because phosphate compounds are environmentally controlled. Because these compounds do not meet the...acidity from use of these compounds in-a firefight- ing situation do not meet the health and safety criteria for an AFFF substitute; therefore, we

  11. A spatial disorientation predictor device to enhance pilot situational awareness regarding aircraft attitude

    NASA Technical Reports Server (NTRS)

    Chelette, T. L.; Repperger, Daniel W.; Albery, W. B.

    1991-01-01

    An effort was initiated at the Armstrong Aerospace Medical Research Laboratory (AAMRL) to investigate the improvement of the situational awareness of a pilot with respect to his aircraft's spatial orientation. The end product of this study is a device to alert a pilot to potentially disorienting situations. Much like a ground collision avoidance system (GCAS) is used in fighter aircraft to alert the pilot to 'pull up' when dangerous flight paths are predicted, this device warns the pilot to put a higher priority on attention to the orientation instrument. A Kalman filter was developed which estimates the pilot's perceived position and orientation. The input to the Kalman filter consists of two classes of data. The first class of data consists of noise parameters (indicating parameter uncertainty), conflict signals (e.g. vestibular and kinesthetic signal disagreement), and some nonlinear effects. The Kalman filter's perceived estimates are now the sum of both Class 1 data (good information) and Class 2 data (distorted information). When the estimated perceived position or orientation is significantly different from the actual position or orientation, the pilot is alerted.

  12. Environmental assessment of an aircraft conversion, Montana Air National Guard, Great Falls, Montana

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Williams, G.; Policastro, A.; Krummel, J.

    1986-08-01

    It is proposed that the 120th Fighter Interceptor Group of the Montana Air National Guard convert from 18 F-106 to 18 F-16 aircraft. Associated with this conversion are building modifications, land acquisition, and facility construction. The environmental assessment determined that the primary impacts of the conversion would be positive. Noise modeling using the NOISEMAP methodology showed that the maximum noise reduction, resulting from the conversion, at any ground receptor point is about 5 dB on the L/sub dn/ scale. The noise reductions vary with the distance of a receptor point from the runways - the greater the distance, the smallermore » the noise reduction. Conversion to the F-16 prior to completion of a ''hush house'' would result in a temporary increase in noise to the southeast of the airport over a commercial and industrial area. In addition, total air pollutant emissions from aircraft operations would be reduced as a consequence of the conversion. No significant adverse impacts are predicted as a result of the conversion from F-106s to F-16s.« less

  13. McDonald XP-85 Airplane in 40x80 foot Wind Tunnel.

    NASA Image and Video Library

    1948-04-08

    Front View of McDonald XP-85 Plan Model. Parasite Airplane designed to be carried in the B-36 bombay (never built) At the time it was the smallest Jet powered airplane. The McDonnell XF-85 Goblin was an American prototype fighter aircraft conceived during World War II by McDonnell Aircraft. It was intended to be deployed from the bomb bay of the giant Convair B-36 bomber as a parasite fighter. The XF-85's intended role was to defend bombers from hostile interceptor aircraft, a need demonstrated during World War II

  14. Proceedings of the 1987 Aircraft/Engine Structural Integrity Program (ASIP/ENSIP) Conference Held in the Hilton Palacio del Rio Hotel, San Antonio, Texas 1-3 December 1987

    DTIC Science & Technology

    1988-06-01

    upgrading of the depot’s FPI inspection facility, In the forme- case, a realistic projection based while augmenting it with enhanced inspection systems...number of models, powers the twin engined F-15 and the single engined F-16 fighter aircraft. It is an augmented turbofan engine in the 25,000 pound...move from an idea in 1972 to reality today for military gas turbine engines. Special acknowledgement is accorded to the Materials Laboratory of the Air

  15. Sacral Variability in Tailless Species: Homo sapiens and Ochotona princeps.

    PubMed

    Tague, Robert G

    2017-05-01

    Homo sapiens is variable in number of sacral vertebrae, and this variability can lead to obstetrical complication. This study uses the comparative method to test the hypothesis that sacral variability in H. sapiens is associated with absence of a tail. Three species of lagomorphs are studied: Ochotona princeps (N = 271), which is tailless, and Lepus californicus (N = 212) and Sylvilagus audubonii (N = 206), which have tails. Results show that O. princeps has (1) higher diversity index for number of sacral vertebrae (0.49) compared to L. californicus (0.25) and S. audubonii (0.26) and (2) significantly higher percentage of individuals with the species-specific nonmodal number of sacral vertebrae (43.9%) compared to L. californicus (14.2%) and S. audubonii (15.5%). Comparison of H. sapiens (N = 1,030; individuals of age 20-39 years) with O. princeps shows similarities between the species in diversity index (also 0.49 in H. sapiens) and percentage of individuals with nonmodal number of sacral vertebrae (37.3% in H. sapiens). Homeotic transformation best explains the results. H. sapiens and O. princeps show propensity for caudal shift at the sacral-caudal border (i.e., homeotic transformation of the first caudal vertebra to a sacral vertebra). Caudal and cranial shift among presacral vertebrae increases or decreases this propensity, respectively. Increase in number of sacral vertebrae in H. sapiens by homeotic transformation reduces pelvic outlet capacity and can be obstetrically hazardous. Anat Rec, 300:798-809, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  16. Euler/Navier-Stokes calculations of transonic flow past fixed- and rotary-wing aircraft configurations

    NASA Technical Reports Server (NTRS)

    Deese, J. E.; Agarwal, R. K.

    1989-01-01

    Computational fluid dynamics has an increasingly important role in the design and analysis of aircraft as computer hardware becomes faster and algorithms become more efficient. Progress is being made in two directions: more complex and realistic configurations are being treated and algorithms based on higher approximations to the complete Navier-Stokes equations are being developed. The literature indicates that linear panel methods can model detailed, realistic aircraft geometries in flow regimes where this approximation is valid. As algorithms including higher approximations to the Navier-Stokes equations are developed, computer resource requirements increase rapidly. Generation of suitable grids become more difficult and the number of grid points required to resolve flow features of interest increases. Recently, the development of large vector computers has enabled researchers to attempt more complex geometries with Euler and Navier-Stokes algorithms. The results of calculations for transonic flow about a typical transport and fighter wing-body configuration using thin layer Navier-Stokes equations are described along with flow about helicopter rotor blades using both Euler/Navier-Stokes equations.

  17. Planning for Recall of Maintenance Manpower

    DTIC Science & Technology

    2015-09-01

    per hour as the MT supporting the reserve unit (assuming no premium is paid for hazard duty or locale adjustment). All tasks assigned to the MTs...fighter aircraft. Under certain conditions, the placement of these technicians in their roles as reserve personnel creates disproportionate economic...loss for the parent unit and the reserve unit. The results of an analysis of the F-15D fighter aircraft indicate that the organization costs of the

  18. Comparison of Measured and Block Structured Simulations for the F-16XL Aircraft

    NASA Technical Reports Server (NTRS)

    Boelens, O. J.; Badcock, K. J.; Elmilgui, A.; Abdol-Hamid, K. S.; Massey, S. J.

    2008-01-01

    This article presents a comparison of the predictions of three RANS codes for flight conditions of the F-16XL aircraft which feature vortical flow. The three codes, ENSOLV, PMB and PAB3D, solve on structured multi-block grids. Flight data for comparison was available in the form of surface pressures, skin friction, boundary layer data and photographs of tufts. The three codes provided predictions which were consistent with expectations based on the turbulence modelling used, which was k- , k- with vortex corrections and an Algebraic Stress Model. The agreement with flight data was good, with the exception of the outer wing primary vortex strength. The confidence in the application of the CFD codes to complex fighter configurations increased significantly through this study.

  19. Equivalent plate modeling for conceptual design of aircraft wing structures

    NASA Technical Reports Server (NTRS)

    Giles, Gary L.

    1995-01-01

    This paper describes an analysis method that generates conceptual-level design data for aircraft wing structures. A key requirement is that this data must be produced in a timely manner so that is can be used effectively by multidisciplinary synthesis codes for performing systems studies. Such a capability is being developed by enhancing an equivalent plate structural analysis computer code to provide a more comprehensive, robust and user-friendly analysis tool. The paper focuses on recent enhancements to the Equivalent Laminated Plate Solution (ELAPS) analysis code that significantly expands the modeling capability and improves the accuracy of results. Modeling additions include use of out-of-plane plate segments for representing winglets and advanced wing concepts such as C-wings along with a new capability for modeling the internal rib and spar structure. The accuracy of calculated results is improved by including transverse shear effects in the formulation and by using multiple sets of assumed displacement functions in the analysis. Typical results are presented to demonstrate these new features. Example configurations include a C-wing transport aircraft, a representative fighter wing and a blended-wing-body transport. These applications are intended to demonstrate and quantify the benefits of using equivalent plate modeling of wing structures during conceptual design.

  20. Common software and interface for different helmet-mounted display (HMD) aircraft symbology sets

    NASA Astrophysics Data System (ADS)

    Mulholland, Fred F.

    2000-06-01

    Different aircraft in different services and countries have their own set of symbology they want displayed on their HMD. Even as flight symbolgy is standardized, there will still be some differences for types of aircraft, different weapons, different sensors, and different countries. As an HMD supplier, we want to provide a system that can be used across all these applications with no changes in the system, including no changes in the software. This HMD system must also provide the flexibility to accommodate new symbology as it is developed over the years, again, with no change in the HMD software. VSI has developed their HMD software to accommodate F-15, F- 16, F-18, and F-22 symbology sets for the Joint Helmet Mounted Cueing System. It also has the flexibility to accommodate the aircraft types and services of the Joint Strike Fighter: Conventional Takeoff and Landing variant for the USAF, Carrier-based Variant for the USN, and the Short Takeoff and Vertical Landing variant for the USMC and U.K. Royal Navy and Air Force. The key to this flexibility is the interface definition. The interface parameters are established at power-on with the download of an interface definition data set. This data set is used to interpret symbology commands from the aircraft OFP during operation and provide graphic commands to the HMD software. This presentation will define the graphics commands, provide an example of how the interface definition data set is defined, and then show how symbology commands produce a display.

  1. Nonlinear analysis and control of an aircraft in the neighbourhood of deep stall

    NASA Astrophysics Data System (ADS)

    Kolb, Sébastien; Hétru, Laurent; Faure, Thierry M.; Montagnier, Olivier

    2017-01-01

    When an aircraft is locked in a stable equilibrium at high angle-of-attack, we have to do with the so-called deep stall which is a very dangerous situation. Airplanes with T-tail are mainly concerned with this phenomenon since the wake of the main wing flows over the horizontal tail and renders it ineffective but other aircrafts such as fighters can also be affected. First the phase portrait and bifurcation diagram are determined and characterized (with three equilibria in a deep stall prone configuration). It allows to diagnose the configurations of aircrafts susceptible to deep stall and also to point out the different types of time evolutions. Several techniques are used in order to determine the basin of attraction of the stable equilibrium at high angle-of-attack. They are based on the calculation of the stable manifold of the saddle-point equilibrium at medium angle-of-attack. Then several ways are explored in order to try to recover from deep stall. They exploits static features (such as curves of pitching moment versus angle-of-attack for full pitch down and full pitch up elevators) or dynamic aspects (excitation of the eigenmodes and improvement of the aerodynamic efficiency of the tail). Finally, some properties of a deep stall prone aircraft are pointed out and some control tools are also implemented. We try also to apply this mathematical results in a concrete situation by taking into account the captors specificities or by estimating the relevant variables thanks to other available information.

  2. Seri Rama: converting a shadow play puppet to Street Fighter.

    PubMed

    Ghani, D B A

    2012-01-01

    Shadow puppet plays, a traditional Malaysian theater art, is slowly losing its appeal to adolescents, who prefer computer games. To help reverse this decline, the authors incorporated the traditional Seri Rama character into the Street Fighter video game. Using modeling, texturing, and animation, they developed a 3D Seri Rama prototype. Users can control Seri Rama with a PlayStation game controller.

  3. Aircraft directional stability and vertical tail design: A review of semi-empirical methods

    NASA Astrophysics Data System (ADS)

    Ciliberti, Danilo; Della Vecchia, Pierluigi; Nicolosi, Fabrizio; De Marco, Agostino

    2017-11-01

    Aircraft directional stability and control are related to vertical tail design. The safety, performance, and flight qualities of an aircraft also depend on a correct empennage sizing. Specifically, the vertical tail is responsible for the aircraft yaw stability and control. If these characteristics are not well balanced, the entire aircraft design may fail. Stability and control are often evaluated, especially in the preliminary design phase, with semi-empirical methods, which are based on the results of experimental investigations performed in the past decades, and occasionally are merged with data provided by theoretical assumptions. This paper reviews the standard semi-empirical methods usually applied in the estimation of airplane directional stability derivatives in preliminary design, highlighting the advantages and drawbacks of these approaches that were developed from wind tunnel tests performed mainly on fighter airplane configurations of the first decades of the past century, and discussing their applicability on current transport aircraft configurations. Recent investigations made by the authors have shown the limit of these methods, proving the existence of aerodynamic interference effects in sideslip conditions which are not adequately considered in classical formulations. The article continues with a concise review of the numerical methods for aerodynamics and their applicability in aircraft design, highlighting how Reynolds-Averaged Navier-Stokes (RANS) solvers are well-suited to attain reliable results in attached flow conditions, with reasonable computational times. From the results of RANS simulations on a modular model of a representative regional turboprop airplane layout, the authors have developed a modern method to evaluate the vertical tail and fuselage contributions to aircraft directional stability. The investigation on the modular model has permitted an effective analysis of the aerodynamic interference effects by moving, changing, and

  4. A flight-test methodology for identification of an aerodynamic model for a V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Bach, Ralph E., Jr.; Mcnally, B. David

    1988-01-01

    Described is a flight test methodology for developing a data base to be used to identify an aerodynamic model of a vertical and short takeoff and landing (V/STOL) fighter aircraft. The aircraft serves as a test bed at Ames for ongoing research in advanced V/STOL control and display concepts. The flight envelope to be modeled includes hover, transition to conventional flight, and back to hover, STOL operation, and normaL cruise. Although the aerodynamic model is highly nonlinear, it has been formulated to be linear in the parameters to be identified. Motivation for the flight test methodology advocated in this paper is based on the choice of a linear least-squares method for model identification. The paper covers elements of the methodology from maneuver design to the completed data base. Major emphasis is placed on the use of state estimation with tracking data to ensure consistency among maneuver variables prior to their entry into the data base. The design and processing of a typical maneuver is illustrated.

  5. Integrated flight/propulsion control design for a STOVL aircraft using H-infinity control design techniques

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Ouzts, Peter J.

    1991-01-01

    Results are presented from an application of H-infinity control design methodology to a centralized integrated flight propulsion control (IFPC) system design for a supersonic Short Takeoff and Vertical Landing (STOVL) fighter aircraft in transition flight. The emphasis is on formulating the H-infinity control design problem such that the resulting controller provides robustness to modeling uncertainties and model parameter variations with flight condition. Experience gained from a preliminary H-infinity based IFPC design study performed earlier is used as the basis to formulate the robust H-infinity control design problem and improve upon the previous design. Detailed evaluation results are presented for a reduced order controller obtained from the improved H-infinity control design showing that the control design meets the specified nominal performance objectives as well as provides stability robustness for variations in plant system dynamics with changes in aircraft trim speed within the transition flight envelope. A controller scheduling technique which accounts for changes in plant control effectiveness with variation in trim conditions is developed and off design model performance results are presented.

  6. Unpredictability of fighter pilots' g duration tolerance by anthropometric and physiological characteristics.

    PubMed

    Park, Myunghwan; Yoo, Seunghoon; Seol, Hyeongju; Kim, Cheonyoung; Hong, Youngseok

    2015-04-01

    While the factors affecting fighter pilots' G level tolerance have been widely accepted, the factors affecting fighter pilots' G duration tolerance have not been well understood. Thirty-eight subjects wearing anti-G suits were exposed to sustained high G forces using a centrifuge. The subjects exerted AGSM and decelerated the centrifuge when they reached the point of loss of peripheral vision. The G profile consisted of a +2.3 G onset rate, +7.3 G single plateau, and -1.6 G offset rate. Each subject's G tolerance time was recorded and the relationship between the tolerance time and the subject's anthropometric and physiological factors were analyzed. The mean tolerance time of the 38 subjects was 31.6 s, and the min and max tolerance times were 20 s and 58 s, respectively. The correlation analysis indicated that none of the factors had statistically significant correlations with the subjects' G duration tolerance. Stepwise multiple regression analysis showed that G duration tolerance was not dependent on any personal factors of the subjects. After the values of personal factors were simplified into 0 or 1, the t-test analysis showed that subjects' heights were inversely correlated with G duration tolerance at a statistically significant level. However, a logistic regression analysis suggested that the effect of the height factor to a pilot's G duration tolerance was too weak to be used as a predictor of a pilot's G tolerance. Fighter pilots' G duration tolerance could not be predicted by pilots' anthropometric and physiological factors.

  7. Combat Leadership: 56th Fighter Group 1943-1944.

    DTIC Science & Technology

    1986-04-01

    September-October 1970, pp. 30-35. Meyer, John C ., Col, USAF. "What Makes a Jet Ace?" Air Trails, October 1952, p. 21. Ritchey, Russell V. "Identifying...A-Ri68 864 COMBAT LEADERSHIP: 56TH FIGHTER GROUP i947-1944(U) AIR 1/1 COMMAND AND STAFF COLL MAXWELL RFB RL T L LENTZ APR 86I ACSC-86-1525...Interlibrary Loan Service (AUL/LDEX, Maxwell AFB, Alabama, 36112) or the Defense Technical Information Center. Request 4 must include the author’s name and

  8. Bell P–63A King Cobra at the Aircraft Engine Research Laboratory

    NASA Image and Video Library

    1944-01-21

    The Army Air Forces lent the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory a Bell P–63A King Cobra in October 1943 to complement the lab's extensive efforts to improve the Allison V–1710 engine. The V–1710-powered P–63A was a single-seat fighter that could reach speeds of 410 miles per hour and an altitude of 43,000 feet. The fighter, first produced in 1942, was an improvement on Bell’s P–39, but persistent performance problems at high altitudes prevented its acceptance by the Air Corps. Instead many of the P–63s were transferred to the Soviet Union. Almost every test facility at the NACA’s engine lab was used to study the Allison V–1710 engine and its supercharger during World War II. Researchers were able to improve the efficiency, capacity and pressure ratio of the supercharger. They found that improved cooling significantly reduced engine knock in the fuel. Once the researchers were satisfied with their improvements, the new supercharger and cooling components were installed on the P–63A. The Flight Research Division first established the aircraft’s normal flight performance parameters such as speed at various altitudes, rate of climb, and peak altitude. Ensuing flights established the performance parameters of the new configuration in order to determine the improved performance. The program increased V–1710’s horsepower from 1650 to 2250.

  9. Flight testing a V/STOL aircraft to identify a full-envelope aerodynamic model

    NASA Technical Reports Server (NTRS)

    Mcnally, B. David; Bach, Ralph E., Jr.

    1988-01-01

    Flight-test techniques are being used to generate a data base for identification of a full-envelope aerodynamic model of a V/STOL fighter aircraft, the YAV-8B Harrier. The flight envelope to be modeled includes hover, transition to conventional flight and back to hover, STOL operation, and normal cruise. Standard V/STOL procedures such as vertical takeoff and landings, and short takeoff and landings are used to gather data in the powered-lift flight regime. Long (3 to 5 min) maneuvers which include a variety of input types are used to obtain large-amplitude control and response excitations. The aircraft is under continuous radar tracking; a laser tracker is used for V/STOL operations near the ground. Tracking data are used with state-estimation techniques to check data consistency and to derive unmeasured variables, for example, angular accelerations. A propulsion model of the YAV-8B's engine and reaction control system is used to isolate aerodynamic forces and moments for model identification. Representative V/STOL flight data are presented. The processing of a typical short takeoff and slow landing maneuver is illustrated.

