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1

Modal control of an oblique wing aircraft  

NASA Technical Reports Server (NTRS)

A linear modal control algorithm is applied to the NASA Oblique Wing Research Aircraft (OWRA). The control law is evaluated using a detailed nonlinear flight simulation. It is shown that the modal control law attenuates the coupling and nonlinear aerodynamics of the oblique wing and remains stable during control saturation caused by large command inputs or large external disturbances. The technique controls each natural mode independently allowing single-input/single-output techniques to be applied to multiple-input/multiple-output systems.

Phillips, James D.

1989-01-01

2

Application of modern control design methodology to oblique wing research aircraft  

NASA Technical Reports Server (NTRS)

A Linear Quadratic Regulator synthesis technique was used to design an explicit model following control system for the Oblique Wing Research Aircraft (OWRA). The forward path model (Maneuver Command Generator) was designed to incorporate the desired flying qualities and response decoupling. The LQR synthesis was based on the use of generalized controls, and it was structured to provide a proportional/integral error regulator with feedforward compensation. An unexpected consequence of this design approach was the ability to decouple the control synthesis into separate longitudinal and lateral directional designs. Longitudinal and lateral directional control laws were generated for each of the nine design flight conditions, and gain scheduling requirements were addressed. A fully coupled 6 degree of freedom open loop model of the OWRA along with the longitudinal and lateral directional control laws was used to assess the closed loop performance of the design. Evaluations were performed for each of the nine design flight conditions.

Vincent, James H.

1991-01-01

3

AD-1 oblique wing aircraft program  

NASA Technical Reports Server (NTRS)

The oblique wing concept for super- and subsonic transport was assessed by analysis and wind tunnel radio control model and remotely piloted vehicle testing. A one-sixth scale wind tunnel model and a low speed manned oblique wing research airplane (AD-1) were developed. Model wind tunnel test data on dynamic structural response characteristics were used in a simulator to develop the control system. The airplane is of simple design with fiber glass skin, weight of approximately 2100 lbs and speeds of up to 175 knots at altitudes up to 15,000 ft. Flight testing will investigate handling and flying qualities, oblique wing flight control characteristics, aeroelastic wing design and will compare actual with predicted aerodynamic characteristics. Nineteen flights were made at 12,000 to 13,000 feet with speeds of 100-160 knots. Flutter clearance as a function of wing sweep angle is now under investigation.

Andrews, W. H.; Sim, A. G.; Monaghan, R. C.; Felt, L. R.; Mcmurty, T. C.; Smith, R. C.

1980-01-01

4

Aeroelastic control of oblique-wing aircraft  

NASA Technical Reports Server (NTRS)

The U.S. Navy and NASA are currently involved in the design and development of an unsymmetric-skew-wing aircraft capable of 65 deg wing sweep and flight at Mach 1.6. A generic skew-wing aircraft model was developed for 45 deg wing skew at a flight condition of Mach 0.70 and 3048 m altitude. At this flight condition the aircraft has a wing flutter mode. An active implementable control law was developed using the linear quadratic Gaussian design technique. A method of modal residualization was used to reduce the order of the controller used for flutter suppression.

Burken, J. J.; Alag, G. S.; Gilyard, G. B.

1986-01-01

5

Integrated aerodynamic and control system design of oblique wing aircraft. Ph.D. Thesis  

NASA Technical Reports Server (NTRS)

An efficient high speed aircraft design must achieve a high lift to drag ratio at transonic and supersonic speeds. In 1952 Dr. R. T. Jones proved that for any flight Mach number minimum drag at a fixed lift is achieved by an elliptic wing planform with an appropriate oblique sweep angle. Since then, wind tunnel tests and numerical flow models have confirmed that the compressibility drag of oblique wing aircraft is lower than similar symmetrical sweep designs. At oblique sweep angles above thirty degrees the highly asymmetric planform gives rise to aerodynamic and inertia couplings which affect stability and degrade the aircraft's handling qualities. In the case of the NASA-Rockwell Oblique Wing Research Aircraft, attempts to improve the handling qualities by implementing a stability augmentation system have produced unsatisfactory results because of an inherent lack of controllability in the proposed design. The present work focuses on improving the handling qualities of oblique wing aircraft by including aerodynamic configuration parameters as variables in the control system synthesis to provide additional degrees of freedom with which to further decouple the aircraft's response. Handling qualities are measured using a quadratic cost function identical to that considered in optimal control problems, but the controller architecture is not restricted to full state feedback. An optimization procedure is used to simultaneously solve for the aircraft configuration and control gains which maximize a handling qualities measure, while meeting imposed constraints on trim. In some designs wing flexibility is also modeled and reduced order controllers are implemented. Oblique wing aircraft synthesized by this integrated design method show significant improvement in handling qualities when compared to the originally proposed closed loop aircraft. The integrated design synthesis method is then extended to show how handling qualities may be traded for other types of mission performance (drag, weight, etc.). Examples are presented which show how performance can be maximized while maintaining a desired level of handling quality.

Morris, Stephen James

1990-01-01

6

An Investigation of Supersonic Aeroelastic Characteristics of Oblique Winged Aircraft.  

National Technical Information Service (NTIS)

Two formulations of the oblique wing flutter problem are presented: one formulation allows wing bending deformations and the rigid body roll degree of freedom while the second formulation includes bending-torsional deformation and roll degrees of freedom....

T. A. Weisshaar

1975-01-01

7

Output model-following control synthesis for an oblique-wing aircraft  

NASA Technical Reports Server (NTRS)

Recent interest in oblique-wing aircraft has focused on the potential aerodynamic performance advantage of a variable-skew oblique wing over a conventional or symmetric sweep wing. Unfortunately, the resulting asymmetric configuration has significant aerodynamic and inertial cross-coupling between the aircraft longitudinal and lateral-directional axes. Presented here is a decoupling control law synthesis technique that integrates stability augmentation, decoupling, and the direct incorporation of desired handling qualities into an output feedback controller. The proposed design technique uses linear quadratic regulator concepts in the framework of explicit model following. The output feedback strategy used is a suboptimal projection from the state space to the output space. Dynamics are then introduced into the controller to improve steady-state performance and increase system robustness. Closed-loop performance is shown by application of the control laws to the linearized equations of motion and nonlinear simulation of an oblique-wing aircraft.

Pahle, Joseph W.

1990-01-01

8

The Leading Edge 250: Oblique wing aircraft configuration project, volume 4  

NASA Technical Reports Server (NTRS)

The design of a high speed transport aircraft using the oblique wing concept as a part of the High Speed Civil Transport (HSCT) aircraft study is the Leading Edge 250 capable of travelling at Mach 4 with 250 passengers and has a 6,500 nautical mile range. Its innovation lies within its use of the unconventional oblique wing to provide efficient flight at any Mach number. Wave drag is kept to a minimum at high speed, while high lift is attained during critical takeoff and landing maneuvers by varying the sweep of the wing.

Schmidt, Andre; Moore, Peri; Nguyen, Dan; Oganesyan, Petros; Palmer, Charles

1988-01-01

9

Aerodynamic derivatives for an oblique wing aircraft estimated from flight data by using a maximum likelihood technique  

NASA Technical Reports Server (NTRS)

There are several practical problems in using current techniques with five degree of freedom equations to estimate the stability and control derivatives of oblique wing aircraft from flight data. A technique was developed to estimate these derivatives by separating the analysis of the longitudinal and lateral directional motion without neglecting cross coupling effects. Although previously applied to symmetrical aircraft, the technique was not expected to be adequate for oblique wing vehicles. The application of the technique to flight data from a remotely piloted oblique wing aircraft is described. The aircraft instrumentation and data processing were reviewed, with particular emphasis on the digital filtering of the data. A complete set of flight determined stability and control derivative estimates is presented and compared with predictions. The results demonstrated that the relatively simple approach developed was adequate to obtain high quality estimates of the aerodynamic derivatives of such aircraft.

Maine, R. E.

1978-01-01

10

Oblique-wing research airplane motion simulation with decoupling control laws  

NASA Technical Reports Server (NTRS)

A large piloted vertical motion simulator was used to assess the performance of a preliminary decoupling control law for an early version of the F-8 oblique wing research demonstrator airplane. Evaluations were performed for five discrete flight conditions, ranging from low-altitude subsonic Mach numbers to moderate-altitude supersonic Mach numbers. Asymmetric sideforce as a function of angle of attack was found to be the primary cause of both the lateral acceleration noted in pitch and the tendency to roll into left turns and out of right turns. The flight control system was shown to be effective in generally decoupling the airplane and reducing the lateral acceleration in pitch maneuvers.

Kempel, Robert W.; Mc Neill, Walter E.; Maine, Trindel A.

1988-01-01

11

Oblique wing transonic transport configuration development  

NASA Technical Reports Server (NTRS)

Studies of transport aircraft designed for boom-free supersonic flight show the variable sweep oblique wing to be the most efficient configuration for flight at low supersonic speeds. Use of this concept leads to a configuration that is lighter, quieter, and more fuel efficient than symmetric aircraft designed for the same mission. Aerodynamic structural, weight, aeroelastic and flight control studies show the oblique wing concept to be technically feasible. Investigations are reported for wing planform and thickness, pivot design and weight estimation, engine cycle (bypass ratio), and climb, descent and reserve fuel. Results are incorporated into a final configuration. Performance, weight, and balance characteristics are evaluated. Flight control requirements are reviewed, and areas in which further research is needed are identified.

1977-01-01

12

F-8 oblique wing structural feasibility study  

NASA Technical Reports Server (NTRS)

The feasibility of fitting a rotating oblique wing on an F-8 aircraft to produce a full scale manned prototype capable of operating in the transonic and supersonic speed range was investigated. The strength, aeroelasticity, and fatigue life of such a prototype are analyzed. Concepts are developed for a new wing, a pivot, a skewing mechanism, control systems that operate through the pivot, and a wing support assembly that attaches in the F-8 wing cavity. The modification of the two-place NTF-8A aircraft to the oblique wing configuration is discussed.