  10. Effect of wood smoke exposure on vascular function and thrombus formation in healthy fire fighters.

    PubMed

    Hunter, Amanda L; Unosson, Jon; Bosson, Jenny A; Langrish, Jeremy P; Pourazar, Jamshid; Raftis, Jennifer B; Miller, Mark R; Lucking, Andrew J; Boman, Christoffer; Nyström, Robin; Donaldson, Kenneth; Flapan, Andrew D; Shah, Anoop S V; Pung, Louis; Sadiktsis, Ioannis; Masala, Silvia; Westerholm, Roger; Sandström, Thomas; Blomberg, Anders; Newby, David E; Mills, Nicholas L

    2014-12-09

    Myocardial infarction is the leading cause of death in fire fighters and has been linked with exposure to air pollution and fire suppression duties. We therefore investigated the effects of wood smoke exposure on vascular vasomotor and fibrinolytic function, and thrombus formation in healthy fire fighters. In a double-blind randomized cross-over study, 16 healthy male fire fighters were exposed to wood smoke (~1 mg/m³ particulate matter concentration) or filtered air for one hour during intermittent exercise. Arterial pressure and stiffness were measured before and immediately after exposure, and forearm blood flow was measured during intra-brachial infusion of endothelium-dependent and -independent vasodilators 4-6 hours after exposure. Thrombus formation was assessed using the ex vivo Badimon chamber at 2 hours, and platelet activation was measured using flow cytometry for up to 24 hours after the exposure. Compared to filtered air, exposure to wood smoke increased blood carboxyhaemoglobin concentrations (1.3% versus 0.8%; P < 0.001), but had no effect on arterial pressure, augmentation index or pulse wave velocity (P > 0.05 for all). Whilst there was a dose-dependent increase in forearm blood flow with each vasodilator (P < 0.01 for all), there were no differences in blood flow responses to acetylcholine, sodium nitroprusside or verapamil between exposures (P > 0.05 for all). Following exposure to wood smoke, vasodilatation to bradykinin increased (P = 0.003), but there was no effect on bradykinin-induced tissue-plasminogen activator release, thrombus area or markers of platelet activation (P > 0.05 for all). Wood smoke exposure does not impair vascular vasomotor or fibrinolytic function, or increase thrombus formation in fire fighters. Acute cardiovascular events following fire suppression may be precipitated by exposure to other air pollutants or through other mechanisms, such as strenuous physical exertion and dehydration.

  11. Aircrew Sizing Survey 2011

    DTIC Science & Technology

    2014-10-01

    Resource JSF Joint Strike Fighter JPATS Joint Primary Aircraft Training System USMC United States Marine Corps USAF United States Air Force LIST...Surface Anthropometry Resource (CAESAR) was developed for the Joint Strike Fighter (JSF) program. The ACSS was intended to replace the JSF-CAESAR...an aircrew sample was made in 2003 by Hudson et al. They extracted a subset, named JSF CAESAR (Joint Strike Fighter), from the Civilian American and

  12. Aerodynamic configuration development of the highly maneuverable aircraft technology remotely piloted research vehicle

    NASA Technical Reports Server (NTRS)

    Gingrich, P. B.; Child, R. D.; Panageas, G. N.

    1977-01-01

    The aerodynamic development of the highly maneuverable aircraft technology remotely piloted research vehicle (HiMAT/RPRV) from the conceptual design to the final configuration is presented. The design integrates several advanced concepts to achieve a high degree of transonic maneuverability, and was keyed to sustained maneuverability goals while other fighter typical performance characteristics were maintained. When tests of the baseline configuration indicated deficiencies in the technology integration and design techniques, the vehicle was reconfigured to satisfy the subcritical and supersonic requirements. Drag-due-to-lift levels only 5 percent higher than the optimum were obtained for the wind tunnel model at a lift coefficient of 1 for Mach numbers of up to 0.8. The transonic drag rise was progressively lowered with the application of nonlinear potential flow analyses coupled with experimental data.

  13. Expanded envelope concepts for aircraft control-element failure detection and identification

    NASA Technical Reports Server (NTRS)

    Weiss, Jerold L.; Hsu, John Y.

    1988-01-01

    The purpose of this effort was to develop and demonstrate concepts for expanding the envelope of failure detection and isolation (FDI) algorithms for aircraft-path failures. An algorithm which uses analytic-redundancy in the form of aerodynamic force and moment balance equations was used. Because aircraft-path FDI uses analytical models, there is a tradeoff between accuracy and the ability to detect and isolate failures. For single flight condition operation, design and analysis methods are developed to deal with this robustness problem. When the departure from the single flight condition is significant, algorithm adaptation is necessary. Adaptation requirements for the residual generation portion of the FDI algorithm are interpreted as the need for accurate, large-motion aero-models, over a broad range of velocity and altitude conditions. For the decision-making part of the algorithm, adaptation may require modifications to filtering operations, thresholds, and projection vectors that define the various hypothesis tests performed in the decision mechanism. Methods of obtaining and evaluating adequate residual generation and decision-making designs have been developed. The application of the residual generation ideas to a high-performance fighter is demonstrated by developing adaptive residuals for the AFTI-F-16 and simulating their behavior under a variety of maneuvers using the results of a NASA F-16 simulation.

  14. Environmental Assessment for Employment of a Mobile Laser Evaluator System (LES-M) for the 20th Fighter Wing at Shaw Air Force Base, South Carolina

    DTIC Science & Technology

    2004-05-01

    Environmental Assessment for Employment of a Mobile Laser Evaluator System (LES-M) for the 20th Fighter Wing at Shaw Air Force Base, South Carolina...Mobile Laser Evaluator System (LES-M) for the 20th Fighter Wing at Shaw Air Force Base, South Carolina 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...a Mobile Laser Evaluator System (LES-M) for the 20’’ Fighter Wing (20 fW) at Shaw Air Force Base (AFB), South Carolir.a DESCRIPTION OF THE PROPOSED

  15. Diffusion measures indicate fight exposure-related damage to cerebral white matter in boxers and mixed martial arts fighters.

    PubMed

    Shin, W; Mahmoud, S Y; Sakaie, K; Banks, S J; Lowe, M J; Phillips, M; Modic, M T; Bernick, C

    2014-02-01

    Traumatic brain injury is common in fighting athletes such as boxers, given the frequency of blows to the head. Because DTI is sensitive to microstructural changes in white matter, this technique is often used to investigate white matter integrity in patients with traumatic brain injury. We hypothesized that previous fight exposure would predict DTI abnormalities in fighting athletes after controlling for individual variation. A total of 74 boxers and 81 mixed martial arts fighters were included in the analysis and scanned by use of DTI. Individual information and data on fight exposures, including number of fights and knockouts, were collected. A multiple hierarchical linear regression model was used in region-of-interest analysis to test the hypothesis that fight-related exposure could predict DTI values separately in boxers and mixed martial arts fighters. Age, weight, and years of education were controlled to ensure that these factors would not account for the hypothesized effects. We found that the number of knockouts among boxers predicted increased longitudinal diffusivity and transversal diffusivity in white matter and subcortical gray matter regions, including corpus callosum, isthmus cingulate, pericalcarine, precuneus, and amygdala, leading to increased mean diffusivity and decreased fractional anisotropy in the corresponding regions. The mixed martial arts fighters had increased transversal diffusivity in the posterior cingulate. The number of fights did not predict any DTI measures in either group. These findings suggest that the history of fight exposure in a fighter population can be used to predict microstructural brain damage.

  16. Libyan Former Foreign Fighters and Their Effects on the Libyan Revolution

    DTIC Science & Technology

    2012-03-23

    Glocal organizations; Arab Spring; Sinjar Papers; CJSOTF 120; 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 52...the Libyan Islamic Fighting Group (LIFG) ........................................................................ 13 LIFG and Al Qaeda: A “ Glocal ...to be specifically targeted.(27) LIFG and Al Qaeda Connections: A “ Glocal ” Operation(28) FORMER FOREIGN FIGHTERS AND THEIR EFFECTS ON THE LIBYAN

  17. A review of technologies applicable to low-speed flight of high-performance aircraft investigated in the Langley 14- x 22-foot subsonic tunnel

    NASA Technical Reports Server (NTRS)

    Paulson, John W., Jr.; Quinto, P. Frank; Banks, Daniel W.; Kemmerly, Guy T.; Gatlin, Gregory M.

    1988-01-01

    An extensive research program has been underway at the NASA Langley Research Center to define and develop the technologies required for low-speed flight of high-performance aircraft. This 10-year program has placed emphasis on both short takeoff and landing (STOL) and short takeoff and vertical landing (STOVL) operations rather than on regular up and away flight. A series of NASA in-house as well as joint projects have studied various technologies including high lift, vectored thrust, thrust-induced lift, reversed thrust, an alternate method of providing trim and control, and ground effects. These technologies have been investigated on a number of configurations ranging from industry designs for advanced fighter aircraft to generic wing-canard research models. Test conditions have ranged from hover (or static) through transition to wing-borne flight at angles of attack from -5 to 40 deg at representative thrust coefficients.

  18. Fighter pilots' heart rate, heart rate variation and performance during instrument approaches.

    PubMed

    Mansikka, Heikki; Simola, Petteri; Virtanen, Kai; Harris, Don; Oksama, Lauri

    2016-10-01

    Fighter pilots' heart rate (HR), heart rate variation (HRV) and performance during instrument approaches were examined. The subjects were required to fly instrument approaches in a high-fidelity simulator under various levels of task demand. The task demand was manipulated by increasing the load on the subjects by reducing the range at which they commenced the approach. HR and the time domain components of HRV were used as measures of pilot mental workload (PMWL). The findings of this study indicate that HR and HRV are sensitive to varying task demands. HR and HRV were able to distinguish the level of PMWL after which the subjects were no longer able to cope with the increasing task demands and their instrument landing system performance fell to a sub-standard level. The major finding was the HR/HRV's ability to differentiate the sub-standard performance approaches from the high-performance approaches. Practitioner Summary: This paper examined if HR and HRV were sensitive to varying task demands in a fighter aviation environment and if these measures were related to variations in pilot's performance.

  19. Joint Counterair and Theater Missile Defense Doctrine to Defend against Unmanned Aerial Vehicles and Cruise Missiles in Asymmetric Warfare

    DTIC Science & Technology

    2009-02-12

    features an Active Electronic Scan Array ( ASEA ) radar and improved electronics to enhance the capability of current front line fighter aircraft to...equipped with the APG-79 ASEA radar and selected squadrons of Air Force F-16 and F-15E have been approved for ASEA upgrades. Next generation fighter

  20. The Debate is Over: Close Air Support in Korea and Vietnam

    DTIC Science & Technology

    2011-05-03

    F4U Corsair became Marine aviation’s plane of choice. Early models of the Corsair were formidable fighter aircraft best suited for the air...superiority role. By 1944, the Marine Corps made a deliberate effort to transform the Corsair from a fighter to a multi-role fighter- bomber. As such, the F4U...installation of a ten-channel radio facilitated better communications with ground forces. The upgraded Corsair was such an effective ground attack platform

  1. The polymorphism of dopamine receptor D4 (DRD4) and dopamine transporter (DAT) genes in the men with antisocial behaviour and mixed martial arts fighters.

    PubMed

    Cherepkova, Elena V; Maksimov, Vladimir N; Kushnarev, Alexandr P; Shakhmatov, Igor I; Aftanas, Lyubomir I

    2017-09-12

    Variable-number tandem repeat (VNTR) polymorphisms of DRD4 and DAT genes were studied in the Russian and Chechen men convicted of crimes, and two control groups comprised of the MMA fighters and a sample of general population. A group of MMA fighters included only the subjects without history of antisocial behaviour. DNA was isolated by phenol-chloroform extraction from the blood. Genotyping VNTR polymorphisms of the DRD4 and DAT genes were performed by PCR on published methods. Among those convicted of felonies and most grave crimes, carriers of DRD4 long alleles are found more frequently, similarly to the cohort of MMA fighters (lacking criminal record in both paternal lines). The 9/9 DAT genotype carriers are more frequently encountered among the habitual offenders. A frequency of the combination of the DRD4 genotype 4/7 and DAT genotype 10/10 is clearly higher among the convicts of violent crimes and the MMA fighters. One can speculate the presence of a 'controlled aggression' without a predisposition to pathological violence in the MMA fighters. Our study supports the hypothesis of genetic predisposition to different variants of extreme behaviour mediated by genetic determinants involved in the functioning of neuromediator systems including those controlling dopamine pathways.

  2. Effects of aircraft windscreens and canopies on HMT/D aiming accuracy: III

    NASA Astrophysics Data System (ADS)

    Task, H. Lee; Goodyear, Chuck

    1999-07-01

    Modern fighter aircraft windscreens and canopies are typically made of curved, transparent plastic for improved aero-dynamics and bird-strike protection. Since they are curved these transparencies often refract light in such a way that a pilot looking through the transparency will see a target in a location other than where it really is. This effect has been known for many years and methods to correct the aircraft head- up display (HUD) for these angular deviations have been developed and employed. The same problem occurs for helmet- mounted display/trackers (HMD/Ts) used for target acquisition. However, in this case, the pilot can look through any part of the transparency instead of being constrained to just the forward section as in the case of the HUD and his/her head position can be anywhere in a rather large motion box. To explore the magnitude of these aiming errors several F-15, F- 16, F-18, and F-22 transparency systems were measured from a total of 12 different eye positions centered around the HMD Eye (the HMD Eye was defined to be a point 1.25 inches to the right of the aircraft Design Eye). The collection of eye points for assessing HMT/D aiming accuracy were: HMD Eye, 3 inches left and right of HMD Eye, 2 inches above HMD Eye, and 2 inches forward of HMD Eye plus all combinations of these. Results from these measurements along with recommendations regarding means of assessing 'goodness' of correction algorithms are presented.

  3. KSC-08pd3592

    NASA Image and Video Library

    2008-11-07

    CAPE CANAVERAL, Fla. – Standing next to a Starfighter aircraft at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, retired U.S. Air Force Lt. Col. Lee A. Archer Jr., one of the Tuskegee Airmen, shares his experiences as a combat fighter pilot. Earlier, Archer made a special presentation to the Kennedy work force, talking about his years as a combat fighter pilot, civil rights leader and business executive. Archer is the only Tuskegee Airmen fighter pilot to receive the honor “Ace” for shooting down five enemy aircraft during WWII. He retired as Air Force Command Pilot after 30 years of military service, 1941-1971. Archer is at Kennedy to serve as Military Marshall of the 2008 KSC Space & Air Show, Nov. 8-9. Photo credit: NASA/Kim Shiflett

  4. Some effects of external stores on the static stability of fighter airplanes

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1972-01-01

    Fighter airplanes may have a seemingly limitless number of external store arrangements. Some practical considerations and some aerodynamic considerations must be taken into account in the arrangements of the external stores. The nature of the problems concerning the type of store arrangement involved and the type of airplane on which the stores are installed are reported.

  5. Calculation of High Angle of Attack Aerodynamics of Fighter Configurations. Volume 1. Steady

    DTIC Science & Technology

    1991-04-01

    patterns are now well known qualitatively for fighter configurations from extensive wind and water tunnel tests. However, development of quantitative ...Illustration of Flow Features Predicted in the Present Method -55- z -I1 Figure 2. Difinition of Airplane Coordinate Systems -56- zz T .. l y vy.y Mean

  6. Moving base simulation of an integrated flight and propulsion control system for an ejector-augmentor STOVL aircraft in hover

    NASA Technical Reports Server (NTRS)

    Mcneill, Walter, E.; Chung, William W.; Stortz, Michael W.

    1995-01-01

    A piloted motion simulator evaluation, using the NASA Ames Vertical Motion Simulator, was conducted in support of a NASA Lewis Contractual study of the integration of flight and propulsion systems of a STOVL aircraft. Objectives of the study were to validate the Design Methods for Integrated Control Systems (DMICS) concept, to evaluate the handling qualities, and to assess control power usage. The E-7D ejector-augmentor STOVL fighter design served as the basis for the simulation. Handling-qualities ratings were obtained during precision hover and shipboard landing tasks. Handling-qualities ratings for these tasks ranged from satisfactory to adequate. Further improvement of the design process to fully validate the DMICS concept appears to be warranted.

  7. Reconfigurable Flight Control Using Nonlinear Dynamic Inversion with a Special Accelerometer Implementation

    NASA Technical Reports Server (NTRS)

    Bacon, Barton J.; Ostroff, Aaron J.

    2000-01-01

    This paper presents an approach to on-line control design for aircraft that have suffered either actuator failure, missing effector surfaces, surface damage, or any combination. The approach is based on a modified version of nonlinear dynamic inversion. The approach does not require a model of the baseline vehicle (effectors at zero deflection), but does require feedback of accelerations and effector positions. Implementation issues are addressed and the method is demonstrated on an advanced tailless aircraft. An experimental simulation analysis tool is used to directly evaluate the nonlinear system's stability robustness.

  8. Historical background and design evolution of the transonic aircraft technology supercritical wing

    NASA Technical Reports Server (NTRS)

    Ayers, T. G.; Hallissy, J. B.

    1981-01-01

    Two dimensional wind tunnel test results obtained for supercritical airfoils indicated that substantial improvements in aircraft performance at high subsonic speeds could be achieved by shaping the airfoil to improve the supercritical flow above the upper surface. Significant increases in the drag divergence Mach number, the maximum lift coefficient for buffer onset, and the Mach number for buffet onset at a given lift coefficient were demonstrated for the supercritical airfoil, as compared with a NACA 6 series airfoil of comparable thickness. These trends were corroborated by results from three dimensional wind tunnel and flight tests. Because these indicated extensions of the buffet boundaries could provide significant improvements in the maneuverability of a fighter airplane, an exploratory wind tunnel investigation was initiated which demonstrated that significant aerodynamic improvements could be achieved from the direct substitution of a supercritical airfoil on a variable wing sweep multimission airplane model.

  9. EC88-0052-1

    NASA Image and Video Library

    1988-03-29

    View of the right cockpit of the F-111 MAW aircraft. Unlike most fighter aircraft of the time, the F-111 had side-by-side seating. The pilot sat on the left side, and the weapons systems officer on the right. Both had control sticks to fly the aircraft.

  10. Revised Simulation Model of the Control System, Displays, and Propulsion System for a ASTOVL Lift Fan Aircraft

    NASA Technical Reports Server (NTRS)

    Franklin, James A.

    1997-01-01

    This report describes revisions to a simulation model that was developed for use in piloted evaluations of takeoff, transition, hover, and landing characteristics of an advanced short takeoff and vertical landing lift fan fighter aircraft. These revisions have been made to the flight/propulsion control system, head-up display, and propulsion system to reflect recent flight and simulation experience with short takeoff and vertical landing operations. They include nonlinear inverse control laws in all axes (eliminating earlier versions with state rate feedback), throttle scaling laws for flightpath and thrust command, control selector commands apportioned based on relative effectiveness of the individual controls, lateral guidance algorithms that provide more flexibility for terminal area operations, and a simpler representation of the propulsion system. The model includes modes tailored to the phases of the aircraft's operation, with several response types which are coupled to the aircraft's aerodynamic and propulsion system effectors through a control selector tailored to the propulsion system. Head-up display modes for approach and hover are integrated with the corresponding control modes. Propulsion system components modeled include a remote lift fan and a lift-cruise engine. Their static performance and dynamic responses are represented by the model. A separate report describes the subsonic, power-off aerodynamics and jet induced aerodynamics in hover and forward flight, including ground effects.

  11. Investigation of Reynolds Number Effects on a Generic Fighter Configuration in the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Tomek, W. G.; Hall, R. M.; Wahls, R. A.; Luckring, J. M.; Owens, L. R.

    2002-01-01

    A wind tunnel test of a generic fighter configuration was tested in the National Transonic Facility through a cooperative agreement between NASA Langley Research Center and McDonnell Douglas. The primary purpose of the test was to assess Reynolds number scale effects on a thin-wing, fighter-type configuration up to full-scale flight conditions (that is, Reynolds numbers of the order of 60 million). The test included longitudinal and lateral/directional studies at subsonic and transonic conditions across a range of Reynolds numbers from that available in conventional wind tunnels to flight conditions. Results are presented for three Mach numbers (0.6, 0.8, and 0.9) and three configurations: (1) Fuselage/Wing; (2) Fuselage/Wing/Centerline Vertical Tail/Horizontal Tail; and (3) Fuselage/Wing/Trailing-Edge Extension/Twin Vertical Tails. Reynolds number effects on the longitudinal aerodynamic characteristics are presented herein.

  12. Improvements to the adaptive maneuvering logic program

    NASA Technical Reports Server (NTRS)

    Burgin, George H.

    1986-01-01

    The Adaptive Maneuvering Logic (AML) computer program simulates close-in, one-on-one air-to-air combat between two fighter aircraft. Three important improvements are described. First, the previously available versions of AML were examined for their suitability as a baseline program. The selected program was then revised to eliminate some programming bugs which were uncovered over the years. A listing of this baseline program is included. Second, the equations governing the motion of the aircraft were completely revised. This resulted in a model with substantially higher fidelity than the original equations of motion provided. It also completely eliminated the over-the-top problem, which occurred in the older versions when the AML-driven aircraft attempted a vertical or near vertical loop. Third, the requirements for a versatile generic, yet realistic, aircraft model were studied and implemented in the program. The report contains detailed tables which make the generic aircraft to be either a modern, high performance aircraft, an older high performance aircraft, or a previous generation jet fighter.