Koltko, E.; Katz, A.; Bell, M. A.; Smith, W. D.; Lauridia, R.; Overstreet, C. T.; Klapprott, C.; Orr, T. F.; Jobe, C. L.; Wyatt, F. G.

1975-01-01

13

Transonic wind tunnel test of a 14 percent thick oblique wing  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted at the ARC 11- by 11-Foot Transonic Wind Tunnel as part of the Oblique Wing Research Aircraft Program to study the aerodynamic performance and stability characteristics of a 0.087-scale model of an F-8 airplane fitted with an oblique wing designed by Rockwell International. The 10.3 aspect ratio, straight-tapered wing of 0.14 thickness/chord ratio was tested at two different mounting heights above the fuselage. Additional tests were conducted to assess low-speed behavior with and without flaps, aileron effectiveness at representative flight conditions, and transonic drag divergence with 0 degree wing sweep. Longitudinal stability data were obtained at sweep angles of 0, 30, 45, 60, and 65 degrees, at Mach numbers ranging from 0.25 to 1.40. Test Reynolds numbers varied from 3.2 to 6.6 x 10 exp 6/ft. and angle of attack ranged from -5 to +18 degrees. Most data were taken at zero sideslip, but a few runs were at sideslip angles of +/- 5 degrees. The raised wing position proved detrimental overall, although side force and yawing moment were reduced at some conditions. Maximum lift coefficient with the flaps deflected was found to fall short of the value predicted in the preliminary design document. The performance and trim characteristics of the present wing are generally inferior to those obtained for a previously tested wing designed at ARC.

Kennelly, Robert A., Jr.; Kroo, Ilan M.; Strong, James M.; Carmichael, Ralph L.

1990-01-01

14

Decoupling Control For Oblique-Wing Airplane  

NASA Technical Reports Server (NTRS)

Technical memorandum proposes procedure for mathematical synthesis of control signals proportional to commanded deflections of rudder, elevators, and ailerons of oblique-wing airplane. Procedure designed to generate signals compensating for aerodynamical and inertial cross-coupling among yawing, pitching, and rolling motions. Control interactions decoupled by feedforward and feedback.

Kempel, Robert W.; Pahle, Joseph W.; Alag, Gurbux S.

1992-01-01

15

Two-stage earth-to-orbit transport with translating oblique wings for booster recovery  

NASA Technical Reports Server (NTRS)

A two-stage earth-to-orbit transport includes an orbiter vehicle and a pair of boosters, each having a depolyable oblique wing located along a longitudinal axis of the booster. The wing is deployed in an oblique disposition in supersonic and hypersonic speeds, and disposed at 90.degree. for subsonic speeds encountered during entry. The oblique wing is driven axially and rotated by means of a turret mounted on rails.

MacConochie, Ian O. (Inventor); Briener, Charles A. (Inventor)

1991-01-01

16

Aircraft fire safety research  

NASA Technical Reports Server (NTRS)

During the past 15 years, very significant progress has been made toward enhancing aircraft fire safety in both normal and hostile (combat) operational environments. Most of the major aspects of the aircraft fire safety problem are touched upon here. The technology of aircraft fire protection, although not directly applicable in all cases to spacecraft fire scenarios, nevertheless does provide a solid foundation to build upon. This is particularly true of the extensive research and testing pertaining to aircraft interior fire safety and to onboard inert gas generation systems, both of which are still active areas of investigation.

Botteri, Benito P.

1987-01-01

17

Aircraft as Research Tools  

NASA Technical Reports Server (NTRS)

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.

1999-01-01

18

Effect of wing flexibility on the experimental aerodynamic characteristics of an oblique wing  

NASA Technical Reports Server (NTRS)

A solid-aluminum oblique wing was designed to deflect considerably under load so as to relieve the asymmetric spanwise stalling that is characteristic of this type of wing by creating washout on the trailing wing panel and washin on the leading wing panel. Experimental forces, and pitching, rolling and yawing moments were measured with the wing mounted on a body of revolution. In order to vary the dynamic pressure, measurements were made at several unit Reynolds numbers, and at Mach numbers. The wing was investigated when unswept (at subsonic Mach numbers only) and when swept 45 deg, 50 deg, and 60 deg. The wing was straight tapered in planform, had an aspect ratio of 7.9 (based on the unswept span), and a profile with a maximum thickness of 4 percent chord. The results substantiate the concept that an oblique wing designed with the proper amount of flexibility self relieves itself of asymmetric spanwise stalling and the associated nonlinear moment curves.

Hopkins, E. J.; Yee, S. C.

1977-01-01

19

X-29: Research Aircraft  

NASA Technical Reports Server (NTRS)

A preliminary look at the Ames Dryden Flight Research Center in the context of the X-29 aircraft is provided. The uses of the X-29's 30 deg forward swept wing are examined. The video highlights the historical development of the forward swept wing, and its unique blend of speed, agility, and slow flight potential. The central optimization of the wing, the forward canard, and the rear flaps by an onboard flight computer is also described.

1991-01-01

20

Aileron and Krueger nose flap effectiveness measured on an oblique wing  

NASA Technical Reports Server (NTRS)

The effects that deflection of conventional ailerons have on the lateral/directional characteristics of an oblique wing mounted on top of a body of revolution were measured. The wing had an aspect ratio of 6 (based on the unswept wing span) and was tested at various sweep angles ranging from 0 deg to 60 deg. Krueger nose flaps mounted on drooped-nose flaps were investigated on the downstream wing panel (for sweep angles of 45 deg and 60 deg) in an attempt to create more symmetrical spanwise wing stalling at high lift coefficients. The tests were conducted over a Mach number range of 0.25 to 1.4 and an angle-of-attack range from -3 deg to 28 deg. With the oblique wing in the swept position, considerable difference in the aileron effectiveness was measured for positive or negative differential aileron deflections. With the wing swept 45 deg at a Mach number of 0.8 and above, an extension of the span of the Krueger nose flaps on the downstream wing panel did not improve the linearity of the pitching-, rolling-, and yawing-moment curves.

Hopkins, E. J.; Lovette, G. H.

1977-01-01

21

Pilotless Aircraft Research Division  

NASA Technical Reports Server (NTRS)

Technician William Ferguson adjusts coupling on typical NACA D4 automatic control research missile with double Deacon booster, August 18, 1950. Joseph Shortal noted that a new research authorization (RA 1525) was issued on September 29, 1948 'to study various automatic stabilization systems for pilotless aircraft.' Earlier research had revealed aerodynamic control problems at speeds beyond Mach 1. The first two development missiles in this research program were launched in April 1949; the first stabilized missile on May 24, 1949. That flight was successful and 'verified the wing-tip aileron control system, the adaptation of the gyro-actuated control to supersonic flight, and a method for calculating rolling response.' 'A typical D4 missile is shown on the launcher.... This particular missile was launched August 1950, by which time the booster had been changed to a double-Deacon System to obtain higher speeds. The D4 missile configuration was also found to be a desirable one from pitch and yaw considerations in later flights. Its general configuration was followed later in the design of the Navy-Martin Bullpup air-to-ground guided missile.' Excerpts from Joseph Shortal's history of Wallops Station.

1950-01-01

22

A comparison of the experimental aerodynamic characteristics of an oblique wing with those of a swept wing. [in the Ames 6 by 6 foot wind tunnel  

NASA Technical Reports Server (NTRS)

Force and moment characteristics were measured for two trapezoidal oblique wings and a conventional swept wing mounted on a body of revolution at Mach numbers from 0.25 to 2.0. Both oblique wings had the same planform, but differed in profile and flexibility. One of the oblique wings was made of solid steel and had a maximum thickness-to-chord ratio of 4 percent. The other wing was built up by taking an aluminum wing and adding epoxy material to the upper surface to increase the maximum thickness-to-chord ratio to 8.2 percent. The aspect ratio for both oblique wings when swept 45 deg, and for the swept wing with 45 deg of sweep, was 4.1. Data were obtained at unit Reynolds numbers ranging from 3.3 to 8.2 million per meter and were compared with previously obtained data on the aluminum wing before it was built up with epoxy. Wing flexibility designed into the aluminum and built-up aluminum oblique wings increased the range of lift coefficients from 0.30 to 0.70 over which the pitching-moment curves were linear. However, flexibility did not improve the linearity of the rolling-moment curves and produced sizable side forces. At a Mach number of 0.95, the trapezoidal oblique wing had little or no improvement in the lift/drag ratios over those for a conventional swept wing of the same aspect ratio, sweep, and profile.

Hopkins, E. J.; Yee, S. C.

1977-01-01

23

Effect of Krueger nose flaps on the experimental force and moment characteristics of an oblique wing  

NASA Technical Reports Server (NTRS)

Experimental force and moment data are presented for an oblique wing mounted on a body of revolution and equipped with Krueger type nose flaps. The effectiveness of these flaps in making the moment curves more linear by controlling the flow separation on the downstream wing panel at high lift coefficients was determined. The investigation of the effects of the Krueger flaps covered two cases: (1) use of the flaps on the downstream wing panel only and (2) use of the flaps on both wing panels. For part of the tests, the Krueger flaps were mounted on nose flaps that were drooped either 5 deg or 10 deg. The wing was elliptical in planform, had an aspect ratio of 6.0 (based on the unswept span) and was tested at sweep angles of 0, 45 deg, and 50 deg. The Mach-number range covered was from 0.25 to 0.95. It was found that the most effective arrangement of the Krueger flaps for making the pitching-, rolling-, and yawing-moment curves more linear at high lift coefficients was having the Krueger flaps mounted on the nose flaps drooped 5 deg and only on the downstream wing panel.

Hopkins, E. J.; Lovette, G. H.

1976-01-01

24

Airborne Subscale Transport Aircraft Research Testbed: Aircraft Model Development.  