  13. Reusable Surface Insulation

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Advanced Flexible Reusable Surface Insulation, developed by Ames Research Center, protects the Space Shuttle from the searing heat that engulfs it on reentry into the Earth's atmosphere. Initially integrated into the Space Shuttle by Rockwell International, production was transferred to Hi-Temp Insulation Inc. in 1974. Over the years, Hi-Temp has created many new technologies to meet the requirements of the Space Shuttle program. This expertise is also used commercially, including insulation blankets to cover aircrafts parts, fire barrier material to protect aircraft engine cowlings and aircraft rescue fire fighter suits. A Fire Protection Division has also been established, offering the first suit designed exclusively by and for aircraft rescue fire fighters. Hi-Temp is a supplier to the Los Angeles City Fire Department as well as other major U.S. civil and military fire departments.

  14. Development and flight test experiences with a flight-crucial digital control system

    NASA Technical Reports Server (NTRS)

    Mackall, Dale A.

    1988-01-01

    Engineers and scientists in the advanced fighter technology integration (AFTI) F-16 program investigated the integration of emerging technologies into an advanced fighter aircraft. AFTI's three major technologies included: flight-crucial digital control, decoupled aircraft flight control, and integration of avionics, flight control, and pilot displays. In addition to investigating improvements in fighter performance, researchers studied the generic problems confronting the designers of highly integrated flight-crucial digital control. An overview is provided of both the advantages and problems of integration digital control systems. Also, an examination of the specification, design, qualification, and flight test life-cycle phase is provided. An overview is given of the fault-tolerant design, multimoded decoupled flight control laws, and integrated avionics design. The approach to qualifying the software and system designs is discussed, and the effects of design choices on system qualification are highlighted.

  15. Mortality amongst Paris fire-fighters.

    PubMed

    Deschamps, S; Momas, I; Festy, B

    1995-12-01

    This paper is the first mortality cohort study undertaken in France to examine the association between fire-fighting and cause of death. The cohort investigated in this study consisted of 830 male members of the Brigade des sapeurs-pompiers de Paris (BSPP). These professional had served for a minimum of 5 years on 1 January 1977. They were monitored for a 14 year period, finishing 1 January 1991. When compared to the average French male, the Paris fire-fighters were found to have a far lower overall mortality (SMR = 0.52 [0.35-0.75]). None of the cause specific SMRs were significantly different from unity. However a greater number of deaths than expected was observed for genito-urinary cancer (SMR = 3.29), digestive cancer (SMR = 1.14), respiratory cancer (SMR = 1.12) and 'cerebrovascular disease' (SMR = 1.16). The low overall SMR observed was consistent with the healthy worker effect. As for cause specific SMRs, they will be confirmed or invalidated by a further analysis as the follow-up of this cohort is being carried on.

  16. Application of Sliding Mode Methods to the Design of Reconfigurable Flight Control Systems

    NASA Technical Reports Server (NTRS)

    Wells, Scott R.

    2002-01-01

    Observer-based sliding mode control is investigated for application to aircraft reconfigurable flight control. A comprehensive overview of reconfigurable flight control is given, including, a review of the current state-of-the-art within the subdisciplines of fault detection, parameter identification, adaptive control schemes, and dynamic control allocation. Of the adaptive control methods reviewed, sliding mode control (SMC) appears very promising due its property of invariance to matched uncertainty. An overview of sliding mode control is given and its remarkable properties are demonstrated by example. Sliding mode methods, however, are difficult to implement because unmodeled parasitic dynamics cause immediate and severe instability. This presents a challenge for all practical applications with limited bandwidth actuators. One method to deal with parasitic dynamics is the use of an asymptotic observer in the feedback path. Observer-based SMC is investigated, and a method for selecting observer gains is offered. An additional method for shaping the feedback loop using a filter is also developed. It is shown that this SMC prefilter is equivalent to a form of model reference hedging. A complete design procedure is given which takes advantage of the sliding mode boundary layer to recast the SMC as a linear control law. Frequency domain loop shaping is then used to design the sliding manifold. Finally, three aircraft applications are demonstrated. An F-18/HARV is used to demonstrate a SISO pitch rate tracking controller. It is also used to demonstrate a MIMO lateral-directional roll rate tracking controller. The last application is a full linear six degree-of-freedom advanced tailless fighter model. The observer-based SMC is seen to provide excellent tracking with superior robustness to parameter changes and actuator failures.

  17. Challenging the New World Order: The Arms Transfer Policies of the Russian Republic

    DTIC Science & Technology

    1993-10-01

    SU-22 fighter, SU-24 and SU-25 ground attack planes, MiG-29, MiG-31 fighters, 11-76 transports, " secondhand " AN-24 and Yak-40 passenger aircraft, i.e...notably in the Third World, and is the author of a forthcoming study of the Soviet Commissariat of Nationalities and editor of books on Soviet

  18. ECN-14280

    NASA Image and Video Library

    1980-12-30

    The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.

  19. EC80-14281

    NASA Image and Video Library

    1980-12-30

    The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.

  20. ECN-14273

    NASA Image and Video Library

    1980-12-30

    The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here during a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.

  1. A Communication Protocol for CyAMS and the Cyber Fighter Associate Interface

    DTIC Science & Technology

    2015-05-01

    by David Harman , Scott Brown, Brian Henz, and Lisa M Marvel Approved for public release; distribution unlimited...Laboratory A Communication Protocol for CyAMS and the Cyber Fighter Associate Interface by David Harman College Qualified Leaders Student...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) David Harman , Scott Brown, Brian Henz, and Lisa M Marvel 5d. PROJECT

  2. Cost of ownership for military cargo aircraft using a common versus disparate display configuration

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Most, Marvin C.

    2010-04-01

    A 2009 paper considered possibilities for applying a common display suite to various front-line bubble canopy fighters, whereas further research suggests the cost savings, post Milestone C production/deployment, might not be advantageous. The situation for military cargo and tanker aircraft, may offer a different paradigm. The primary objective of Defense acquisition is to acquire quality products that satisfy user needs with measurable improvements to mission capability and operational support, in a timely manner, and at a fair and reasonable price. DODD 5000.01 specifies that all participants in the acquisition system shall recognize the reality of fiscal constraints, viewing cost as an independent variable. DoD Components must therefore plan programs based on realistic projections of the dollars and manpower likely to be available in future years and also identify the total costs of ownership, as well as the major drivers of total ownership costs. In theory, therefore, this has already been done for existing cargo/tanker aircraft programs accommodating independent, disparate display suites. This paper goes beyond that stage by exploring total costs of ownership for a hypothetical common approach to cargo/tanker display avionics, bounded by looking at a limited number of such aircraft, e.g., C-5, C-17, C-130H (variants), and C-130J. It is the purpose of this paper to reveal whether there are total cost of ownership advantages for a common approach over and above the existing disparate approach. Aside from cost issues, other considerations, i.e., availability and supportability, may also be analyzed.

  3. Moving base simulation of an ASTOVL lift-fan aircraft

    NASA Technical Reports Server (NTRS)

    Chung, William W. Y.; Borchers, Paul F.; Franklin, James A.

    1995-01-01

    Using a generalized simulation model, a moving-base simulation of a lift-fan short takeoff/vertical landing fighter aircraft was conducted on the Vertical Motion Simulator at Ames Research Center. Objectives of the experiment were to (1) assess the effects of lift-fan propulsion system design features on aircraft control during transition and vertical flight including integration of lift fan/lift/cruise engine/aerodynamic controls and lift fan/lift/cruise engine dynamic response, (2) evaluate pilot-vehicle interface with the control system and head-up display including control modes for low-speed operational tasks and control mode/display integration, and (3) conduct operational evaluations of this configuration during takeoff, transition, and landing similar to those carried out previously by the Ames team for the mixed-flow, vectored thrust, and augmentor-ejector concepts. Based on results of the simulation, preliminary assessments of acceptable and borderline lift-fan and lift/cruise engine thrust response characteristics were obtained. Maximum pitch, roll, and yaw control power used during transition, hover, and vertical landing were documented. Control and display mode options were assessed for their compatibility with a range of land-based and shipboard operations from takeoff to cruise through transition back to hover and vertical landing. Flying qualities were established for candidate control modes and displays for instrument approaches and vertical landings aboard an LPH assault ship and DD-963 destroyer. Test pilot and engineer teams from the Naval Air Warfare Center, Boeing, Lockheed, McDonnell Douglas, and the British Defence Research Agency participated in the program.

  4. Extended Range Aerial Delivery Using an Unpowered Autonomous Tailless UAV

    NASA Astrophysics Data System (ADS)

    Kraft, Tyler E.

    An alternative approach for precision aerial delivery utilizing a flying wing for controllable forward glide is presented. Although effective, current delivery methods either display a lack of control, or require close standoff distances, potentially endangering aircraft personnel as well as bystanders. Hardware-in-the-loop simulations provide an efficient method for evaluating various wing designs and actuation configurations. Four control surface configurations are presented and evaluated, encompassing traditional aircraft and ram-air parafoil control approaches. Fixed-wing and multirotor unmanned aircraft-based flight tests were conducted to evaluate the controllability and handling performance of the various configurations of both a fixed wing model and a model with collapsing wings. A manufacturing process was developed to allow repeatable results in the field using cheap, mostly disposable materials. A powered flying wing model was used to maximize data collection in later stages of software development. Data collected during flight tests was used to create a model of the system and develop a Nonlinear Dynamic Inversion controller for autonomous flight. The NDI controller was able to provide stable flight in pitch, but will need more development to control yaw, instead an intentional bias was built in to show proof of concept for direct yaw control. The results demonstrate the feasibility of the flying wing-based aerial delivery; however, significant challenges remain regarding the stability and scalability of the system.

  5. Hypersonic Flight: Time To Go Operational

    DTIC Science & Technology

    2013-02-14

    and turbojet /turbofan driven aircraft both individually and combined with the latter taking over fighter propulsion in 1945-1948 and quickly...2000 2020 Early Turbojet / Turbofan Piston Aircraft Late Turbojet / Turbofan Year Deployed M ile s pe r H ou 6 ensure the...threaten aircraft , airbases, and naval assets, especially aircraft carrier battle groups. The future is uncertain and the preceding vision of the

  6. Defense Inventory: Further Analysis and Enhanced Metrics Could Improve Service Supply and Depot Operations

    DTIC Science & Technology

    2016-06-01

    of and replace. DOD maintains weapon systems (e.g., aircraft and ships) and equipment (e.g., generators and radars) that require regular and...including helicopters, combat vehicles, air defense systems, ships, fighter and bomber aircraft , intercontinental ballistic missiles, jet aircraft ...Defense for Acquisition, Technology, and Logistics. 19In the depot maintenance context, an end item can be a weapon system, such as an aircraft , ship

  7. SRY-box-containing Gene 2 Regulation of Nuclear Receptor Tailless (Tlx) Transcription in Adult Neural Stem Cells*

    PubMed Central

    Shimozaki, Koji; Zhang, Chun-Li; Suh, Hoonkyo; Denli, Ahmet M.; Evans, Ronald M.; Gage, Fred H.

    2012-01-01

    Adult neurogenesis is maintained by self-renewable neural stem cells (NSCs). Their activity is regulated by multiple signaling pathways and key transcription factors. However, it has been unclear whether these factors interplay with each other at the molecular level. Here we show that SRY-box-containing gene 2 (Sox2) and nuclear receptor tailless (TLX) form a molecular network in adult NSCs. We observed that both Sox2 and TLX proteins bind to the upstream region of Tlx gene. Sox2 positively regulates Tlx expression, whereas the binding of TLX to its own promoter suppresses its transcriptional activity in luciferase reporter assays. Such TLX-mediated suppression can be antagonized by overexpressing wild-type Sox2 but not a mutant lacking the transcriptional activation domain. Furthermore, through regions involved in DNA-binding activity, Sox2 and TLX physically interact to form a complex on DNAs that contain a consensus binding site for TLX. Finally, depletion of Sox2 revealed the potential negative feedback loop of TLX expression that is antagonized by Sox2 in adult NSCs. These data suggest that Sox2 plays an important role in Tlx transcription in cultured adult NSCs. PMID:22194602

  8. SRY-box-containing gene 2 regulation of nuclear receptor tailless (Tlx) transcription in adult neural stem cells.

    PubMed

    Shimozaki, Koji; Zhang, Chun-Li; Suh, Hoonkyo; Denli, Ahmet M; Evans, Ronald M; Gage, Fred H

    2012-02-17

    Adult neurogenesis is maintained by self-renewable neural stem cells (NSCs). Their activity is regulated by multiple signaling pathways and key transcription factors. However, it has been unclear whether these factors interplay with each other at the molecular level. Here we show that SRY-box-containing gene 2 (Sox2) and nuclear receptor tailless (TLX) form a molecular network in adult NSCs. We observed that both Sox2 and TLX proteins bind to the upstream region of Tlx gene. Sox2 positively regulates Tlx expression, whereas the binding of TLX to its own promoter suppresses its transcriptional activity in luciferase reporter assays. Such TLX-mediated suppression can be antagonized by overexpressing wild-type Sox2 but not a mutant lacking the transcriptional activation domain. Furthermore, through regions involved in DNA-binding activity, Sox2 and TLX physically interact to form a complex on DNAs that contain a consensus binding site for TLX. Finally, depletion of Sox2 revealed the potential negative feedback loop of TLX expression that is antagonized by Sox2 in adult NSCs. These data suggest that Sox2 plays an important role in Tlx transcription in cultured adult NSCs.

  9. EC79-12055

    NASA Image and Video Library

    1980-01-03

    The HiMAT (Highly Maneuverable Aircraft Technology) subscale research vehicle, seen here after landing to conclude a research flight, was flown by the NASA Dryden Flight Research Center, Edwards, California, from mid 1979 to January 1983. The aircraft demonstrated advanced fighter technologies that have been used in the development of many modern high performance military aircraft.

  10. Lack of Influence of Apolipoprotein E Status on Cognition or Brain Structure in Professional Fighters

    PubMed Central

    Miller, Justin B.; Rissman, Robert A.; Bernick, Charles B.

    2017-01-01

    Abstract The role of the apolipoprotein e4 allele in moderating cognitive and neuroanatomical degeneration following repeated traumatic brain injury is controversial. Here we sought to establish the presence or absence of such a moderating relationship in a prospective study of active and retired boxers and mixed martial arts fighters. Fighters (n = 193) underwent cognitive evaluations, interviews regarding fight history, MRI of the brain, and genetic testing. We used a series of moderator analyses to test for any relationship of apolipoprotein genotype on structural volumes of brain regions previously established to be smaller in those with the most fight exposure, and on cognitive abilities also established to be sensitive to fight exposure. No moderating relationship was detected in any of the analyses. The results of this study suggest that there is no impact of apolipoprotein genotype on the apparent negative association between exposure to professional fighting and brain structure volume or aspects of cognition. PMID:27245878

  11. Air Force F-22 Fighter Program: Background and Issues for Congress

    DTIC Science & Technology

    2009-12-22

    comprises a large share of their overall business.23 The Air Force in 2007 estimated that of about 1,000 first-tier F-22 supplier firms, roughly 110, or...fighter.37 In addition, Boeing, the manufacturer of the F-15, is offering for sale on the international market an upgraded version of the F-15 called...Personally I have no interest in the Silent Eagle because it is only stealthy from the front,” Hirata says, referencing a limitation shared by the

  12. Physiological parameters monitoring of fire-fighters by means of a wearable wireless sensor system

    NASA Astrophysics Data System (ADS)

    Stelios, M.; Mitilineos, Stelios A.; Chatzistamatis, Panagiotis; Vassiliadis, Savvas; Primentas, Antonios; Kogias, Dimitris; Michailidis, Emmanouel T.; Rangoussi, Maria; Kurşun Bahadir, Senem; Atalay, Özgür; Kalaoğlu, Fatma; Sağlam, Yusuf

    2016-03-01

    Physiological parameter monitoring may be useful in many different groups of the population, such as infants, elderly people, athletes, soldiers, drivers, fire-fighters, police etc. This can provide a variety of information ranging from health status to operational readiness. In this article, we focus on the case of first responders and specifically fire-fighters. Firefighters can benefit from a physiological monitoring system that is used to extract multiple indications such as the present position, the possible life risk level, the stress level etc. This work presents a wearable wireless sensor network node, based on low cost, commercial-off- the-self (COTS) electronic modules, which can be easily attached on a standard fire-fighters’ uniform. Due to the low frequency wired interface between the selected electronic components, the proposed solution can be used as a basis for a textile system where all wired connections will be implemented by means of conductive yarn routing in the textile structure, while some of the standard sensors can be replaced by textile ones. System architecture is described in detail, while indicative samples of acquired signals are also presented.

  13. Flow field over the wing of a delta-wing fighter model with vortex control devices at Mach 0.6 to 1.2

    NASA Technical Reports Server (NTRS)

    Bare, E. Ann; Reubush, David E.; Haddad, Raymond C.

    1992-01-01

    As part of a cooperative research program between NASA, McDonnell Douglas Corporation, and Wright Research and Development Center, a flow field investigation was conducted on a 7.52 percent scale windtunnel model of an advanced fighter aircraft design. The investigation was conducted in the Langley 16 ft Transonic Tunnel at Mach numbers of 0.6, 0.9, and 1.2. Angle of attack was varied from -4 degrees to 30 degrees and the model was tested at angles of sideslip of 0, 5, and -5 degrees. Data for the over the wing flow field were obtained at four axial survey stations by the use of six 5 hole conical probes mounted on a survey mechanism. The wing leading edge primary vortex exerted the greatest influence in terms of total pressure loss on the over the wing flow field in the area surveyed. A number of vortex control devices were also investigated. They included two different apex flaps, wing leading edge vortex flaps, and small large wing fences. The vortex flap and both apex flaps were beneficial in controlling the wing leading edge primary vortex.