National Technical Information Service (NTIS)

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 env...

T. L. Jordan W. M. Langford J. S. Hill

2005-01-01

25

Pressure-sensitive paint measurements on a supersonic high-sweep oblique wing model. [conducted in the NASA Ames 9- by 7-ft Supersonic Wind Tunnel  

NASA Technical Reports Server (NTRS)

The pressure-sensitive paint method was used in the test of a high-sweep oblique wing model, conducted in the NASA Ames 9- by 7-ft Supersonic Wind Tunnel. Surface pressure data was acquired from both the luminescent paint and conventional pressure taps at Mach numbers between M = 1.6 and 2.0. In addition, schlieren photographs of the outer flow were used to determine the location of shock waves impinging on the model. The results show that the luminescent pressure-sensitive paint can capture both global and fine features of the static surface pressure field. Comparison with conventional pressure tap data shows good agreement between the two techniques, and that the luminescent paint data can be used to make quantitative measurements of the pressure changes over the model surface. The experiment also demonstrates the practical considerations and limitations that arise in the application of this technique under supersonic flow conditions in large-scale facilities, as well as the directions in which future research is necessary in order to make this technique a more practical wind-tunnel testing tool.

McLachlan, B. G.; Bell, J. H.; Park, H.; Kennelly, R. A.; Schreiner, J. A.; Smith, S. C.; Strong, J. M.; Gallery, J.; Gouterman, M.

1995-01-01

26

NASA aircraft trailing vortex research  

NASA Technical Reports Server (NTRS)

A brief description is given of NASA's comprehensive program to study the aircraft trailing vortex problem. Wind tunnel experiments are used to develop the detailed processes of wing tip vortex formation and explore different means to either prevent trailing vortices from forming or induce early break-up. Flight tests provide information on trailing vortex system behavior behind large transport aircraft, both near the ground, as in the vicinity of the airport, and at cruise/holding pattern altitudes. Results from some flight tests are used to show how pilots might avoid the dangerous areas when flying in the vicinity of large transport aircraft. Other flight tests will be made to verify and evaluate trailing vortex elimination schemes developed in the model tests. Laser Doppler velocimeters being developed for use in the research program and to locate and measure vortex winds in the airport area are discussed. Field tests have shown that the laser Doppler velocimeter measurements compare well with those from cup anemometers.

Mcgowan, W. A.

1971-01-01

27

Subsonic Ultra Green Aircraft Research  

NASA Technical Reports Server (NTRS)

This Final Report summarizes the work accomplished by the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team in Phase 1, which includes the time period of October 2008 through March 2010. The team consisted of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, and Georgia Tech. The team completed the development of a comprehensive future scenario for world-wide commercial aviation, selected baseline and advanced configurations for detailed study, generated technology suites for each configuration, conducted detailed performance analysis, calculated noise and emissions, assessed technology risks, and developed technology roadmaps. Five concepts were evaluated in detail: 2008 baseline, N+3 reference, N+3 high span strut braced wing, N+3 gas turbine battery electric concept, and N+3 hybrid wing body. A wide portfolio of technologies was identified to address the NASA N+3 goals. Significant improvements in air traffic management, aerodynamics, materials and structures, aircraft systems, propulsion, and acoustics are needed. Recommendations for Phase 2 concept and technology projects have been identified.

Bradley, Marty K.; Droney, Christopher K.

2011-01-01

28

The F-18 systems research aircraft facility  

NASA Technical Reports Server (NTRS)

To help ensure that new aerospace initiatives rapidly transition to competitive U.S. technologies, NASA Dryden Flight Research Facility has dedicated a systems research aircraft facility. The primary goal is to accelerate the transition of new aerospace technologies to commercial, military, and space vehicles. Key technologies include more-electric aircraft concepts, fly-by-light systems, flush airdata systems, and advanced computer architectures. Future aircraft that will benefit are the high-speed civil transport and the National AeroSpace Plane. This paper describes the systems research aircraft flight research vehicle and outlines near-term programs.

Sitz, Joel R.

1992-01-01

29

Technical Seminar: "Progress in Aircraft Noise Research"""  

NASA Video Gallery

Advances in aircraft noise research can be attributed to the development of new technologies and sustained collaboration with industry, universities and government organizations. Emphasis has been ...

30

Airborne Subscale Transport Aircraft Research Testbed: Aircraft Model Development  

NASA Technical Reports Server (NTRS)

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.

Jordan, Thomas L.; Langford, William M.; Hill, Jeffrey S.

2005-01-01

31

Supersonic cruise aircraft research: An annotated bibliography  

NASA Technical Reports Server (NTRS)

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.

Tuttle, M. H.