  14. Environmental Assessment for a Fighter Detachment Facility, Shaw Air Force Base, South Carolina

    DTIC Science & Technology

    2005-04-01

    provides for the protection and propagation of fish, shellfish, wildlife, and recreation in and on the water. The US Army Corps of Engineers (USACE) is...scirpoides Long-beaked baldrush - SC Floating mats in ponds; pond margins. Ruellia caroliniensis A petunia - SC Woods and wood margins. Sagittaria...supply after conventional treatment, fishing, and the survival and propagation of a balanced indigenous aquatic Final EA for a Fighter Detachment

  15. National Nanotechnology Initiative: The Initiative and Its Implementation Plan

    DTIC Science & Technology

    2000-07-01

    precisely controlled size and composition and then to assemble them into larger structures with unique properties and functions will revolutionize...thousand pounds could be stripped from a pilotless fighter aircraft , resulting in longer missions, and fighter agility could be dramatically improved...societal impact: $12 million. e. Major themes and new programs in FY 2001 include : • Nano-biotechnology: biosystems, bio-mimetics and composites (priority

  16. Air National Guard Fighters the Total Force (Maxwell Paper, Number 1)

    DTIC Science & Technology

    1996-05-01

    child abuse cases, 9 percent rise in spousal abuse reports, and an 11 percent rise in alcohol abuse. While these figures represent only one fighter wing, they highlight some of the potential problems that may be encountered by other active duty units as they too struggle under an ever increasing workload. These problems and a growing belief that long-term readiness may soon suffer if the workload is not reduced, convinced Defense Secretary William Perry to direct a greater role for the Air National Guard in peacetime contingency operations. The Air National Guard is no

  17. F-35 Joint Strike Fighter (JSF) Program: Background, Status, and Issues

    DTIC Science & Technology

    2007-07-19

    Buy ‘Hundreds’ of STOVL Joint Strike Fighters,” Inside the Air Force. September 17, 2004. 6 Marc Selinger. “Jumper Confirms Air Force Plans to Cut...concluded that some 230 of the Navy’s projected buy of 480 JSFs could instead be F/A-18E/Fs, depending on the progress of the JSF program and the price of...18E/F Buy Depends on JSF Progress,’Cohen Tells SASC,” Aerospace Daily, May 21, 1997: 285, 288. See also CRS Issue Brief IB93041, C- 17 Cargo

  18. The Human Orphan Nuclear Receptor Tailless (TLX, NR2E1) Is Druggable

    PubMed Central

    Benod, Cindy; Villagomez, Rosa; Filgueira, Carly S.; Hwang, Peter K.; Leonard, Paul G.; Poncet-Montange, Guillaume; Rajagopalan, Senapathy; Fletterick, Robert J.; Gustafsson, Jan-Åke; Webb, Paul

    2014-01-01

    Nuclear receptors (NRs) are an important group of ligand-dependent transcriptional factors. Presently, no natural or synthetic ligand has been identified for a large group of orphan NRs. Small molecules to target these orphan NRs will provide unique resources for uncovering regulatory systems that impact human health and to modulate these pathways with drugs. The orphan NR tailless (TLX, NR2E1), a transcriptional repressor, is a major player in neurogenesis and Neural Stem Cell (NSC) derived brain tumors. No chemical probes that modulate TLX activity are available, and it is not clear whether TLX is druggable. To assess TLX ligand binding capacity, we created homology models of the TLX ligand binding domain (LBD). Results suggest that TLX belongs to an emerging class of NRs that lack LBD helices α1 and α2 and that it has potential to form a large open ligand binding pocket (LBP). Using a medium throughput screening strategy, we investigated direct binding of 20,000 compounds to purified human TLX protein and verified interactions with a secondary (orthogonal) assay. We then assessed effects of verified binders on TLX activity using luciferase assays. As a result, we report identification of three compounds (ccrp1, ccrp2 and ccrp3) that bind to recombinant TLX protein with affinities in the high nanomolar to low micromolar range and enhance TLX transcriptional repressive activity. We conclude that TLX is druggable and propose that our lead compounds could serve as scaffolds to derive more potent ligands. While our ligands potentiate TLX repressive activity, the question of whether it is possible to develop ligands to de-repress TLX activity remains open. PMID:24936658

  19. The human orphan nuclear receptor tailless (TLX, NR2E1) is druggable.

    PubMed

    Benod, Cindy; Villagomez, Rosa; Filgueira, Carly S; Hwang, Peter K; Leonard, Paul G; Poncet-Montange, Guillaume; Rajagopalan, Senapathy; Fletterick, Robert J; Gustafsson, Jan-Åke; Webb, Paul

    2014-01-01

    Nuclear receptors (NRs) are an important group of ligand-dependent transcriptional factors. Presently, no natural or synthetic ligand has been identified for a large group of orphan NRs. Small molecules to target these orphan NRs will provide unique resources for uncovering regulatory systems that impact human health and to modulate these pathways with drugs. The orphan NR tailless (TLX, NR2E1), a transcriptional repressor, is a major player in neurogenesis and Neural Stem Cell (NSC) derived brain tumors. No chemical probes that modulate TLX activity are available, and it is not clear whether TLX is druggable. To assess TLX ligand binding capacity, we created homology models of the TLX ligand binding domain (LBD). Results suggest that TLX belongs to an emerging class of NRs that lack LBD helices α1 and α2 and that it has potential to form a large open ligand binding pocket (LBP). Using a medium throughput screening strategy, we investigated direct binding of 20,000 compounds to purified human TLX protein and verified interactions with a secondary (orthogonal) assay. We then assessed effects of verified binders on TLX activity using luciferase assays. As a result, we report identification of three compounds (ccrp1, ccrp2 and ccrp3) that bind to recombinant TLX protein with affinities in the high nanomolar to low micromolar range and enhance TLX transcriptional repressive activity. We conclude that TLX is druggable and propose that our lead compounds could serve as scaffolds to derive more potent ligands. While our ligands potentiate TLX repressive activity, the question of whether it is possible to develop ligands to de-repress TLX activity remains open.

  20. Investigation of Aerodynamics Scale Effects for a Generic Fighter Configuration in the National Transonic Facility (Invited)

    NASA Technical Reports Server (NTRS)

    Tomek, W. G.; Wahls, R. A.; Owens, L. R.; Burner, A. B.; Graves, S. S.; Luckring, J. M.

    2003-01-01

    Two wind tunnel tests of a generic fighter configuration have been completed in the National Transonic Facility. The primary purpose of the tests was to assess Reynolds number scale effects on a thin-wing, fighter-type configuration up to full-scale flight conditions (that is, Reynolds numbers of the order of 60 million). The tests included longitudinal and lateral/directional studies at subsonic and transonic conditions across a range of Reynolds numbers from that available in conventional wind tunnels to flight conditions. Results are presented for three Mach numbers (0.6, 0.8, and 0.9) and three configurations: 1) Fuselage / Wing, 2) Fuselage / Wing / Centerline Vertical Tail / Horizontal Tail, and 3) Fuselage / Wing / Trailing-Edge Extension / Twin Vertical Tails. Reynolds number effects on the lateral-directional aerodynamic characteristics are presented herein, along with longitudinal data demonstrating the effects of fixing the boundary layer transition location for low Reynolds number conditions. In addition, an improved model videogrammetry system and results are discussed.

  1. Static internal performance of ventral and rear nozzle concepts for short-takeoff and vertical-landing aircraft

    NASA Technical Reports Server (NTRS)

    Re, Richard J.; Carson, George T., Jr.

    1991-01-01

    The internal performance of two exhaust system concepts applicable to single-engine short-take-off and vertical-landing tactical fighter configurations was investigated. These concepts involved blocking (or partially blocking) tailpipe flow to the rear (cruise) nozzle and diverting it through an opening to a ventral nozzle exit for vertical thrust. A set of variable angle vanes at the ventral nozzle exit were used to vary ventral nozzle thrust angle between 45 and 110 deg relative to the positive axial force direction. In the vertical flight mode the rear nozzle (or tailpipe flow to it) was completely blocked. In the transition flight mode flow in the tailpipe was split between the rear and ventral nozzles and the flow was vectored at both exits for aircraft control purposes through this flight regime. In the cruise flight mode the ventral nozzle was sealed and all flow exited through the rear nozzle.

  2. Physiological profile of fighters influences training organisation in combat sports: response to Del Vecchio, Hirata, and Franchini (2011).

    PubMed

    Paillard, Thierry

    2011-12-01

    The article by Del Vecchio, et al. (2011) provides relevant information to trainers about the effort-pause ratio during mixed martial arts matches. Taking into account the physiological profiles of fighters would increase interest in these findings.

  3. The Comanche and the Albatross: About Our Neck Was Hung

    DTIC Science & Technology

    2014-06-01

    aircraft .22 F-35 research, development, test, and evaluation funds are left intact for systems migration and maintenance of the aircraft already...and EPAWSS. c The F-15G (called EF-15E by Boeing) moves the EW systems from the EA-18G to the F-15E+. d New-build aircraft were priced for both...fighter fleet with the F-35A. This stealthy aircraft pos-sessed advanced technology and was no more expensive than the aircraft it was designed to

  4. Innovation in the Desert: 9th Air Force Tactical Aviation Logistics in Northwest Africa during World War II

    DTIC Science & Technology

    2017-06-09

    of strategic bombing . Douhet’s theory of airpower rested on four principles. First, the inherent strength of the defense on land would result in...Douhet envisioned the destruction of both the enemy’s airpower and economic capability to produce airpower through strategic bombing .6 While admitting...340-444. 3 fighter aircraft, Douhet believed that fighters were vulnerable to bombing and that their effectiveness after the initial stages of

  5. The C. elegans tailless/Tlx homolog nhr-67 regulates a stage-specific program of linker cell migration in male gonadogenesis.

    PubMed

    Kato, Mihoko; Sternberg, Paul W

    2009-12-01

    Cell migration is a common event during organogenesis, yet little is known about how migration is temporally coordinated with organ development. We are investigating stage-specific programs of cell migration using the linker cell (LC), a migratory cell crucial for male gonadogenesis of C. elegans. During the L3 and L4 larval stages of wild-type males, the LC undergoes changes in its position along the migratory route, in transcriptional regulation of the unc-5 netrin receptor and zmp-1 zinc matrix metalloprotease, and in cell morphology. We have identified the tailless homolog nhr-67 as a cell-autonomous, stage-specific regulator of timing in LC migration programs. In nhr-67-deficient animals, each of the L3 and L4 stage changes is either severely delayed or never occurs, yet LC development before the early L3 stage or after the mid-L4 stage occurs with normal timing. We propose that there is a basal migration program utilized throughout LC migration that is modified by stage-specific regulators such as nhr-67.

  6. V/STOL concepts in the United States: Past, present, and future

    NASA Technical Reports Server (NTRS)

    Nelms, W. P.; Anderson, S. B.

    1984-01-01

    Nonhelicopter types of V/STOL aircraft developed in the United States are reviewed, and some lessons learned from a selected number of concepts are highlighted. The AV-8B, which was developed by modifications to the British Harrier is the only current concept examined. Configurations proposed for the future subsonic, multimissing aircraft and the future supersonic fighter/attack aircraft are described. Emphasis is on these supersonic concepts.

  7. A New Paradigm for British Airpower

    DTIC Science & Technology

    2012-06-01

    airborne C2 and surveillance, SIGINT aircraft and complementary Remotely Piloted Air Systems. - Canceling the updated Nimrod Maritime Reconnaissance (MR...fighters and 6 Nimrod maritime patrol aircraft (http://en.wikipedia.org/wiki/Operation_Telic_order_of_battle ), post-SDSR the UK has 30 Tornado ground...the SDSR reflect these issues. Furthermore, operations in Libya involved aircraft capabilities, Sentinel and Nimrod R1, which will be removed and

  8. H-infinity based integrated flight-propulsion control design for a STOVL aircraft in transition flight

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Mattern, Duane L.; Bright, Michelle M.; Ouzts, Peter J.

    1990-01-01

    Results are presented from an application of H-infinity control design methodology to a centralized integrated flight/propulsion control (IFPC) system design for a supersonic Short Take-Off and Vertical Landing (STOVL) fighter aircraft in transition flight. The overall design methodology consists of a centralized IFPC controller design with controller partitioning. Only the feedback controller design portion of the methodology is addressed. Design and evaluation vehicle models are summarized, and insight is provided into formulating the H-infinity control problem such that it reflects the IFPC design objectives. The H-infinity controller is shown to provide decoupled command tracking for the design model. The controller order could be significantly reduced by modal residualization of the fast controller modes without any deterioration in performance. A discussion is presented of the areas in which the controller performance needs to be improved, and ways in which these improvements can be achieved within the framework of an H-infinity based linear control design.

  9. The Soviet Stealth Fighter: Check or Checkmate

    DTIC Science & Technology

    1988-04-01

    pp. 20-31. 25 11. Bussert, Jim and Paul Beaver. "Soviet Submarine Hull Coatings," Defense Electronics (August 1987), pp. 26-27. 12. Canan , James W...Aircraft (January 1987), pp. 50-59. 34. Vorobyov, Ivan , Major-General. "Formula for Victory," Soviet Military Review (November 1986), pp. 14-15. 35...34Stealth Somber Taking Shape," International Combat Aircraft (September 1987), pp. 27-31. Vozobyov, Ivan , Major-General. "New Weapons Require Sound

  10. Western Foreign Fighters in Syria: An Empirical Analysis of Recruitment and Mobilization Mechanisms

    DTIC Science & Technology

    2015-06-01

    Malet, Foreign Fighters, 5. 16 Ibid., 4–6. 17 See for example Ines von Behr, Anaïs Reding , Charlie Edwards, and Luke Gribbon, “Radicalization in the...summary see Ines von Behr, Anaïs Reding , Charlie Edwards, and Luke Gribbon, “Radicalization in the Digital Era: The Use of the Internet in 15 Cases of...12; <http://www.lexisnexis.com.libproxy.nps.edu/hottopics/lnacademic> [April 11, 2015]. 134 von Behr, Reding , Edwards, and Gribbon

  11. Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War Fighters

    DTIC Science & Technology

    2015-12-01

    1 AD_________________ AWARD NUMBER: W81XWH-08-2-0162 TITLE: Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War...Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War Fighters 5a. CONTRACT NUMBER 5b. GRANT NUMBER: W81XWH-08-2-0162 5c...Purpose: To demonstrate that 1) ultrasound guided foreign body removal (USFBR) is superior to conventional surgery in the cadaver model, 2) USFBR can be

  12. Famous head injuries of the first aerial war: deaths of the "Knights of the Air".

    PubMed

    Koul, Prateeka; Mau, Christine; Sabourin, Victor M; Gandhi, Chirag D; Prestigiacomo, Charles J

    2015-07-01

    World War I advanced the development of aviation from the concept of flight to the use of aircraft on the battlefield. Fighter planes advanced technologically as the war progressed. Fighter pilot aces Francesco Baracca and Manfred von Richthofen (the Red Baron) were two of the most famous pilots of this time period. These courageous fighter aces skillfully maneuvered their SPAD and Albatros planes, respectively, while battling enemies and scoring aerial victories that contributed to the course of the war. The media thrilled the public with their depictions of the heroic feats of fighter pilots such as Baracca and the Red Baron. Despite their aerial prowess, both pilots would eventually be shot down in combat. Although the accounts of their deaths are debated, it is undeniable that both were victims of traumatic head injury.

  13. Trampoline exercise vs. strength training to reduce neck strain in fighter pilots.

    PubMed

    Sovelius, Roope; Oksa, Juha; Rintala, Harri; Huhtala, Heini; Ylinen, Jari; Siitonen, Simo

    2006-01-01

    Fighter pilots' muscular strength and endurance are subjected to very high demands. Pilots' fatigued muscles are at higher risk for injuries. The purpose of this study was to compare the effects of two different training methods in reducing muscular loading during in-flight and cervical loading testing (CLT). There were 16 volunteer Finnish Air Force cadets who were divided into 2 groups: a strength training group (STG) and a trampoline training group (TTG). During the 6-wk training period, the STG performed dynamic flexion and extension and isometric rotation exercises, and the TTG performed trampoline bouncing exercises. During in-flight and CLT, muscle strain from the sternocleidomastoid, cervical erector spinae, trapezius, and thoracic erector spinae muscles was recorded with EMG. In-flight muscle strain in the STG after the training period decreased in the sternocleidomastoid 50%, cervical erector spinae 3%, trapezius 4%, and thoracic erector spinae 8%. In the TTG, the decrease was 41%, 30%, 20%, and 6%, respectively. In CLT, the results were similar. After a 3-mo follow-up period with intensive high +Gz flying, EMG during CLT was still lower than in baseline measurements. Both training methods were found to be effective in reducing muscle strain during in-flight and CLT, especially in the cervical muscles. There was no statistically significant difference between the training groups. Introduced exercises expand muscles' capacities in different ways and the authors recommend both strength and trampoline training programs to be included in fighter pilots' physical education programs.

  14. A study of prediction methods for the high angle-of-attack aerodynamics of straight wings and fighter aircraft

    NASA Technical Reports Server (NTRS)

    Mcmillan, O. J.; Mendenhall, M. R.; Perkins, S. C., Jr.

    1984-01-01

    Work is described dealing with two areas which are dominated by the nonlinear effects of vortex flows. The first area concerns the stall/spin characteristics of a general aviation wing with a modified leading edge. The second area concerns the high-angle-of-attack characteristics of high performance military aircraft. For each area, the governing phenomena are described as identified with the aid of existing experimental data. Existing analytical methods are reviewed, and the most promising method for each area used to perform some preliminary calculations. Based on these results, the strengths and weaknesses of the methods are defined, and research programs recommended to improve the methods as a result of better understanding of the flow mechanisms involved.

  15. Rhabdomyolysis and acute kidney injury in the injured war fighter.

    PubMed

    Elterman, Joel; Zonies, David; Stewart, Ian; Fang, Raymond; Schreiber, Martin

    2015-10-01

    Rhabdomyolysis is a recognized complication of traumatic injury. The correlation of an elevated creatine kinase (CK) level and the development of acute kidney injury (AKI) has been studied in the civilian population. We sought to review the prevalence of rhabdomyolysis in injured war fighters and determine if peak CK levels correlate with AKI. This is a retrospective cohort study of patients admitted at a US military treatment facility from January to November 2010. Inclusion criteria were active duty patients transported after explosive, penetrating, or blunt injury. Patients with burns or non-trauma-related admissions were excluded. Rhabdomyolysis was defined as a CK level greater than 5,000 U/L. AKI was defined using the Kidney Disease: Improving Global Outcomes classification. Mann-Whitney U-tests were used to determine the significance for continuous data. Correlations were determined using Spearman's ρ. Significance was set at p < 0.05. Of the 318 patients included in our analysis, 310 (98%) were male, and the median age was 24 years (21-28 years). Blast was the predominant mechanism of injury (71%), with a median Injury Severity Score (ISS) of 22 (16-29). Rhabdomyolysis developed in 79 patients (24.8%). The median peak CK for all patients was 4,178 U/L and ranged from 208 U/L to 120,000 U/L. Stage 1, 2, and 3 AKI developed in 56 (17.6%), 3 (0.9%), and 7 (2.2%) patients, respectively. There was a weak but statistically significant correlation between peak CK and AKI (r = 0.26, p < 0.05). Elevated peak CK levels in the injured war fighter are weakly associated with the development of AKI but are not predictive. The development of clinical practice guidelines would help standardize treatment for rhabdomyolysis in combat casualties and would allow for standardized comparisons in future work. Epidemiologic/prognostic study, level III.

  16. Historic Properties Report: Stratford Army Engine Plant, Connecticut.

    DTIC Science & Technology

    1984-07-01

    aircraft, Pan American began flights to Argentina, Hawaii, and New Zealand , and by August 1934 the Sikorsky S-42 airplane had set world records for...384;or a lengthy discussion of the Corsair , see William Green, Famous Fighters of the Second World War (Garden City, New York: Doubleday), pp. 79-92...manufacture the Corsair fighter plane. Presently, the Avco Lycoming Division uses the facility to develop and manufacture gas turbine engines. There are

  17. Eunuchs as better fighters?

    NASA Astrophysics Data System (ADS)

    Kralj-Fišer, Simona; Kuntner, Matjaž

    2012-02-01

    Male-male competition for females can significantly affect a male's reproductive success and hence his fitness. Game theory predicts that an individual should avoid fighting when its future reproductive potential is high, but should fight forcefully when its future reproductive potential is insignificant. When mates are scarce, extreme competition and fatal fighting is expected. We recently showed that Nephilengys malabarensis eunuchs, i.e. sterile spider males that lost their genitals during copulation, become more aggressive during male-male contests. Here, we add crucial comparative data by exploring eunuch fighting behaviour in Nephilengys livida from Madagascar, specifically by testing the `better fighter hypotheses' in a laboratory setting. Similar to N. malabarensis, N. livida copulations resulted in total male castration with the severed palp plugging the female genitals in 70.83% cases, which mostly (63.63%) prevented subsequent copulations. Unexpectedly, however, N. livida eunuchs exhibited lower aggressiveness than virgin males. We interpret these results in the light of different mating biology between the so far studied species known for the eunuch phenomenon, which might reflect differing plug effectiveness due to variation in genital anatomy in N. livida, N. malabarensis and Herennia multipuncta. However, detected differences in aggressive behaviour of N. livida versus N. malabarensis eunuchs might also be explained by the species' ecology, with lower population densities resulting in a relaxed male-male competition making excessive aggression and mate guarding redundant. This study thus questions the generality of overt aggressiveness in mated males with no reproductive value, and highlights the importance of understanding the natural history of species in the question.

  18. Wind-tunnel free-flight investigation of a supersonic persistence fighter

    NASA Technical Reports Server (NTRS)

    Hahne, David E.; Wendel, Thomas R.; Boland, Joseph R.

    1993-01-01

    Wind-tunnel free-flight tests have been conducted in the Langley 30- by 60-Foot Wind Tunnel to examine the high-angle-of-attack stability and control characteristics and control law design of a supersonic persistence fighter (SSPF) at 1 g flight conditions. In addition to conventional control surfaces, the SSPF incorporated deflectable wingtips (tiperons) and pitch and yaw thrust vectoring. A direct eigenstructure assignment technique was used to design control laws to provide good flying characteristics well into the poststall angle-of-attack region. Free-flight tests indicated that it was possible to blend effectively conventional and unconventional control surfaces to achieve good flying characteristics well into the poststall angle-of-attack region.

  19. JPRS Report, Soviet Union, Aviation & Cosmonautics, No. 5, May 1988

    DTIC Science & Technology

    1988-10-28

    about the air combat over the beach on the Bay of Pigs and about the pilots who in 1961, during the aggression launched by hirelings of U.S...number of aircraft. Attack aircraft (the principal strike component) include nuclear-weapons carrying A-6E Intruder and A-7E Corsair attack aircraft...based air and the adoption of new, modern combat aircraft. In particular, lightweight A-7E Corsair attack planes and F-4S Phan- tom II fighters are

  20. Is the F-35B the Right Fit for the MAGTF?

    DTIC Science & Technology

    2012-05-01

    F-35C Lightning II, consolidating three separate models of tactical aircraft into a fifth generation strike fighter. The F-35 provides "Day One...current replacement solution for the Marine Corps is the F-35B and F-35C Lightning II, consolidating three separate models of tactical aircraft into a...66.9 million. This aircraft has been operationally tested and is a familiar model of aircraft to the Marine Corps (see Appendix E). The F/A-18E or F

  1. An Apparatus for Varying Effective Dihedral in Flight with Application to a Study of Tolerable Dihedral on a Conventional Fighter Airplane

    NASA Technical Reports Server (NTRS)

    Kauffman, William M; Liddell, Charles J , Jr; Smith, Allan; Van Dyke, Rudolph D , Jr

    1949-01-01

    An apparatus for varying effective dihedral in flight by means of servo actuation of the ailerons in response to sideslip angle is described. The results of brief flight tests of the apparatus on a conventional fighter airplane are presented and discussed. The apparatus is shown to have satisfactory simulated a wide range of effective dihedral under static and dynamic conditions. The effects of a small amount of servo lag are shown to be measurable when the apparatus is simulating small negative values of dihedral. However, these effects were not considered by the pilots to give the airplane an artificial feel. The results of an investigation employing the apparatus to determine the tolerable (safe for normal fighter operation) range of effective dihedral on the test airplane are presented.

  2. Noise-immune multisensor transduction of speech

    NASA Astrophysics Data System (ADS)

    Viswanathan, Vishu R.; Henry, Claudia M.; Derr, Alan G.; Roucos, Salim; Schwartz, Richard M.

    1986-08-01

    Two types of configurations of multiple sensors were developed, tested and evaluated in speech recognition application for robust performance in high levels of acoustic background noise: One type combines the individual sensor signals to provide a single speech signal input, and the other provides several parallel inputs. For single-input systems, several configurations of multiple sensors were developed and tested. Results from formal speech intelligibility and quality tests in simulated fighter aircraft cockpit noise show that each of the two-sensor configurations tested outperforms the constituent individual sensors in high noise. Also presented are results comparing the performance of two-sensor configurations and individual sensors in speaker-dependent, isolated-word speech recognition tests performed using a commercial recognizer (Verbex 4000) in simulated fighter aircraft cockpit noise.

  3. An assessment of viscous effects in computational simulation of benign and burst vortex flows on generic fighter wind-tunnel models using TEAM code

    NASA Technical Reports Server (NTRS)

    Kinard, Tim A.; Harris, Brenda W.; Raj, Pradeep

    1995-01-01

    Vortex flows on a twin-tail and a single-tail modular transonic vortex interaction (MTVI) model, representative of a generic fighter configuration, are computationally simulated in this study using the Three-dimensional Euler/Navier-Stokes Aerodynamic Method (TEAM). The primary objective is to provide an assessment of viscous effects on benign (10 deg angle of attack) and burst (35 deg angle of attack) vortex flow solutions. This study was conducted in support of a NASA project aimed at assessing the viability of using Euler technology to predict aerodynamic characteristics of aircraft configurations at moderate-to-high angles of attack in a preliminary design environment. The TEAM code solves the Euler and Reynolds-average Navier-Stokes equations on patched multiblock structured grids. Its algorithm is based on a cell-centered finite-volume formulation with multistage time-stepping scheme. Viscous effects are assessed by comparing the computed inviscid and viscous solutions with each other and experimental data. Also, results of Euler solution sensitivity to grid density and numerical dissipation are presented for the twin-tail model. The results show that proper accounting of viscous effects is necessary for detailed design and optimization but Euler solutions can provide meaningful guidelines for preliminary design of flight vehicles which exhibit vortex flows in parts of their flight envelope.

  4. The Shaped Charge Concept. Part 3. Applications of Shaped Charges

    DTIC Science & Technology

    1990-10-01

    discus.A in Part 2. The MISTEL ( mistletoe ) concept used a fighter aircraft mounted piggyback on the top of a large bomber aircraft The unmanned...Tech. Pub. 2158, p.12. March 1947. Coles, R., and P. L Rickson. ’ Mistletoe - The Deadly Parasite," Air Classics Ouarterly Re’ew. Vol. 4, No. 3, pp. 38

  5. Smart Power: The United States, Iran, and a Nuclear Deal

    DTIC Science & Technology

    2014-05-22

    fighter aircraft to the Arabian Peninsula.2 1Aljazeera, “Iranian fighters ’fired on US drone in Gulf’,” http://www.aljazeera.com /news/middleeast...declared the Anglo-Iranian Oil Company (AIOC) nationalized on May 1, and in return promised compensation . He set up the National Iranian Oil...Italy, Japan, and the United States. 23Bill, 16. 24William O. Beeman, The “Great Satan” vs. the “ Mad Mullahs (Westport, CT: Greenwood Publishing

  6. Viper NHEXS Program: A Viper Pilot Neck Health & Conditioning Guide

    DTIC Science & Technology

    2012-11-01

    recommended in this manual. The Neck vs. Gs Problem At least one acute neck pain episode is reported to occur in an estimated 85% of all pilots flying...high-performance fighter type aircraft, with the yearly prevalence of neck-related pain for all pilots at 56% [1]. Vandebeek reported over 50% of...72% of fighter pilots experience neck pain in relation to flying, while 35% experience some low back pain . The reported average G level for acute

  7. Immunity-based detection, identification, and evaluation of aircraft sub-system failures

    NASA Astrophysics Data System (ADS)

    Moncayo, Hever Y.

    This thesis describes the design, development, and flight-simulation testing of an integrated Artificial Immune System (AIS) for detection, identification, and evaluation of a wide variety of sensor, actuator, propulsion, and structural failures/damages including the prediction of the achievable states and other limitations on performance and handling qualities. The AIS scheme achieves high detection rate and low number of false alarms for all the failure categories considered. Data collected using a motion-based flight simulator are used to define the self for an extended sub-region of the flight envelope. The NASA IFCS F-15 research aircraft model is used and represents a supersonic fighter which include model following adaptive control laws based on non-linear dynamic inversion and artificial neural network augmentation. The flight simulation tests are designed to analyze and demonstrate the performance of the immunity-based aircraft failure detection, identification and evaluation (FDIE) scheme. A general robustness analysis is also presented by determining the achievable limits for a desired performance in the presence of atmospheric perturbations. For the purpose of this work, the integrated AIS scheme is implemented based on three main components. The first component performs the detection when one of the considered failures is present in the system. The second component consists in the identification of the failure category and the classification according to the failed element. During the third phase a general evaluation of the failure is performed with the estimation of the magnitude/severity of the failure and the prediction of its effect on reducing the flight envelope of the aircraft system. Solutions and alternatives to specific design issues of the AIS scheme, such as data clustering and empty space optimization, data fusion and duplication removal, definition of features, dimensionality reduction, and selection of cluster/detector shape are also

  8. Design of a V/STOL propulsion system for a large-scale fighter model

    NASA Technical Reports Server (NTRS)

    Willis, W. S.

    1981-01-01

    Modifications were made to the existing Large-Scale STOL fighter model to simulate a V/STOL configuration. Modifications include the substitutions of two dimensional lift/cruise exhaust nozzles in the nacelles, and the addition of a third J97 engine in the fuselage to suppy a remote exhaust nozzle simulating a Remote Augmented Lift System. A preliminary design of the inlet and exhaust ducting for the third engine was developed and a detailed design was completed of the hot exhaust ducting and remote nozzle.

  9. High angle of attack flying qualities criteria for longitudinal rate command systems

    NASA Technical Reports Server (NTRS)

    Wilson, David J.; Citurs, Kevin D.; Davidson, John B.

    1994-01-01

    This study was designed to investigate flying qualities requirements of alternate pitch command systems for fighter aircraft at high angle of attack. Flying qualities design guidelines have already been developed for angle of attack command systems at 30, 45, and 60 degrees angle of attack, so this research fills a similar need for rate command systems. Flying qualities tasks that require post-stall maneuvering were tested during piloted simulations in the McDonnell Douglas Aerospace Manned Air Combat Simulation facility. A generic fighter aircraft model was used to test angle of attack rate and pitch rate command systems for longitudinal gross acquisition and tracking tasks at high angle of attack. A wide range of longitudinal dynamic variations were tested at 30, 45, and 60 degrees angle of attack. Pilot comments, Cooper-Harper ratings, and pilot induced oscillation ratings were taken from five pilots from NASA, USN, CAF, and McDonnell Douglas Aerospace. This data was used to form longitudinal design guidelines for rate command systems at high angle of attack. These criteria provide control law design guidance for fighter aircraft at high angle of attack, low speed flight conditions. Additional time history analyses were conducted using the longitudinal gross acquisition data to look at potential agility measures of merit and correlate agility usage to flying qualities boundaries. This paper presents an overview of this research.

  10. Experimental and analytical investigations to improve low-speed performance and stability and control characteristics of supersonic cruise fighter vehicles

    NASA Technical Reports Server (NTRS)

    Graham, A. B.

    1977-01-01

    Small- and large-scale models of supersonic cruise fighter vehicles were used to determine the effectiveness of airframe/propulsion integration concepts for improved low-speed performance and stability and control characteristics. Computer programs were used for engine/airframe sizing studies to yield optimum vehicle performance.

  11. Pushing through evolution? Incidence and fight records of left-oriented fighters in professional boxing history.

    PubMed

    Loffing, Florian; Hagemann, Norbert

    2015-05-01

    The fighting hypothesis proposes that left-oriented athletes enjoy a negative frequency-dependent advantage in combat sports such as boxing. Supporting evidence, however, is restricted to cross-sectional frequency data from small samples. Here, we examined the incidence and fight records of 2,403 left- and right-oriented fighters who were listed in the annual ratings of professional boxing from 1924 to 2012. Unexpectedly, left-oriented boxers were overrepresented in no more than 7 of the 89 years considered, their percentages varied up to 30% and increased over the entire period, and frequencies varied substantially between weight divisions. In support of the fighting hypothesis, lose-win ratios indicated larger fighting strength in left- compared to right-oriented boxers, which, however, was not reflected in different proportions of wins and losses by knockout. Our findings are partly consistent with an assumed left-oriented fighters' advantage in combat sports. Such advantage could be explained by negative frequency-dependent selection mechanisms; however, our study also revealed potential limits of the fighting hypothesis such that alternative explanations cannot be fully excluded. We propose that interference by factors not related to performance could also limit the suitability of data from elite sporting competition for testing evolutionary models of human handedness.

  12. A comparison of theoretical and experimental pressure distributions for two advanced fighter wings

    NASA Technical Reports Server (NTRS)

    Haney, H. P.; Hicks, R. M.

    1981-01-01

    A comparison was made between experimental pressure distributions measured during testing of the Vought A-7 fighter and the theoretical predictions of four transonic potential flow codes. Isolated wind and three wing-body codes were used for comparison. All comparisons are for transonic Mach numbers and include both attached and separate flows. In general, the wing-body codes gave better agreement with the experiment than did the isolated wing code but, because of the greater complexity of the geometry, were found to be considerably more expensive and less reliable.

  13. Effectiveness of brief VR treatment for PTSD in war-fighters: a case study.

    PubMed

    Miyahira, Sarah D; Folen, Raymond A; Hoffman, Hunter G; Garcia-Palacios, Azucena; Schaper, Kim M

    2010-01-01

    War-fighters exposed to combat are at high risk for developing posttraumatic stress disorder (PTSD), a complex and challenging condition to treat. Cognitive behavioral therapies (CBT) have been empirically validated as effective treatments for PTSD resulting from sexual assault, vehicular accidents, and disasters. Exposure, imaginal or in vivo, to the traumatic event is a central component of successful CBT treatment. Early studies indicate that CBT with brief virtual reality exposure (VRE) is beneficial in treating PTSD. The case study examined the effectiveness of brief VRE in treating combat-related PTSD.

  14. Measurement and Analysis of Wing and Tail Buffeting Loads on a Fighter Airplane

    NASA Technical Reports Server (NTRS)

    Huston, Wilber B; Skopinski, T H

    1955-01-01

    The buffeting loads measured on the wing and tail of a fighter airplane during 194 maneuvers are given in tabular form, along with the associated flight conditions. Measurements were made at altitudes of 30,000 to 10,000 feet and at speeds up to a Mach number of 0.8. Least-squares methods have been used for a preliminary analysis of the data. The agreement between the results of this analysis and the loads measured in stalls is sufficiently good to suggest the examination of the buffeting of other airplanes on the same basis.

  15. Subsonic characteristics of a twin-jet swept-wing fighter model with maneuvering devices

    NASA Technical Reports Server (NTRS)

    Ray, E. J.; Hollingsworth, E. G.

    1973-01-01

    An investigation has been conducted at Mach numbers ranging from 0.06 to 0.94 to determine the effects of various combinations of leading-edge slat devices on the static aerodynamic characteristics of a twin-jet swept-wing fighter model. The study also included a determination of the effects of wing leading-edge droop, trailing-edge chord-extensions, wing fences, and wing-planform and camber modifications. The angle-of-attack range generally extended from about minus 2 deg to 24 deg and the sideslip angles ranged from about minus 6 deg to 13 deg.

  16. Redirected Radicals: Understanding the Risk of Altered Targeting Trajectories Among ISIL’s Aspiring Foreign Fighters

    DTIC Science & Technology

    2016-09-01

    severe. Chapter III begins the first part of the comparative case study analysis by focusing on Canada’s current foreign fighter issues, propaganda...violence in their home countries. Through an extensive comparative case study analysis of recent ISIL-related violent incidents and plots in the United...overseas, decided instead to alter their targeting trajectory and commit violence in their home countries. Through an extensive comparative case study

  17. Bringing Cost-Wise Readiness to the Deckplates of a Strike Fighter Squadron Using the Balanced Scorecard

    DTIC Science & Technology

    2013-12-01

    equity employed). Customer measures, such as customer satisfaction , are intended to measure the company’s performance from the customer’s perspective...link between a non-financial measure and a firm’s financial performance. For example, one could meet objectives relating to customer satisfaction ... customer satisfaction . Who then is the customer of a strike fighter squadron? Kaplan and Norton (2004) write extensively about 61 the value

  18. Then and Now: Comparing the Flow of Foreign Fighters to AQI and the Islamic State

    DTIC Science & Technology

    2016-12-01

    State during separate blocks of time . Second, it provides insight into the local travel and flow of foreign fighters across time , and the mobilization...who joined the Islamic State during that latter time period also traveled alone more frequently. When they didn’t travel alone, they arrived in...arriving at the caliphate are larger than they were during the time period covered by the Sinjar records. A couple of cases of group travel to Syria

  19. Wave drag as the objective function in transonic fighter wing optimization

    NASA Technical Reports Server (NTRS)

    Phillips, P. S.

    1984-01-01

    The original computational method for determining wave drag in a three dimensional transonic analysis method was replaced by a wave drag formula based on the loss in momentum across an isentropic shock. This formula was used as the objective function in a numerical optimization procedure to reduce the wave drag of a fighter wing at transonic maneuver conditions. The optimization procedure minimized wave drag through modifications to the wing section contours defined by a wing profile shape function. A significant reduction in wave drag was achieved while maintaining a high lift coefficient. Comparisons of the pressure distributions for the initial and optimized wing geometries showed significant reductions in the leading-edge peaks and shock strength across the span.

  20. A parametric study of planform and aeroelastic effects on aerodynamic center, alpha- and q-stability derivatives

    NASA Technical Reports Server (NTRS)

    Roskam, J.; Lan, C.

    1973-01-01

    Summarized are the aerodynamic center, alpha and q- aeroelastic effects on fighter-type aircraft in the 18,700 N gross range. The results indicate that with proper tailoring of planform (fixed or variable sweep), stiffner and elastic axis location it is possible to minimize trim requirements between selected extreme conditions. The inertial effects were found to be small for this class of aircraft.

  1. The C. elegans Tailless/TLX transcription factor nhr-67 controls neuronal identity and left/right asymmetric fate diversification.

    PubMed

    Sarin, Sumeet; Antonio, Celia; Tursun, Baris; Hobert, Oliver

    2009-09-01

    An understanding of the molecular mechanisms of cell fate determination in the nervous system requires the elucidation of transcriptional regulatory programs that ultimately control neuron-type-specific gene expression profiles. We show here that the C. elegans Tailless/TLX-type, orphan nuclear receptor NHR-67 acts at several distinct steps to determine the identity and subsequent left/right (L/R) asymmetric subtype diversification of a class of gustatory neurons, the ASE neurons. nhr-67 controls several broad aspects of sensory neuron development and, in addition, triggers the expression of a sensory neuron-type-specific selector gene, che-1, which encodes a zinc-finger transcription factor. Subsequent to its induction of overall ASE fate, nhr-67 diversifies the fate of the two ASE neurons ASEL and ASER across the L/R axis by promoting ASER and inhibiting ASEL fate. This function is achieved through direct expression activation by nhr-67 of the Nkx6-type homeobox gene cog-1, an inducer of ASER fate, that is inhibited in ASEL through the miRNA lsy-6. Besides controlling bilateral and asymmetric aspects of ASE development, nhr-67 is also required for many other neurons of diverse lineage history and function to appropriately differentiate, illustrating the broad and diverse use of this type of transcription factor in neuronal development.

  2. Samarium Cobalt (SmCo) Generator/Engine Integration Study

    DTIC Science & Technology

    1980-04-01

    110o1110 (Cole Ms -W~ Daiwa. to* J11 tuo.in Wfi wee -004"ni Aircraft Generator/starter Samarium Cobalt Turbine Engine , Feasibility Secondary Power...integration into the main rotor system of typical aircraft gas turbine engines . A major objective is the definition of the engine interface for such... Engine The F404 is a low bypass, augmented turbofan Pngine developed for application in advanced fighter aircraft (F-18). This type of engine benefits most

  3. Interaction of Aircraft Wakes From Laterally Spaced Aircraft

    NASA Technical Reports Server (NTRS)

    Proctor, Fred H.

    2009-01-01

    Large Eddy Simulations are used to examine wake interactions from aircraft on closely spaced parallel paths. Two sets of experiments are conducted, with the first set examining wake interactions out of ground effect (OGE) and the second set for in ground effect (IGE). The initial wake field for each aircraft represents a rolled-up wake vortex pair generated by a B-747. Parametric sets include wake interactions from aircraft pairs with lateral separations of 400, 500, 600, and 750 ft. The simulation of a wake from a single aircraft is used as baseline. The study shows that wake vortices from either a pair or a formation of B-747 s that fly with very close lateral spacing, last longer than those from an isolated B-747. For OGE, the inner vortices between the pair of aircraft, ascend, link and quickly dissipate, leaving the outer vortices to decay and descend slowly. For the IGE scenario, the inner vortices ascend and last longer, while the outer vortices decay from ground interaction at a rate similar to that expected from an isolated aircraft. Both OGE and IGE scenarios produce longer-lasting wakes for aircraft with separations less than 600 ft. The results are significant because concepts to increase airport capacity have been proposed that assume either aircraft formations and/or aircraft pairs landing on very closely spaced runways.

  4. An Examination of Brazil and the United States as Potential Partners in a Joint Supersonic Military Fighter Aircraft Codevelopment and Production Program.