1980-01-01

32

Effect of drooped-nose flaps on the experimental force and moment characteristics of an oblique wing  

NASA Technical Reports Server (NTRS)

Six-component experimental force and moment data are presented for a low aspect ratio, oblique wing equipped with drooped-nose flaps and mounted on top of a body of revolution. These flaps were investigated on the downstream wing panel with the nose drooped 5 deg, 10 deg, 20 deg, and 30 deg, and on both wing panels with the nose drooped 30 deg. It was to determine if such flaps would make the moment curves more linear by controlling the flow separation on the downstream wing panel at high lift coefficients. The wing was elliptical in planform and had an aspect ratio of 6.0 (based on the unswept wing span). The wing was tested at sweep angles of 45 deg and 50 deg throughout the Mach number range from 0.25 to 0.95. The drooped-nose flaps alone were not effective in making the moment curves more linear; however, a previous study showed that Kruger nose flaps improved the linearity of the moment curves when the Kruger flaps were used on only the downstream wing panel equipped with drooped-nose flaps deflected 5 deg.

Hopkins, E. J.; Lovette, G. H.

1976-01-01

33

The XV-15 tilt rotor research aircraft  

NASA Technical Reports Server (NTRS)

The design characteristics of the XV-15 Tilt rotor research aircraft are presented. Particular attention is given to the following: control system; conversion system; and propulsion system. Flight test results are also reported.

Dugan, D. C.; Erhart, R. G.; Schroers, L. G.

1980-01-01

34

The NASA aircraft icing research program  

NASA Technical Reports Server (NTRS)

The objective of the NASA aircraft icing research program is to develop and make available to industry icing technology to support the needs and requirements for all-weather aircraft designs. Research is being done for both fixed wing and rotary wing applications. The NASA program emphasizes technology development in two areas, advanced ice protection concepts and icing simulation. Reviewed here are the computer code development/validation, icing wind tunnel testing, and icing flight testing efforts.

Shaw, Robert J.; Reinmann, John J.

1990-01-01

35

NASA's Research in Aircraft Vulnerability Mitigation  

NASA Technical Reports Server (NTRS)

Since its inception in 1958, the National Aeronautics and Space Administration s (NASA) role in civil aeronautics has been to develop high-risk, high-payoff technologies to meet critical national aviation challenges. Following the events of Sept. 11, 2001, NASA recognized that it now shared the responsibility for improving homeland security. The NASA Strategic Plan was modified to include requirements to enable a more secure air transportation system by investing in technologies and collaborating with other agencies, industry, and academia. NASA is conducting research to develop and advance innovative and commercially viable technologies that will reduce the vulnerability of aircraft to threats or hostile actions, and identify and inform users of potential vulnerabilities in a timely manner. Presented in this paper are research plans and preliminary status for mitigating the effects of damage due to direct attacks on civil transport aircraft. The NASA approach to mitigation includes: preventing loss of an aircraft due to a hit from man-portable air defense systems; developing fuel system technologies that prevent or minimize in-flight vulnerability to small arms or other projectiles; providing protection from electromagnetic energy attacks by detecting directed energy threats to aircraft and on/off-board systems; and minimizing the damage due to high-energy attacks (explosions and fire) by developing advanced lightweight, damage-resistant composites and structural concepts. An approach to preventing aircraft from being used as weapons of mass destruction will also be discussed.

Allen, Cheryl L.

2005-01-01

36

Rotor systems research aircraft simulation mathematical model  

NASA Technical Reports Server (NTRS)

An analytical model developed for evaluating and verifying advanced rotor concepts is discussed. The model was used during in both open loop and real time man-in-the-loop simulation during the rotor systems research aircraft design. Future applications include: pilot training, preflight of test programs, and the evaluation of promising concepts before their implementation on the flight vehicle.

Houck, J. A.; Moore, F. L.; Howlett, J. J.; Pollock, K. S.; Browne, M. M.

1977-01-01

37

Overview of high performance aircraft propulsion research  

NASA Technical Reports Server (NTRS)

The overall scope of the NASA Lewis High Performance Aircraft Propulsion Research Program is presented. High performance fighter aircraft of interest include supersonic flights with such capabilities as short take off and vertical landing (STOVL) and/or high maneuverability. The NASA Lewis effort involving STOVL propulsion systems is focused primarily on component-level experimental and analytical research. The high-maneuverability portion of this effort, called the High Alpha Technology Program (HATP), is part of a cooperative program among NASA's Lewis, Langley, Ames, and Dryden facilities. The overall objective of the NASA Inlet Experiments portion of the HATP, which NASA Lewis leads, is to develop and enhance inlet technology that will ensure high performance and stability of the propulsion system during aircraft maneuvers at high angles of attack. To accomplish this objective, both wind-tunnel and flight experiments are used to obtain steady-state and dynamic data, and computational fluid dynamics (CFD) codes are used for analyses. This overview of the High Performance Aircraft Propulsion Research Program includes a sampling of the results obtained thus far and plans for the future.

Biesiadny, Thomas J.

1992-01-01

38

Aircraft Advanced Materials Research and Development Program Plan.  

National Technical Information Service (NTIS)

This report describes the FAA research and development plan in Aircraft Advanced Materials and Structures. The Aircraft Advanced Materials Research and Development Plan identifies technology issues that must be addressed to accomplish the FAA mission.