    DTIC Science & Technology

    1986-09-01

    Brazilian-American Chamber of Commerce Mr. Frank J. Devine, Executive Director Embraer, Empresa Brasileira De Aeronautica Mr. Salo Roth Vice President...Throughout this study the following assumptions have been made. First, it is assumed that the reader has a basic familiarity with aircraft. Therefore...of the 5 1 weapons acquisition process. Third, the assumption is made that most readers are familiar with U.S. procedures involving the sale of

  5. Defense.gov Special Report: Operation Odyssey Dawn

    Science.gov Websites

    Supports Coalition Operations Over Libya Marines Rescue Downed Pilot After Fighter Jet Crashes in Libya Corps Aircraft Strike Libya U.S. Naval Forces Prepare No-Fly Zone Coalition Launches Operations, Set Up

  6. In-flight hypoxia incidents in military aircraft: causes and implications for training.

    PubMed

    Cable, Gordon G

    2003-02-01

    Hypoxia has long been recognized as a significant physiological threat at altitude. Aircrew have traditionally been trained to recognize the symptoms of hypoxia using hypobaric chamber training at simulated altitudes of 25,000 ft or more. The aim of this study was to analyze incidents of hypoxia reported to the Directorate of Flying Safety of the Australian Defence Force (DFS-ADF) for the period 1990-2001, as no previous analysis of these incidents has been undertaken. The data will be useful in planning future training strategies for aircrew in aviation physiology. A search was requested of the DFS-ADF database, for all Aircraft Safety Occurrence Reports (ASOR) listing hypoxia as a factor. These cases were reviewed and the following data analyzed: aircraft type, number of persons on board (POB), number of hypoxic POB, any fatalities, whether the victims were trained or untrained as aircrew, if the symptoms were recognized as hypoxia, symptoms experienced, the altitude at which the incident occurred, and the likely cause. During the period studied. 27 reports of hypoxia were filed, involving 29 aircrew. In only two cases was consciousness lost, and one of these resulted in a fatality. Most incidents (85.1%) occurred in fighter or training aircraft with aircrew who use oxygen equipment routinely. The majority of symptoms occurred between 10,000 and 19,000 ft. The most common cause of hypoxia (63%) in these aircraft was the failure of the mask or regulator, or a mask leak. Rapid accidental decompression did not feature as a cause of hypoxia. Symptoms were subtle and often involved cognitive impairment or light-headedness. The vast majority (75.8%) of these episodes were recognized by the aircrew themselves, reinforcing the importance and benefit of hypoxia training. This study confirms the importance and effectiveness of hypoxia training for aircrew. Hypoxia incidents occur most commonly at altitudes less than 19,000 ft. This should be emphasized to aircrew, whose

  7. From Les Chevaliers du Ciel to Steely-Eyed Killers: Intersecting Influences of Hollywood and Reality on the Romanticization of Fighter Pilots

    DTIC Science & Technology

    2013-12-01

    is critical to establishing his heroic identity . Authority Issues: Whether portrayed via confrontation (e.g., Fighter Squadron, The Dawn Patrol...traits throughout the subject’s cinema history has solidified the archetype into the public’s subconscious. Some combination of youthfulness

  8. Cross-sectional study of neck pain and cervical sagittal alignment in air force pilots.

    PubMed

    Moon, Bong Ju; Choi, Kyong Ho; Yun, Chul; Ha, Yoon

    2015-05-01

    There is a high prevalence of neck pain in air force pilots; however, the causes are not clear and are considered work-related. Kyphotic changes in the cervical spine have been known to cause neck pain. In this study, we investigated the association between neck pain and cervical kyphosis in air force pilots. This is a cross-sectional study of 63 Republic of South Korea Air Force pilots. We examined the C2-7 absolute rotation angle (ARA) using the posterior tangent method and other radiologic parameters on whole spine lateral radiographs. We divided the participants into a neck pain group (N = 32) and no neck pain group (N = 31), and subsequently analyzed the difference in radiographic parameters and clinical data between the two groups. There were no significant differences found in age, body mass index, total flight time, or aerobic or anaerobic exercise between the neck pain and control groups. The fighter pilots had higher 1-yr prevalence of neck pain than nonfighter pilots (84.4% vs. 15.6%). The lower C2-7 ARA (OR = 0.91, 95% CI 0.846, 0.979) and fighter type aircrafts (OR = 3.93, 95% CI 1.104, 13.989) were associated with neck pain. Fighter pilots experienced neck pain more frequently than the nonfighter pilots. Those fighter pilots suffering from neck pain were shown to have more kyphotic changes in the cervical spine than control pilots through evaluation of whole spine lateral radiographs using the posterior tangent method. These key findings suggest that the forces involved in flying a fighter type aircraft may affect cervical alignment and neck pain.

  9. Full-scale wind-tunnel tests of high-lift system modifications on a carrier based fighter aircraft

    NASA Technical Reports Server (NTRS)

    Meyn, Larry A.; Zell, Peter T.; Hagan, John L.; Schoch, David

    1993-01-01

    Modifications to the high-lift system of a full-scale F/A-I8A were tested in the 80- by 120-Foot Wind Tunnel of the National Full-Scale Aerodynamics Complex at the NASA Ames Research Center in Moffett Field, California. The objective was to measure the effect of simple modifications on the aerodynamic performance of the high-lift system. The modifications included the placement of a straight fairing in the shroud cove above the trailing-edge flap and the addition of seals to prevent air leakage through the hinge lines of the leading-edge flap, the trailing-edge shroud, and the wing fold. The test was carried out on an actual F/A-18A with it's flaps deployed in the landing approach configuration. The angle of attack ranged from 0 to 16 degrees and the wind speed was 100 knots. At an angle of attack of 8 degrees, the trimmed lift coefficient was improved by 0.09 with all wing seals in place. This corresponds to a reduction in the approach speed for the F/A-I8A of about 5 knots. The seal along the wing fold hinge, a feature present on many naval aircraft, provided one third of the total increment in trimmed lift. A comparison of the full-scale wind-tunnel results with those obtained from flight test is also presented.

  10. Aircraft

    DOEpatents

    Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

    1998-01-01

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

  11. Aircraft

    DOEpatents

    Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

    1998-09-22

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

  12. Optimal Pitch Thrust-Vector Angle and Benefits for all Flight Regimes

    NASA Technical Reports Server (NTRS)

    Gilyard, Glenn B.; Bolonkin, Alexander

    2000-01-01

    The NASA Dryden Flight Research Center is exploring the optimum thrust-vector angle on aircraft. Simple aerodynamic performance models for various phases of aircraft flight are developed and optimization equations and algorithms are presented in this report. Results of optimal angles of thrust vectors and associated benefits for various flight regimes of aircraft (takeoff, climb, cruise, descent, final approach, and landing) are given. Results for a typical wide-body transport aircraft are also given. The benefits accruable for this class of aircraft are small, but the technique can be applied to other conventionally configured aircraft. The lower L/D aerodynamic characteristics of fighters generally would produce larger benefits than those produced for transport aircraft.

  13. Numerical simulation of a powered-lift landing, tracking flow features using overset grids, and simulation of high lift devices on a fighter-lift-and-control wing

    NASA Technical Reports Server (NTRS)

    Chawla, Kalpana

    1993-01-01

    Attached as appendices to this report are documents describing work performed on the simulation of a landing powered-lift delta wing, the tracking of flow features using overset grids, and the simulation of flaps on the Wright Patterson Lab's fighter-lift-and-control (FLAC) wing. Numerical simulation of a powered-lift landing includes the computation of flow about a delta wing at four fixed heights as well as a simulated landing, in which the delta wing descends toward the ground. Comparison of computed and experimental lift coefficients indicates that the simulations capture the qualitative trends in lift-loss encountered by thrust-vectoring aircraft operating in ground effect. Power spectra of temporal variations of pressure indicate computed vortex shedding frequencies close to the jet exit are in the experimentally observed frequency range; the power spectra of pressure also provide insights into the mechanisms of lift oscillations. Also, a method for using overset grids to track dynamic flow features is described and the method is validated by tracking a moving shock and vortices shed behind a circular cylinder. Finally, Chimera gridding strategies were used to develop pressure coefficient contours for the FLAC wing for a Mach no. of 0.18 and Reynolds no. of 2.5 million.

  14. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Manufacture of new aircraft, aircraft... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  15. Evaluation of pressure and thermal data from a wind tunnel test of a large-scale, powered, STOL fighter model

    NASA Technical Reports Server (NTRS)

    Howell, G. A.; Crosthwait, E. L.; Witte, M. C.

    1981-01-01

    A STOL fighter model employing the vectored-engine-over wing concept was tested at low speeds in the NASA/Ames 40 by 80-foot wind tunnel. The model, approximately 0.75 scale of an operational fighter, was powered by two General Electric J-97 turbojet engines. Limited pressure and thermal instrumentation were provided to measure power effects (chordwise and spanwise blowing) and control-surface-deflection effects. An indepth study of the pressure and temperature data revealed many flow field features - the foremost being wing and canard leading-edge vortices. These vortices delineated regions of attached and separated flow, and their movements were often keys to an understanding of flow field changes caused by power and control-surface variations. Chordwise blowing increased wing lift and caused a modest aft shift in the center of pressure. The induced effects of chordwise blowing extended forward to the canard and significantly increased the canard lift when the surface was stalled. Spanwise blowing effectively enhanced the wing leading-edge vortex, thereby increasing lift and causing a forward shift in the center of pressure.

  16. MicroRNA-378 regulates neural stem cell proliferation and differentiation in vitro by modulating Tailless expression.

    PubMed

    Huang, Yanxia; Liu, Xiaoguai; Wang, Yaping

    2015-10-16

    Previous studies have suggested that microRNAs (miRNAs) play an important role in regulating neural stem cell (NSC) proliferation and differentiation. However, the precise role of miRNAs in NSC remains largely unexplored. In this study, we showed that miR-378 can target Tailless (TLX), a critical regulator of NSC, to regulate NSC proliferation and differentiation. By bioinformatic algorithms, miR-378 was found to have a predicted target site in the 3'-untranslated region of TLX, which was verified by a dual-luciferase reporter assay. The expression of miR-378 was increased during NSC differentiation and inversely correlated with TLX expression. qPCR and Western blot analysis also showed that miR-378 negatively regulated TLX mRNA and protein expression in neural stem cells (NSCs). Intriguingly, overexpression of miR-378 increased NSC differentiation and reduced NSC proliferation, whereas suppression of miR-378 led to decreased NSC differentiation and increased NSC proliferation. Moreover, the downstream targets of TLX, including p21, PTEN and Wnt/β-catenin were also found to be regulated by miR-378. Additionally, overexpression of TLX rescued the NSC proliferation deficiency induced by miR-378 overexpression and abolished miR-378-promoted NSC differentiation. Taken together, our data suggest that miR-378 is a novel miRNA that regulates NSC proliferation and differentiation via targeting TLX. Therefore, manipulating miR-378 in NSCs could be a novel strategy to develop novel interventions for the treatment of relevant neurological disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. QuickStrike ASOC Battlefield Simulation: Preparing the War Fighter to Win

    NASA Technical Reports Server (NTRS)

    Jones, Richard L.

    2010-01-01

    The QuickStrike ASOC (Air Support Operations Center) Battlefield Simulation fills a crucial gap in USAF and United Kingdom Close Air Support (CAS) and airspace manager training. The system now provides six squadrons with the capability to conduct total-mission training events whenever the personnel and time are available. When the 111th ASOC returned from their first deployment to Afghanistan they realized the training available prior to deployment was inadequate. They sought an organic training capability focused on the ASOC mission that was low cost, simple to use, adaptable, and available now. Using a commercial off-the-shelf simulation, they developed a complete training system by adapting the simulation to their training needs. Through more than two years of spiral development, incorporating lessons learned, the system has matured, and can now realistically replicate the Tactical Operations Center (TOC) in Kabul, Afghanistan, the TOC supporting the mission in Iraq, or can expand to support a major conflict scenario. The training system provides a collaborative workspace for the training audience and exercise control group via integrated software and workstations that can easily adapt to new mission reqUirements and TOC configurations. The system continues to mature. Based on inputs from the war fighter, new capabilities have been incorporated to add realism and simplify the scenario development process. The QuickStrike simulation can now import TBMCS Air Tasking Order air mission data and can provide air and ground tracks to a common operating picture; presented through either C2PC or JADOCS. This oranic capability to practice team processes and tasks and to conduct mission rehearsals proved its value in the 111 h ASOS's next deployment. The ease of scenario development and the simple to learn and intuitive gamelike interface enables the squadrons to develop and share scenarios incorporating lessons learned from every deployment. These war fighters have now

  18. Budget Options for National Defense

    DTIC Science & Technology

    2000-03-01

    Corps’s V -22 Aircraft 51 3-19-A Reduce Purchases of the Air Force’s F-22 Fighter 52 3-19-B Cancel Production of the...of 13 very quiet subma- rines by 2012, meeting the Joint Chiefs’ requirement. Option 3-18 Defer Purchases of the Marine Corps’s V -22 Aircraft...110 -658 -113 3,270 -2,285 RELATED CBO PUBLICATION: Moving the Marine Corps by Sea in the 1990s (Study), October 1989. The V -22 aircraft, which

  19. EC88-0052-4

    NASA Image and Video Library

    1988-03-29

    View of the left cockpit and pilot's seat of the F-111 MAW aircraft. Unlike most fighter aircraft of the time, the F-111 had side-by-side seating. The pilot sat on the left side, and the weapons systems officer on the right. Both had control sticks to fly the aircraft. The two yellow and black striped handles would be used in an emergency to eject the entire F-111 cockpit. The F-111 also did not have ejection seats, but used a capsule.

  20. Euler Technology Assessment for Preliminary Aircraft Design: Compressibility Predictions by Employing the Cartesian Unstructured Grid SPLITFLOW Code

    NASA Technical Reports Server (NTRS)

    Finley, Dennis B.; Karman, Steve L., Jr.

    1996-01-01

    The objective of the second phase of the Euler Technology Assessment program was to evaluate the ability of Euler computational fluid dynamics codes to predict compressible flow effects over a generic fighter wind tunnel model. This portion of the study was conducted by Lockheed Martin Tactical Aircraft Systems, using an in-house Cartesian-grid code called SPLITFLOW. The Cartesian grid technique offers several advantages, including ease of volume grid generation and reduced number of cells compared to other grid schemes. SPLITFLOW also includes grid adaption of the volume grid during the solution to resolve high-gradient regions. The SPLITFLOW code predictions of configuration forces and moments are shown to be adequate for preliminary design, including predictions of sideslip effects and the effects of geometry variations at low and high angles-of-attack. The transonic pressure prediction capabilities of SPLITFLOW are shown to be improved over subsonic comparisons. The time required to generate the results from initial surface data is on the order of several hours, including grid generation, which is compatible with the needs of the design environment.

  1. Memphis Belle and Crew Visit the Aircraft Engine Research Laboratory

    NASA Image and Video Library

    1943-07-21

    Captain Robert Morgan and the rest of the Memphis Belle crew arrive in Cleveland on a rainy July 7, 1943, for three-day publicity visit. This B–17 Flying Fortress had recently become the first U.S. bomber to complete 25 missions over Germany and France. The lack of long distance escort fighters made the feat even more remarkable. The Memphis Belle and its crew returned to the United States in June and were immediately thrown into a three-month-long war bond tour. While in Cleveland the crew toured the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory, the Cleveland Bomber Plant, and Thompson Products. In the evenings they were feted downtown by the Chamber of Commerce at the Hotel Cleveland. A local company brought Morgan’s family and his fiancé—the Memphis Belle’s inspiration—to Cleveland to participate in the activities. The bomber was on display to the public near the airport’s fenceline and stored in the NACA’s hangar overnight. Pictured in this photograph from left to right: Robert Hanson, Vincent Evans, Charles Leighton, NACA Manager Raymond Sharp, Robert Morgan, William Holliday of the Chamber of Commerce, Army Liaison Officer Colonel Edwin Page, Airport Commissioner Jack Berry, Cecil Scott, John Quinlan and James Verinis. Kneeling are Harold Loch, Casimer Nastal and Charles Wichell.

  2. Tailless Vectored Fighters Theory. Laboratory and Flight Tests, Including Vectorable Inlets/Nozzles and Tailless Flying Models vs. Pilot’s Tolerances Affecting Maximum Post-Stall Vectoring Agility.

    DTIC Science & Technology

    1991-07-01

    nose bodyj Top view of velocity probe PropllerRotating shaft ’V Generator Aerodynamic shape like a small elevator RPV’s attitude Irrespctiveduring...28 Part It: Maximizing Thrust-Vectoring Control Power and Agility Metrics ............ 29 Laboratory & Flight...8217Ideal Standards’ - Ba- ror maximizing PST-TV-aglilty/rIlght-control power , iI - Extracting new TV-potentials to further reduce any righter’s optical

  3. The Saudi-Iranian Rivalry and the Future of Middle East Security

    DTIC Science & Technology

    2011-12-01

    gain a variety of allies, Da- mascus established dramatically improved relations with Turkey prior to the Arab Spring, although these relations...air force, including F-16 fighter aircraft.162 The Iranian Air Force, which is based on older Russian /Soviet and Chinese aircraft, could never compete...liberal, dem- ocratic government. Nevertheless, the last chapter may not have been written in this story . The examples of Egypt, Tunisia, and Libya are

  4. Optimization of Turkish Air Force SAR Units Forward Deployment Points for a Central Based SAR Force Structure

    DTIC Science & Technology

    2015-03-26

    Turkish Airborne Early Warning and Control (AEW& C ) aircraft in the combat arena. He examines three combat scenarios Turkey might encounter to cover and...to limited SAR assets, constrained budgets, logistic- maintenance problems, and high risk level of military flights. In recent years, the Turkish Air...model, Set Covering Location Problem (SCLP), defines the minimum number of SAR DPs to cover all fighter aircraft training areas (TAs). The second

  5. Real-time data display for AFTI/F-16 flight testing

    NASA Technical Reports Server (NTRS)

    Harney, P. F.

    1982-01-01

    Advanced fighter technologies to improve air to air and air to surface weapon delivery and survivability is demonstrated. Real time monitoring of aircraft operation during flight testing is necessary not only for safety considerations but also for preliminary evaluation of flight test results. The complexity of the AFTI/F-16 aircraft requires an extensive capability to accomplish real time data goals; that capability and the resultant product are described.

  6. NATO’s Changing its Posture Against Russia from Assurance to Deterrence: Does it Matter

    DTIC Science & Technology

    2017-04-06

    the West, raising fears of a resurgent Russia intent on regaining its former dominance in Eastern Europe. Over the last two years, the North...to purchase 52 F-35 fighters, replace its submarine fleet, purchase new surveillance aircraft, upgrade tank units, and acquire new anti-aircraft...for an additional $2 billion to purchase armored personnel carriers, artillery, anti-tank weapons and air defense systems.19 NATO’s posture change

  7. Effect of protective filters on fire fighter respiratory health: field validation during prescribed burns.

    PubMed

    De Vos, Annemarie J B M; Cook, Angus; Devine, Brian; Thompson, Philip J; Weinstein, Philip

    2009-01-01

    Bushfire smoke contains a range of air toxics. To prevent inhalation of these toxics, fire fighters use respiratory equipment. Yet, little is known about the effectiveness of the equipment on the fire ground. Experimental trials in a smoke chamber demonstrated that, the particulate/organic vapor/formaldehyde (POVF) filter performed best under simulated conditions. This article reports on the field validation trials during prescribed burns in Western Australia. Sixty-seven career fire fighters from the Fire and Emergency Services Authority of Western Australia were allocated one of the three types of filters. Spirometry, oximetry, self-reported symptom, and personal air sampling data were collected before, during and after exposure to bushfire smoke from prescribed burns. Declines in FEV(1) and SaO(2) were demonstrated after 60 and 120 min exposure. A significant higher number of participants in the P filter group reported increases in respiratory symptoms after the exposure. Air sampling inside the respirators demonstrated formaldehyde levels significantly higher in the P filter group compared to the POV and the POVF filter group. The field validation trials during prescribed burns supported the findings from the controlled exposure trials in the smoke chamber. Testing the effectiveness of three types of different filters under bushfire smoke conditions in the field for up to 2 hr demonstrated that the P filter is ineffective in filtering out respiratory irritants. The performance of the POV and the POVF filter appears to be equally effective after 2 hr bushfire smoke exposure in the field.

  8. Procurement Practices for the Composite Armored Vehicle and Composite Affordability Initiative Programs

    DTIC Science & Technology

    1999-10-26

    The audit objective was to determine whether violations of procurement regulations occurred regarding procurement of selected components of the Army...Crusader vehicle and the Joint Strike Fighter aircraft. However, during the audit , we determined that the allegations involved the Army Composite

  9. Hexavalent chromium and isocyanate exposures during military aircraft painting under crossflow ventilation.

    PubMed

    Bennett, James S; Marlow, David A; Nourian, Fariba; Breay, James; Hammond, Duane

    2016-01-01

    Exposure control systems performance was investigated in an aircraft painting hangar. The ability of the ventilation system and respiratory protection program to limit worker exposures was examined through air sampling during painting of F/A-18C/D strike fighter aircraft, in four field surveys. Air velocities were measured across the supply filter, exhaust filter, and hangar midplane under crossflow ventilation. Air sampling conducted during painting process phases (wipe-down, primer spraying, and topcoat spraying) encompassed volatile organic compounds, total particulate matter, Cr[VI], metals, nitroethane, and hexamethylene diisocyanate, for two worker groups: sprayers and sprayer helpers ("hosemen"). One of six methyl ethyl ketone and two of six methyl isobutyl ketone samples exceeded the short term exposure limits of 300 and 75 ppm, with means 57 ppm and 63 ppm, respectively. All 12 Cr[VI] 8-hr time-weighted averages exceeded the recommended exposure limit of 1 µg/m3, 11 out of 12 exceeded the permissible exposure limit of 5 µg/m3, and 7 out of 12 exceeded the threshold limit value of 10 µg/m3, with means 38 µg/m3 for sprayers and 8.3 µg/m3 for hosemen. Hexamethylene diisocyanate means were 5.95 µg/m3 for sprayers and 0.645 µg/m3 for hosemen. Total reactive isocyanate group--the total of monomer and oligomer as NCO group mass--showed 6 of 15 personal samples exceeded the United Kingdom Health and Safety Executive workplace exposure limit of 20 µg/m3, with means 50.9 µg/m3 for sprayers and 7.29 µg/m3 for hosemen. Several exposure limits were exceeded, reinforcing continued use of personal protective equipment. The supply rate, 94.4 m3/s (200,000 cfm), produced a velocity of 8.58 m/s (157 fpm) at the supply filter, while the exhaust rate, 68.7 m3/s (146,000 cfm), drew 1.34 m/s (264 fpm) at the exhaust filter. Midway between supply and exhaust locations, the velocity was 0.528 m/s (104 fpm). Supply rate exceeding exhaust rate created re

  10. Reduction of structural loads using maneuver load control on the Advanced Fighter Technology Integration (AFTI)/F-111 mission adaptive wing

    NASA Technical Reports Server (NTRS)

    Thornton, Stephen V.

    1993-01-01

    A transonic fighter-bomber aircraft, having a swept supercritical wing with smooth variable-camber flaps was fitted with a maneuver load control (MLC) system that implements a technique to reduce the inboard bending moments in the wing by shifting the spanwise load distribution inboard as load factor increases. The technique modifies the spanwise camber distribution by automatically commanding flap position as a function of flap position, true airspeed, Mach number, dynamic pressure, normal acceleration, and wing sweep position. Flight test structural loads data were obtained for loads in both the wing box and the wing root. Data from uniformly deflected flaps were compared with data from flaps in the MLC configuration where the outboard segment of three flap segments was deflected downward less than the two inboard segments. The changes in the shear loads in the forward wing spar and at the roots of the stabilators also are presented. The camber control system automatically reconfigures the flaps through varied flight conditions. Configurations having both moderate and full trailing-edge flap deflection were tested. Flight test data were collected at Mach numbers of 0.6, 0.7, 0.8, and 0.9 and dynamic pressures of 300, 450, 600, and 800 lb/sq ft. The Reynolds numbers for these flight conditions ranged from 26 x 10(exp 6) to 54 x 10(exp 6) at the mean aerodynamic chord. Load factor increases of up to 1.0 g achieved with no increase in wing root bending moment with the MLC flap configuration.

  11. World commercial aircraft accidents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kimura, C.Y.

    1993-01-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accidentmore » is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.« less

  12. Fatigue risk management by volunteer fire-fighters: Use of informal strategies to augment formal policy.

    PubMed

    Dawson, Drew; Mayger, Katherine; Thomas, Matthew J W; Thompson, Kirrilly

    2015-11-01

    An increasing number and intensity of catastrophic fire events in Australia has led to increasing demands on a mainly volunteer fire-fighting workforce. Despite the increasing likelihood of fatigue in the emergency services environment, there is not yet a systematic, unified approach to fatigue management in fire agencies across Australia. Accordingly, the aim of this study was to identify informal strategies used in volunteer fire-fighting and examine how these strategies are transmitted across the workforce. Thirty experienced Australian volunteer fire-fighters were interviewed in August 2010. The study identified informal fatigue-management behaviours at the individual, team and brigade level that have evolved in fire-fighting environments and are regularly implemented. However, their purpose was not explicitly recognized as such. This apparent paradox - that fatigue proofing behaviours exist but that they are not openly understood as such - may well resolve a potential conflict between a culture of indefatigability in the emergency services sector and the frequent need to operate safely while fatigued. However, formal controls require fire-fighters and their organisations to acknowledge and accept their vulnerability. This suggests two important areas in which to improve formal fatigue risk management in the emergency services sector: (1) identifying and formalising tacit or informal fatigue coping strategies as legitimate elements of the fatigue risk management system; and (2) developing culturally appropriate techniques for systematically communicating fatigue levels to self and others. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. F-18 HARV yaw rate expansion flight #125 with Inverted Recovery

    NASA Technical Reports Server (NTRS)

    1991-01-01

    NASA's Dryden Flight Research Center, Edwards, CA, used an F-18 Hornet fighter aircraft as its High Angle-of-Attack (Alpha) Research Vehicle (HARV) in a three-phased flight research program lasting from April 1987 until September 1996. The aircraft completed 385 research flights and demonstrated stabilized flight at angles of attack between 65 and 70 degrees using thrust vectoring vanes, a research flight control system, and (eventually) forebody strakes (hinged structures on the forward side of the fuselage to provide control by interacting with vortices, generated at high angles of attack, to create side forces). This combination of technologies provided carefree handling of a fighter aircraft in a part of the flight regime that was otherwise very dangerous. Flight research with the HARV increased our understanding of flight at high angles of attack (angle of the wings with respect to the direction in which the aircraft was heading), enabling designers of U.S. fighter aircraft to design airplanes that will fly safely in portions of the flight envelope that pilots previously had to avoid. Flight 125 with the HARV involved yaw rate expansion up to 50 degrees per second (moving the nose to the left or right at that rate). NASA research pilot Ed Schneider was the pilot, and the purpose of the flight was to look at the spin characteristics of the HARV. The sequence in this particular video clip includes the first and second maneuvers in the flight. On the first maneuver, the pilot attempted to achieve a yaw rate of 40 degrees per second and actually went to 47 degrees. The spin was oscillatory in pitch (up and down) and roll (rotating around the longitudinal axis). Recovery was normal. On the second maneuver of the flight in which Schneider tried to achieve a yaw rate of 40 degrees per second, the aircraft overshot to 54 degrees per second during an oscillatory spin. In the course of the recovery, the aircraft rolled after a large sideslip buildup. Moderate aft stick

  14. Raptors and aircraft

    USGS Publications Warehouse

    Smith, D.G.; Ellis, D.H.; Johnson, T.H.; Glinski, Richard L.; Pendleton, Beth Giron; Moss, Mary Beth; LeFranc, Maurice N.=; Millsap, Brian A.; Hoffman, Stephen W.

    1988-01-01

    Less than 5% of all bird strikes of aircraft are by raptor species, but damage to airframe structure or jet engine dysfunction are likely consequences. Beneficial aircraft-raptor interactions include the use of raptor species to frighten unwanted birds from airport areas and the use of aircraft to census raptor species. Many interactions, however, modify the raptor?s immediate behavior and some may decrease reproduction of sensitive species. Raptors may respond to aircraft stimuli by exhibiting alarm, increased heart rate, flushing or fleeing and occasionally by directly attacking intruding aircraft. To date, most studies reveal that raptor responses to aircraft are brief and do not limit reproduction; however, additional study is needed.

  15. Millimeter-Wave Localizers for Aircraft-to-Aircraft Approach Navigation

    NASA Technical Reports Server (NTRS)

    Tang, Adrian J.

    2013-01-01

    Aerial refueling technology for both manned and unmanned aircraft is critical for operations where extended aircraft flight time is required. Existing refueling assets are typically manned aircraft, which couple to a second aircraft through the use of a refueling boom. Alignment and mating of the two aircraft continues to rely on human control with use of high-resolution cameras. With the recent advances in unmanned aircraft, it would be highly advantageous to remove/reduce human control from the refueling process, simplifying the amount of remote mission management and enabling new operational scenarios. Existing aerial refueling uses a camera, making it non-autonomous and prone to human error. Existing commercial localizer technology has proven robust and reliable, but not suited for aircraft-to-aircraft approaches like in aerial refueling scenarios since the resolution is too coarse (approximately one meter). A localizer approach system for aircraft-to-aircraft docking can be constructed using the same modulation with a millimeterwave carrier to provide high resolution. One technology used to remotely align commercial aircraft on approach to a runway are ILS (instrument landing systems). ILS have been in service within the U.S. for almost 50 years. In a commercial ILS, two partially overlapping beams of UHF (109 to 126 MHz) are broadcast from an antenna array so that their overlapping region defines the centerline of the runway. This is called a localizer system and is responsible for horizontal alignment of the approach. One beam is modulated with a 150-Hz tone, while the other with a 90-Hz tone. Through comparison of the modulation depths of both tones, an autopilot system aligns the approaching aircraft with the runway centerline. A similar system called a glide-slope (GS) exists in the 320-to-330MHz band for vertical alignment of the approach. While this technology has been proven reliable for millions of commercial flights annually, its UHF nature limits

  16. Wind-tunnel studies of the effects of simulated damage on the aerodynamic characteristics of airplanes and missiles

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1979-01-01

    In order to assess the effects on static aerodynamic characteristics of battle damage to an aircraft or missile, wind tunnel studies were performed on models from which all or parts of the wing or horizontal or vertical tail had been removed. The effects of damage on the lift, longitudinal stability, lateral stability and directional stability of a swept-wing fighter are presented, along with the effects of wing removal on the control requirements of a delta-wing fighter. Results indicate that the loss of a major part of the vertical tail will probably result in the loss of the aircraft at any speed, while the loss of major parts of the horizontal tail generally results in catastrophic instability at subsonic speeds but, at low supersonic speeds, may allow the aircraft to return to friendly territory before pilot ejection. Major damage to the wing may be sustained without the loss of aircraft or pilot. The loss of some of the aerodynamic surfaces of cruise or surface-to-air missiles may result in catastrophic instability or may permit a ballistic trajectory to be maintained, depending upon the location of the lost surface with respect to the center of gravity of the missile.

  17. X-29A flight control system performance during flight test

    NASA Technical Reports Server (NTRS)

    Chin, J.; Chacon, V.; Gera, J.

    1987-01-01

    An account is given of flight control system performance results for the X-29A forward-swept wing 'Advanced Technology Demonstrator' fighter aircraft, with attention to its software and hardware components' achievement of the requisite levels of system stability and desirable aircraft handling qualities. The Automatic Camber Control Logic is found to be well integrated with the stability loop of the aircraft. A number of flight test support software programs developed by NASA facilitated monitoring of the X-29A's stability in real time, and allowed the test team to clear the envelope with confidence.

  18. Investigation of a supersonic cruise fighter model flow field

    NASA Technical Reports Server (NTRS)

    Reubush, D. E.; Bare, E. A.

    1985-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to survey the flow field around a model of a supersonic cruise fighter configuration. Local values of angle of attack, side flow, Mach number, and total pressure ratio were measured with a single multi-holed probe in three survey areas on a model previously used for nacelle/nozzle integration investigations. The investigation was conducted at Mach numbers of 0.6, 0.9, and 1.2, and at angles of attack from 0 deg to 10 deg. The purpose of the investigation was to provide a base of experimental data with which theoretically determined data can be compared. To that end the data are presented in tables as well as graphically, and a complete description of the model geometry is included as fuselage cross sections and wing span stations. Measured local angles of attack were generally greater than free stream angle of attack above the wing and generally smaller below. There were large spanwise local angle-of-attack and side flow gradients above the wing at the higher free stream angles of attack.

  19. Oxygen mask related nasal integument and osteocartilagenous disorders in F-16 fighter pilots.

    PubMed

    Schreinemakers, J Rieneke C; Westers, Paul; van Amerongen, Pieter; Kon, Moshe

    2013-01-01

    A preliminary survey showed half of the participating Royal Netherlands Air Force (RNLAF) F-16 fighter pilots to have nasal integument and osteocartilagenous disorders related to wearing in-flight oxygen masks. To make an inventory of these disorders and possible associated factors. All RNLAF F-16 pilots were requested to fill out a semi-structured questionnaire for a cross-sectional survey. Additionally, one squadron in The Netherlands and pilots in operational theater were asked to participate in a prospective study that required filling out a pain score after each flight. Pilot- and flight-related variables on all participants were collected from the RNLAF database. A linear mixed model was built to identify associated factors with the post-flight pain score. The response rate to the survey was 83%. Ninety of the 108 participants (88%, 6 missing) reported tenderness, irritation, pain, erythema, skin lesions, callous skin, or swelling of nasal bridge integument or architecture. Seventy-two participants (71%, 6 missing) reported their symptoms to be troublesome after a mean of 6±3 out of 10 flights (0;10, 54 missing). Sixty-six pilots participated in scoring post-flight pain. Pain scores were significantly higher if a participant had ≥3 nasal disorders, after longer than average flights, after flying abroad, and after flying with night vision goggles (respectively +2.7 points, p = 0.003; +0.2 points, p = 0.027; +1.8 points, p = 0.001; +1.2 points p = 0.005). Longer than average NVG flights and more than average NVG hours per annum decreased painscores (respectively -0.8 points, p = 0.017; -0.04 points, p = 0.005). The majority of the RNLAF F-16 fighter pilot community has nasal disorders in the contact area of the oxygen mask, including pain. Six pilot- or flight-related characteristics influence the experienced level of pain.

  20. Experiments in Aircraft Roll-Yaw Control using Forebody Tangential Blowing

    NASA Technical Reports Server (NTRS)

    Pedreiro, Nelson

    1997-01-01

    Advantages of flight at high angles of attack include increased maneuverability and lift capabilities. These are beneficial not only for fighter aircraft, but also for future supersonic and hypersonic transport aircraft during take-off and landing. At high angles of attack the aerodynamics of the vehicle are dominated by separation, vortex shedding and possibly vortex breakdown. These phenomena severely compromise the effectiveness of conventional control surfaces. As a result, controlled flight at high angles of attack is not feasible for current aircraft configurations. Alternate means to augment the control of the vehicle at these flight regimes are therefore necessary. The present work investigates the augmentation of an aircraft flight control system by the injection of a thin sheet of air tangentially to the forebody of the vehicle. This method, known as Forebody Tangential Blowing (FTB), has been proposed as an effective means of increasing the controllability of aircraft at high angles of attack. The idea is based on the fact that a small amount of air is sufficient to change the separation lines on the forebody. As a consequence, the strength and position of the vortices are altered causing a change on the aerodynamic loads. Although a very effective actuator, forebody tangential blowing is also highly non-linear which makes its use for aircraft control very difficult. In this work, the feasibility of using FTB to control the roll-yaw motion of a wind tunnel model was demonstrated both through simulations and experimentally. The wind tunnel model used in the experiments consists of a wing-body configuration incorporating a delta wing with 70-degree sweep angle and a cone-cylinder fuselage. The model is equipped with forebody slots through which blowing is applied. There are no movable control surfaces, therefore blowing is the only form of actuation. Experiments were conducted at a nominal angle of attack of 45 degrees. A unique apparatus that constrains

  1. Research and technology, 1983

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Highlights of major accomplishments and applications made during the past year illustrate the broad range of research and technology activities at the Langley Research Center. Advances are reported in the following areas: systems engineering and operation; aeronautics; electronics; space applications; aircraft and spacecraft structures; composite structures; laminar flow control; subsonic transport aircraft; and supersonic fighter concepts. Technology utilization efforts described cover a hyperthermia monitor, a lightweight composite wheelchair; and a vehicle ride quality meter.

  2. Maintenance Metrics for Jovial (J73) Software

    DTIC Science & Technology

    1988-12-01

    pacing technology in advanced fighters, just as it has in most other weapon systems and information systems" ( Canan , 1986:49). Another reason for...the magnitude of the software inside an aircraft may represent only a fraction of that aircraft’s total software requirement." ( Canan , 1986:49) One more...art than a science" marks program development as a largely labor-intensive, human endeavor ( Canan , 1986:50). Individual effort and creativity therefore

  3. ANALYSIS OF THE PATTERN AND MECHANISM OF ELBOW INJURIES RELATED TO ARMBAR-TYPE ARMLOCKS IN JIU-JITSU FIGHTERS.

    PubMed

    Almeida, Thiago Bernardo Carvalho DE; Dobashi, Eiffel Tsuyoshi; Nishimi, Alexandre Yukio; Almeida, Eduardo Bernardo DE; Pascarelli, Luciano; Rodrigues, Luciano Miller Reis

    2017-01-01

    The objective of this study was to analyze elbow injuries and their probable mechanism in Jiu-Jitsu fighters resulting from the armbar-type armlock. We evaluated 5 high-performance Jiu-Jitsu fighters from the Gracie Elite gym who were injured during a tournament. All were healthy males with a mean age of 28.8 years. The right arm was involved in three patients (60%). The athletes were followed for approximately 4.6 months, and pain was present in all cases. Clinical examination of the elbow was performed immediately after the injury and when magnetic resonance imaging (MRI) was performed. The radiography showed no changes. Clinical examination detected specific tender points on the medial and anterior topography of the elbows, but no ligamentous instability of the elbow was seen during dynamic testing. The main MRI findings were injury to the common flexor tendon and the ulnar collateral ligament, bone contusion of the distal humerus and olecranon, and joint effusion. The main pattern of injury indicated by the MRI in the athletes was injury to the medial elbow complex. The primary mechanism that determined the injury was most likely elbow hyperextension applied with the forearm in neutral position of forearm. Level of Evidence IV, Case Series.

  4. ANALYSIS OF THE PATTERN AND MECHANISM OF ELBOW INJURIES RELATED TO ARMBAR-TYPE ARMLOCKS IN JIU-JITSU FIGHTERS

    PubMed Central

    ALMEIDA, THIAGO BERNARDO CARVALHO DE; DOBASHI, EIFFEL TSUYOSHI; NISHIMI, ALEXANDRE YUKIO; ALMEIDA, EDUARDO BERNARDO DE; PASCARELLI, LUCIANO; RODRIGUES, LUCIANO MILLER REIS

    2017-01-01

    ABSTRACT Objective: The objective of this study was to analyze elbow injuries and their probable mechanism in Jiu-Jitsu fighters resulting from the armbar-type armlock. Methods: We evaluated 5 high-performance Jiu-Jitsu fighters from the Gracie Elite gym who were injured during a tournament. All were healthy males with a mean age of 28.8 years. The right arm was involved in three patients (60%). The athletes were followed for approximately 4.6 months, and pain was present in all cases. Clinical examination of the elbow was performed immediately after the injury and when magnetic resonance imaging (MRI) was performed. The radiography showed no changes. Clinical examination detected specific tender points on the medial and anterior topography of the elbows, but no ligamentous instability of the elbow was seen during dynamic testing. Results: The main MRI findings were injury to the common flexor tendon and the ulnar collateral ligament, bone contusion of the distal humerus and olecranon, and joint effusion. Conclusion: The main pattern of injury indicated by the MRI in the athletes was injury to the medial elbow complex. The primary mechanism that determined the injury was most likely elbow hyperextension applied with the forearm in neutral position of forearm. Level of Evidence IV, Case Series. PMID:29081707

  5. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  6. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  7. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  8. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... engines, and propellers. 21.6 Section 21.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  9. Sonic boom startle effects : report of a field study.

    DOT National Transportation Integrated Search

    1973-07-01

    The study reports the results of a sonic boom field study conducted in Sweden during October 1972. Ten female subjects were tested indoors on each of six days. Two age groups were studied: 20-35 and 50-65 years. Fighter aircraft flying at various hei...

  10. Shock capturing finite difference algorithms for supersonic flow past fighter and missile type configurations

    NASA Technical Reports Server (NTRS)

    Osher, S.

    1984-01-01

    The construction of a reliable, shock capturing finite difference method to solve the Euler equations for inviscid, supersonic flow past fighter and missile type configurations is highly desirable. The numerical method must have a firm theoretical foundation and must be robust and efficient. It should be able to treat subsonic pockets in a predominantly supersonic flow. The method must also be easily applicable to the complex topologies of the aerodynamic configuration under consideration. The ongoing approach to this task is described and for steady supersonic flows is presented. This scheme is the basic numerical method. Results of work obtained during previous years are presented.

  11. Hypersonic aircraft design

    NASA Technical Reports Server (NTRS)

    Alkamhawi, Hani; Greiner, Tom; Fuerst, Gerry; Luich, Shawn; Stonebraker, Bob; Wray, Todd

    1990-01-01

    A hypersonic aircraft is designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and it was decided that the aircraft would use one full scale turbofan-ramjet. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic region. After considering aerodynamics, aircraft design, stability and control, cooling systems, mission profile, and landing systems, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets are also taken into consideration in the final design. A hypersonic aircraft was designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and a full scale turbofan-ramjet was chosen. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic reqion. After the aerodynamics, aircraft design, stability and control, cooling systems, mission profile, landing systems, and their physical interactions were considered, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets were also considered in the designing process.

  12. Experience with high performance V/STOL fighter projects at MBB

    NASA Technical Reports Server (NTRS)

    Aulehla, F.; Kissel, G. K.

    1981-01-01

    Flight control systems and aerodynamic aspects of experimental V/STOL aircraft are discussed. The VJ 101 C featured tilting engines for increased thrust, reheat for takeoff, simple translation, triangular decentralization of the engines for thrust modulation, and moderate ground effects. Two experimental aircraft were built, with and without reheat, capable of Mach 2 and Mach 1.04, respectively. The mechanical flight control system and tests are outlined, both for hover rig and flight configurations. Ground suction, acoustic and thermal loading, sodium silicate coatings to avoid ground corrosion, and recirculation are considered. Results of the follow-on project to the VJ 101 C, the AVS, which was developed by NASA, are reviewed, and it is noted that trends toward thrust-to-weight ratios exceeding one, in concert with low wing loading, favor the development of V/STOL aircraft.