P. Shyprykevich J. Soderquist

1994-01-01

39

High temperature aircraft research furnace facilities  

NASA Technical Reports Server (NTRS)

Focus is on the design, fabrication, and development of the High Temperature Aircraft Research Furnace Facilities (HTARFF). The HTARFF was developed to process electrically conductive materials with high melting points in a low gravity environment. The basic principle of operation is to accurately translate a high temperature arc-plasma gas front as it orbits around a cylindrical sample, thereby making it possible to precisely traverse the entire surface of a sample. The furnace utilizes the gas-tungsten-arc-welding (GTAW) process, also commonly referred to as Tungsten-Inert-Gas (TIG). The HTARFF was developed to further research efforts in the areas of directional solidification, float-zone processing, welding in a low-gravity environment, and segregation effects in metals. The furnace is intended for use aboard the NASA-JSC Reduced Gravity Program KC-135A Aircraft.

Smith, James E., Jr.; Cashon, John L.

1992-01-01

40

Aircraft Turbine Engine Control Research at NASA Glenn Research Center  

NASA Technical Reports Server (NTRS)

This paper provides an overview of the aircraft turbine engine control research at the NASA Glenn Research Center (GRC). A brief introduction to the engine control problem is first provided with a description of the state-of-the-art control law structure. A historical aspect of engine control development since the 1940s is then provided with a special emphasis on the contributions of GRC. With the increased emphasis on aircraft safety, enhanced performance, and affordability, as well as the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch (CDB) at GRC is leading and participating in various projects to develop advanced propulsion controls and diagnostics technologies that will help meet the challenging goals of NASA Aeronautics Research Mission programs. The rest of the paper provides an overview of the various CDB technology development activities in aircraft engine control and diagnostics, both current and some accomplished in the recent past. The motivation for each of the research efforts, the research approach, technical challenges, and the key progress to date are summarized.

Garg, Sanjay

2013-01-01

41

Recent Progress in Aircraft Noise Research  

NASA Technical Reports Server (NTRS)

An overview of the acoustics research at NASA under the Subsonic Fixed Wing project is given. The presentation describes the rationale behind the noise reduction goals of the project in the context of the next generation air transportation system, and the emphasis placed on achieving these goals through a combination of the in-house and collaborative efforts with industry, universities and other government agencies. The presentation also describes the in-house research plan which is focused on the development of advanced noise and flow diagnostic techniques, next generation noise prediction tools, and novel noise reduction techniques that are applicable across a wide range of aircraft.

Envia, Edmane; Thomas, Russell

2007-01-01

42

Research Aircraft Helps Scientists Study Troposphere  

NASA Astrophysics Data System (ADS)

A newly developed advanced research aircraft will allow researchers to directly study the atmosphere for extended periods of time at altitudes that approach the troposphere-stratosphere boundary. The plane, called the High-performance Instrumented Airborne Platform for Environmental Research (HIAPER), can carry nearly 3000 kilograms of scientific instrumentation, reach an altitude of more than 15,500 meters, and cruise without refueling for over 11,200 kilometers. Owned by the U.S. National Science Foundation (NSF) and operated by the National Center for Atmospheric Research (NCAR) in Boulder, Colo., HIAPER will be used to collect detailed information on the meteorology of the upper edges of hurricanes and thunderstorms, high altitude chemical reactions that are believed to affect climate, and other research concerns.

Kumar, Mohi

2006-03-01

43

Requirement for simulation in V/STOL research aircraft programs  

NASA Technical Reports Server (NTRS)

The application of flight simulation to aircraft design and development is discussed. The general stages of aircraft development are defined. The application of flight simulation to the following projects is reported: (1) the development and flight research of the Augmented Jet-Flap STOL research aircraft and (2) design studies of advanced VTOL research aircraft. It is stated that the simulation projects proved significant in helping establish criteria for the aircraft design and in facilitating the study of problems associated with new flight profiles, new methods of control, and special emergency conditions.

Quigley, H. C.; Holzhauser, C. A.

1974-01-01

44

X-1 research aircraft landing on lakebed  

NASA Technical Reports Server (NTRS)

The first of the rocket-powered research aircraft, the X-1 (originally designated the XS-1), was a bullet-shaped airplane that was built by the Bell Aircraft Company for the US Air Force and the National Advisory Committee on Aeronautics (NACA). The mission of the X-1 was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier'. The first of the three X-1s was glide-tested at Pinecastle Air Force Base, FL, in early 1946. The first powered flight of the X-1 was made on Dec. 9, 1946, at Edwards Air Force Base with Chalmers Goodlin, a Bell test pilot, at the controls. On Oct. 14, 1947, with USAF Captain Charles 'Chuck' Yeager as pilot, the aircraft flew faster than the speed of sound for the first time. Captain Yeager ignited the four-chambered XLR-11 rocket engines after being air-launched from under the bomb bay of a B-29 at 21,000 ft. The 6,000-lbthrust ethyl alcohol/liquid oxygen burning rockets, built by Reaction Motors, Inc., pushed him up to a speed of 700 mph in level flight. Captain Yeager was also the pilot when the X-1 reached its maximum speed of 957 mph. Another USAF pilot. Lt. Col. Frank Everest, Jr., was credited with taking the X-1 to its maximum altitude of 71,902 ft. Eighteen pilots in all flew the X-1s. The number three plane was destroyed in a fire before ever making any powered flights. A single-place monoplane, the X-1 was 31 ft long, 10 ft high, and had a wingspan of 29 ft. It weighed 4,900 lb and carried 8,200 lb of fuel. It had a flush cockpit with a side entrance and no ejection seat. This roughly 30-second video clip shows the X-1 landing on Rogers Dry Lakebed followed by the safety chase aircraft.