  13. Special Course on Fundamentals of Fighter Aircraft Design

    DTIC Science & Technology

    1987-10-01

    mounted centrally on a cylindrical fuselage of circular cross-section. Here the fuselage interference is shown by a calculation with an exact...M. and Schiff, L.B., "Aerodynamic Mathematical Modeling - Basic Concepts", AGARD-LS-114, 1981, Lecture 1. 30. Malcolm, G.N., "Rotary and Magnus ...thin cylindrical Intake 1.5.3. Real Intake equivalence 1.5.4. Lip thickness and auxiliary intake design 1.6. AIR INTAKE RADAR CROSS SECTION (R.C.S

  14. Propulsion controlled aircraft computer

    NASA Technical Reports Server (NTRS)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  15. Unmanned aircraft systems

    USDA-ARS?s Scientific Manuscript database

    Unmanned platforms have become increasingly more common in recent years for acquiring remotely sensed data. These aircraft are referred to as Unmanned Airborne Vehicles (UAV), Remotely Piloted Aircraft (RPA), Remotely Piloted Vehicles (RPV), or Unmanned Aircraft Systems (UAS), the official term used...

  16. Transition from lab to flight demo for model-based FLIR ATR and SAR-FLIR fusion

    NASA Astrophysics Data System (ADS)

    Childs, Martin B.; Carlson, Karen M.; Pujara, Neeraj

    2000-08-01

    Model-based automatic target recognition (ATR) using forward- looking infrared (FLIR) imagery, and using FLIR imagery combined with cues from a synthetic aperture radar (SAR) system, has been successfully demonstrated in the laboratory. For the laboratory demonstration, FLIR images, platform location, sensor data, and SAR cues were read in from files stored on computer disk. This ATR system, however, was intended to ultimately be flown in a fighter aircraft. We discuss the transition from laboratory demonstration to flight demonstration for this system. The obvious changes required were in the interfaces: the flight system must get live FLIR imagery from a sensor; it must get platform location, sensor data, and controls from the avionics computer in the aircraft via 1553 bus; and it must get SAR cues from the on-board SAR system, also via 1553 bus. Other changes included the transition to rugged hardware that would withstand the fighter aircraft environment, and the need for the system to be compact and self-contained. Unexpected as well as expected challenges were encountered. We discuss some of these challenges, how they were met, and the performance of the flight-demonstration system.

  17. A five states survivability model for missions with ground-to-air threats

    NASA Astrophysics Data System (ADS)

    Erlandsson, Tina; Niklasson, Lars

    2013-05-01

    Fighter pilots are exposed to the risk of getting hit by enemy fire when flying missions with ground-to-air threats. A tactical support system including a survivability model could aid the pilot to assess and handle this risk. The survivability model presented here is a Markov model with five states; Undetected, Detected, Tracked, Engaged and Hit. The output from the model is the probabilities that the aircraft is in these states during the mission. The enemy's threat systems are represented with sensor and weapon areas and the transitions between the states depend on whether or not the aircraft is within any of these areas. Contrary to previous work, the model can capture the behaviors that the enemy's sensor systems communicate and that the risk of getting hit depends on the enemy's knowledge regarding the aircraft's kinematics. The paper includes a discussion regarding the interpretation of the states and the factors that influence the transitions between the states. Further developments are also identified for using the model to aid fighter pilots and operators of unmanned aerial vehicles with planning and evaluating missions as well as analyzing the situation during flight.

  18. Fun!

    ERIC Educational Resources Information Center

    Horne, Thomas

    1988-01-01

    Describes four IBM compatible flight simulator software packages: (1) "Falcon," air to air combat in an F-16 fighter; (2) "Chuck Yeager's Advanced Flight Trainer," test flight 14 different aircraft; (3) "Jet," air to air combat; and (4) "Flight Simulator," a realistic PC flight simulator program. (MVL)

  19. Schweinfurt Raids and the Pause in Daylight Strategic Bombing

    DTIC Science & Technology

    2008-06-13

    fundamentally flawed doctrine based upon faulty assumptions and the end result was the heavy loss of aircrew and aircraft. The Schweinfurt missions...maneuverable German fighters due to the Lightning’s turbochargers performing badly at higher altitudes in the high humidity and colder temperatures. The P-38

  20. Building Afghanistan’s Security Forces in Wartime: The Soviet Experience

    DTIC Science & Technology

    2011-01-01

    weaponry (aircraft, rockets , and thou- sands of Shmel flamethrowers), and funds to pay fighters.16 The Soviets 13 Liakhovskii, 2009. 14 Timofeev...effort to build an effective state in Afghanistan was a failure, prospects for success in developing the security forces of that state were, in retro

  1. Egypt’s Air War in Yemen

    DTIC Science & Technology

    2010-03-01

    transports. 15 They also had Yak -11 piston-engine fighters, which were often used for reconnaissance, and Mi-4 transport helicopters in theater...happened with 20 Yak aircraft received from Czechoslovakia. Most remained on the airfields to rust, with some never leaving their crates. In the late

  2. Combustion toxicology of epoxy/carbon fiber composites

    NASA Technical Reports Server (NTRS)

    Cagliostro, D. E.

    1981-01-01

    A combustion toxicology test was developed to screen materials for aerospace applications. The system is called the radiant panel test facility. A description of the facility and some preliminary results from tests on a Navy 3501-6AS composite, a typical composite for fighter aircraft, are presented.

  3. NASA aerodynamics program

    NASA Technical Reports Server (NTRS)

    Holmes, Bruce J.; Schairer, Edward; Hicks, Gary; Wander, Stephen; Blankson, Isiaiah; Rose, Raymond; Olson, Lawrence; Unger, George

    1990-01-01

    Presented here is a comprehensive review of the following aerodynamics elements: computational methods and applications, computational fluid dynamics (CFD) validation, transition and turbulence physics, numerical aerodynamic simulation, drag reduction, test techniques and instrumentation, configuration aerodynamics, aeroacoustics, aerothermodynamics, hypersonics, subsonic transport/commuter aviation, fighter/attack aircraft and rotorcraft.

  4. Live fire testing requirements - Assessing the impact

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    O'Bryon, J.F.

    1992-08-01

    Full-up live-fire testing (LFT) of aircraft configured for combat is evaluated in terms of the practical implications of the technique. LFT legislation requires the testing of tactical fighters, helicopters, and other aircraft when they are loaded with the flammables and explosives associated with combat. LFT permits the study of damage mechanisms and battle-damage repair techniques during the design phase, and probability-of-kill estimates and novel systems designs can be developed based on LFT data.

  5. Acceleration Tolerance After Ingestion of a Commercial Energy Drink

    DTIC Science & Technology

    2010-12-01

    with all of the ’energy’ingredients re- moved (i.e., no high - fructose corn syrup , B-vitamins, ginseng, guarana, L-carnitine, or taurine). In this paper...lerance durat ion. Keywords: caffeine, C tolerance, centrifuge. A DVANCED FIGHTER aircraft are capable of oper- -f1.ating in high -G environments and are...during a high -G aircraft ma- neuver to prevent G-induced loss of consciousness (GLOC). The inability to maintain and repeatedly per- form an AGSM can

  6. ECN-14283

    NASA Image and Video Library

    1980-12-30

    The Highly Maneuverable Aircraft Technology (HiMAT) research vehicle is shown here mated to a wing pylon on NASA’s B-52 mothership aircraft. The HiMAT was a technology demonstrator to test structures and configurations for advanced fighter concepts. Over the course of more than 40 years, the B-52 proved a valuable workhorse for NASA’s Dryden Flight Research Center (under various names), launching a wide variety of vehicles and conducting numerous other research flights.

  7. F-22 cockpit avionics: a systems integration success story

    NASA Astrophysics Data System (ADS)

    Greeley, Kevin W.; Schwartz, Richard J.

    2000-08-01

    The F-22 'Raptor' is being developed and manufactured as multi-role fighter aircraft for the 'air dominance' mission. The F-22 team is led by Lockheed Martin, with Boeing and Pratt & Whitney as partners. The F-22 weapons system combines supersonic cruise, maneuverability, stealth, and an extensive suite of tightly integrated sensors to achieve a high level of lethality and invulnerability against current and projected threat systems such as fighter aircraft and surface to air missiles. Despite high automation of the complex systems installed in the F-22, the pilot is heavily tasked for air battle management. Response timelines are compressed due to supersonic cruise velocities. These factors challenge the Pilot Vehicle Interface (PVI) design. This paper discusses the team's response to these challenges, describing the physical cockpit layout, its controls and displays, and the hardware architecture, software tools, and development process used to mature the F-22 'Raptor' weapons system, including a review of Human Factors design considerations for F-22 displays.

  8. Small transport aircraft technology

    NASA Technical Reports Server (NTRS)

    Williams, L. J.

    1983-01-01

    Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.

  9. Airborne Subscale Transport Aircraft Research Testbed: Aircraft Model Development

    NASA Technical Reports Server (NTRS)

    Jordan, Thomas L.; Langford, William M.; Hill, Jeffrey S.

    2005-01-01

    The Airborne Subscale Transport Aircraft Research (AirSTAR) testbed being developed at NASA Langley Research Center is an experimental flight test capability for research experiments pertaining to dynamics modeling and control beyond the normal flight envelope. An integral part of that testbed is a 5.5% dynamically scaled, generic transport aircraft. This remotely piloted vehicle (RPV) is powered by twin turbine engines and includes a collection of sensors, actuators, navigation, and telemetry systems. The downlink for the plane includes over 70 data channels, plus video, at rates up to 250 Hz. Uplink commands for aircraft control include over 30 data channels. The dynamic scaling requirement, which includes dimensional, weight, inertial, actuator, and data rate scaling, presents distinctive challenges in both the mechanical and electrical design of the aircraft. Discussion of these requirements and their implications on the development of the aircraft along with risk mitigation strategies and training exercises are included here. Also described are the first training (non-research) flights of the airframe. Additional papers address the development of a mobile operations station and an emulation and integration laboratory.

  10. MicroRNA-378 regulates neural stem cell proliferation and differentiation in vitro by modulating Tailless expression

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huang, Yanxia; Department of Rehabilitation, Xi'an Children's Hospital, Xi'an 710003; Liu, Xiaoguai

    Previous studies have suggested that microRNAs (miRNAs) play an important role in regulating neural stem cell (NSC) proliferation and differentiation. However, the precise role of miRNAs in NSC remains largely unexplored. In this study, we showed that miR-378 can target Tailless (TLX), a critical regulator of NSC, to regulate NSC proliferation and differentiation. By bioinformatic algorithms, miR-378 was found to have a predicted target site in the 3′-untranslated region of TLX, which was verified by a dual-luciferase reporter assay. The expression of miR-378 was increased during NSC differentiation and inversely correlated with TLX expression. qPCR and Western blot analysis alsomore » showed that miR-378 negatively regulated TLX mRNA and protein expression in neural stem cells (NSCs). Intriguingly, overexpression of miR-378 increased NSC differentiation and reduced NSC proliferation, whereas suppression of miR-378 led to decreased NSC differentiation and increased NSC proliferation. Moreover, the downstream targets of TLX, including p21, PTEN and Wnt/β-catenin were also found to be regulated by miR-378. Additionally, overexpression of TLX rescued the NSC proliferation deficiency induced by miR-378 overexpression and abolished miR-378-promoted NSC differentiation. Taken together, our data suggest that miR-378 is a novel miRNA that regulates NSC proliferation and differentiation via targeting TLX. Therefore, manipulating miR-378 in NSCs could be a novel strategy to develop novel interventions for the treatment of relevant neurological disorders. - Highlights: • miR-378 targeted and regulated TLX. • miR-378 was increased during NSC differentiation. • miR-378 regulated NSC proliferation and differentiation. • miR-378 regulated NSC self-renew through TLX.« less

  11. Why aircraft disinsection?

    PubMed

    Gratz, N G; Steffen, R; Cocksedge, W

    2000-01-01

    A serious problem is posed by the inadvertent transport of live mosquitoes aboard aircraft arriving from tropical countries where vector-borne diseases are endemic. Surveys at international airports have found many instances of live insects, particularly mosquitoes, aboard aircraft arriving from countries where malaria and arboviruses are endemic. In some instances mosquito species have been established in countries in which they have not previously been reported. A serious consequence of the transport of infected mosquitoes aboard aircraft has been the numerous cases of "airport malaria" reported from Europe, North America and elsewhere. There is an important on-going need for the disinsection of aircraft coming from airports in tropical disease endemic areas into nonendemic areas. The methods and materials available for use in aircraft disinsection and the WHO recommendations for their use are described.

  12. Technical and Tactical Aspects that Differentiate Winning and Losing Performances in Elite Male Karate Fighters.

    PubMed

    Vidranski, Tihomir; Sertić, Hrvoje; Jukić, Josefina

    2015-07-01

    The purpose of this research was to identify the fighters' technical and tactical activity indicators in order to determine indicator significance regarding situational efficiency and designation between winning and losing performances in a karate match. We scientifically observed a sample of 274 male contesters of 137 karate matches during the 2008 World Karate Championship in Tokyo. Each individual competitor was observed in maximum of three matches. The matches were recorded using a DVD camera in order to collect data for further analysis, and the sample was further described using 48 technical and tactical indicators of situational efficiency and match outcome variables. The obtained results indicate that a karate match is composed of 91% of non-scoring techniques and 9% of scoring techniques in the total technique frequency. On this basis a significant difference in the situational efficiency between the match winners and the losing contesters has been discovered. Those two groups of fighters exhibit a statistically significant difference (p<0.05) in 11 out of 21 observed variables of situational efficiency in the table of derived situational indicators. A prevalence of non-scoring techniques suggests that energy demand and technical and tactical requirements of a karate match are in the largest extent defined by non-scoring techniques. Therefore, it would be a grave mistake to disregard non-scoring karate techniques in any future situational efficiency studies. It has been discovered that the winners differ from the defeated contesters by a higher level of situational efficiency in their executed techniques, which incorporate versatility, biomechanical and structural complexity, topological diversity and a specific tactical concept of technique use in the attack phase.

  13. Aircraft Survivability: UAVs and Manned Aircraft - Increasing Effectiveness and Survivability, Fall 2002

    DTIC Science & Technology

    2002-01-01

    techniques that interface with the composite structure to attach opaque armor(s) to compos- ite aircraft structure. Over a period of four years...2002 2. REPORT TYPE 3. DATES COVERED 00-00-2002 to 00-00-2002 4. TITLE AND SUBTITLE Aircraft Survivability: UAVs and Manned Aircraft ...survivability concepts to UAV program offices and airframe manufacturers. 11 Aircraft Fire Protection Techniques—Application to UAVs by Ms. Ginger Bennett

  14. Aircraft disinsection.

    PubMed

    Rayman, Russell B

    2006-07-01

    Aircraft disinsection has been an international practice since the 1920s, the purpose of which is to protect public health, the environment, agriculture, and livestock by the eradication of disease vectors. Although most nations of the world have discontinued this practice, about 20 continue with this requirement. Aircraft disinsection is sanctioned by international law with the World Health Organization (WHO) publishing general procedural guidelines in the International Health Regulations (IHR). There are currently four acceptable procedures: blocks away, top of descent, on arrival, and residual. A 2% pyrethrum solution, a naturally occurring substance found in the chrysanthemum flower, or several synthetic pyrethroids, are the recommended agents because they are extremely effective insecticides which pose minimal health risks. Although the use of insecticides for aircraft disinsection is controversial, national policies compelling this requirement must be respected. This paper will explore the background of aircraft disinsection, the procedures, the types of agents, and the toxicity. If aircraft disinsection is regulatory policy, it should be done in accordance with WHO procedures. Residual application is probably the most efficacious method. The use of air curtains or plastic strips should be explored as an alternative to the use of chemicals.

  15. Proposed Relocation of the 37th Tactical Fighter Wing and Other Tactical Force Structure Actions. Draft Environmental Impact Statement

    DTIC Science & Technology

    1991-02-05

    finance , insurance and real estate FL flight level ft feet FWS U.S. Fish and Wildlife Service FWW Fighter Weapon Wing FY fiscal year GAF German Air Force...three locations are related to socioeconomics. Potential effects of the realignment on employment, income, public finance , housing, and local economic...Manufacturing 89 107 1 Transportation, communications, and utilities 135 202 2 * Wholesale and retail tradeb 514 594 5 3 Finance , insurance, and real estate 216

  16. Aerospace Knowledge Magazine (Selected Articles),

    DTIC Science & Technology

    1986-01-15

    country employed Soviet fighters. It was reported in foreign journals that there was no Doppler navigation system on these aircraft. Furthermore, a Sirena 2...radar warning and homing system with poorer performance was used instead of the Sirena 3 which provides 3600 coverage. The iden- tification friend or

  17. ECN-14284

    NASA Image and Video Library

    1980-12-30

    A close-up view of the Highly Maneuverable Aircraft Technology (HiMAT) research vehicle attached to a wing pylon on NASA’s B-52 mothership during a 1980 test flight. The HiMAT used sharply swept-back wings and a canard configuration to test possible technology for advanced fighters.

  18. Hexavalent Chromium and Isocyanate Exposures during Military Aircraft Painting under Crossflow Ventilation

    PubMed Central

    Bennett, James S.; Marlow, David A.; Nourian, Fariba; Breay, James; Hammond, Duane

    2016-01-01

    Exposure control systems performance was investigated in an aircraft painting hangar. The ability of the ventilation system and respiratory protection program to limit worker exposures was examined through air sampling during painting of F/A-18C/D strike fighter aircraft, in four field surveys. Air velocities were measured across the supply filter, exhaust filter, and hangar midplane under crossflow ventilation. Air sampling conducted during painting process phases (wipe-down, primer spraying, and topcoat spraying) encompassed volatile organic compounds, total particulate matter, Cr[VI], metals, nitroethane, and hexamethylene diisocyanate, for two worker groups: sprayers and sprayer helpers (“hosemen”). One of six methyl ethyl ketone and two of six methyl isobutyl ketone samples exceeded the short term exposure limits of 300 and 75 ppm, with means 57 ppm and 63 ppm, respectively. All 12 Cr[VI] 8-hr time-weighted averages exceeded the recommended exposure limit of 1 µg/m3, 11 out of 12 exceeded the permissible exposure limit of 5 µg/m3, and 7 out of 12 exceeded the threshold limit value of 10 µg/m3, with means 38 µg/m3 for sprayers and 8.3 µg/m3 for hosemen. Hexamethylene diisocyanate means were 5.95 µg/m3 for sprayers and 0.645 µg/m3 for hosemen. Total reactive isocyanate group—the total of monomer and oligomer as NCO group mass—showed six of 15 personal samples exceeded the United Kingdom Health and Safety Executive workplace exposure limit of 20 µg/m3, with means 50.9 µg/m3 for sprayers and 7.29 µg/m3 for hosemen. Several exposure limits were exceeded, reinforcing continued use of personal protective equipment. The supply rate, 94.4 m3/s (200,000 cfm), produced a velocity of 8.58 m/s (157 fpm) at the supply filter, while the exhaust rate, 68.7 m3/s (146,000 cfm), drew 1.34 m/s (264 fpm) at the exhaust filter. Midway between supply and exhaust locations, the velocity was 0.528 m/s (104 fpm). Supply rate exceeding exhaust rate created re

  19. Rating aircraft on energy

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.

    1974-01-01

    Questions concerning the energy efficiency of aircraft compared to ground transport are considered, taking into account as energy intensity the energy consumed per passenger statute mile. It is found that today's transport aircraft have an energy intensity potential comparable to that of ground modes. Possibilities for improving the energy density are also much better in the case of aircraft than in the case of ground transportation. Approaches for potential reductions in aircraft energy consumption are examined, giving attention to steps for increasing the efficiency of present aircraft and to reductions in energy intensity obtainable by the introduction of new aircraft utilizing an advanced technology. The use of supercritical aerodynamics is discussed along with the employment of composite structures, advances in propulsion systems, and the introduction of very large aircraft. Other improvements in fuel economy can be obtained by a reduction of skin-friction drag and a use of hydrogen fuel.

  20. Aircraft Inspection for the General Aviation Aircraft Owner.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    Presented is useful information for owners, pilots, student mechanics, and others with aviation interests. Part I of this booklet outlines aircraft inspection requirements, owner responsibilities, inspection time intervals, and sources of basic information. Part II is concerned with the general techniques used to inspect an aircraft. (Author/JN)

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