1947-01-01

45

Rotor systems research aircraft predesign study. Volume 3: Predesign report  

NASA Technical Reports Server (NTRS)

The features of two aircraft designs were selected to be included in the single RSRA configuration. A study was conducted for further preliminary design and a more detailed analysis of development plans and costs. An analysis was also made of foreseeable technical problems and risks, identification of parallel research which would reduce risks and/or add to the basic capability of the aircraft, and a draft aircraft specification.

Schmidt, S. A.; Linden, A. W.

1972-01-01

46

The outlook for advanced transport aircraft  

NASA Technical Reports Server (NTRS)

The technological advances most likely to contribute to advanced aircraft designs and the efficiency, performance, and financial considerations driving the development directions for new aircraft are reviewed. Fuel-efficiency is perceived as the most critical factor for any new aircraft or component design, with most gains expected to come in areas of propulsion, aerodynamics, configurations, structural designs and materials, active controls, digital avionics, laminar flow control, and air-traffic control improvements. Any component area offers an efficiency improvement of 3-12%, with a maximum of 50% possible with a 4000 m range aircraft. Advanced turboprops have potential applications in short and medium haul subsonic aircraft, while a fuel efficient SST may be possible by the year 2000. Further discussion is devoted to the pivoted oblique wing aircraft, lightweight structures, and the necessity for short payback times.

Leavens, J. M., Jr.; Schaufele, R. D.; Jones, R. T.; Steiner, J. E.; Beteille, R.; Titcomb, G. A.; Coplin, J. F.; Rowe, B. H.; Lloyd-Jones, D. J.; Overend, W. J.

1982-01-01

47

Research and Technology for Aircraft Fire Protection.  

National Technical Information Service (NTIS)

The development of high-performance, advanced aircraft introduces new problems in fire safety. Insufficient knowledge and experience exist to establish accurately the degree of hazard that results from such considerations as aerodynamic heating of surface...

G. T. Beery B. P. Botteri

1966-01-01

48

Walter C. Williams Research Aircraft Integration Facility (RAIF)  

NASA Technical Reports Server (NTRS)

The NASA-Dryden Integrated Test Facility (ITF), also known as the Walter C. Williams Research Aircraft Integration Facility (RAIF), provides an environment for conducting efficient and thorough testing of advanced, highly integrated research aircraft. Flight test confidence is greatly enhanced by the ability to qualify interactive aircraft systems in a controlled environment. In the ITF, each element of a flight vehicle can be regulated and monitored in real time as it interacts with the rest of the aircraft systems. Testing in the ITF is accomplished through automated techniques in which the research aircraft is interfaced to a high-fidelity real-time simulation. Electric and hydraulic power are also supplied, allowing all systems except the engines to function as if in flight. The testing process is controlled by an engineering workstation that sets up initial conditions for a test, initiates the test run, monitors its progress, and archives the data generated. The workstation is also capable of analyzing results of individual tests, comparing results of multiple tests, and producing reports. The computers used in the automated aircraft testing process are also capable of operating in a stand-alone mode with a simulation cockpit, complete with its own instruments and controls. Control law development and modification, aerodynamic, propulsion, guidance model qualification, and flight planning -- functions traditionally associated with real-time simulation -- can all be performed in this manner. The Remotely Augmented Vehicles (RAV) function, now located in the ITF, is a mainstay in the research techniques employed at Dryden. This function is used for tests that are too dangerous for direct human involvement or for which computational capacity does not exist onboard a research aircraft. RAV provides the researcher with a ground-based computer that is radio linked to the test aircraft during actual flight. The Ground Vibration Testing (GVT) system, formerly housed in the Thermostructural Laboratory, now also resides in the ITF. In preparing a research aircraft for flight testing, it is vital to measure its structural frequencies and mode shapes and compare results to the models used in design analysis. The final function performed in the ITF is routine aircraft maintenance. This includes preflight and post-flight instrumentation checks and the servicing of hydraulics, avionics, and engines necessary on any research aircraft. Aircraft are not merely moved to the ITF for automated testing purposes but are housed there throughout their flight test programs.

1996-01-01

49

X-38 research aircraft deorbit - computer animation  

NASA Technical Reports Server (NTRS)

In the mid-1990's researchers at the NASA Dryden Flight Research Center, Edwards, California, and Johnson Space Center in Houston, Texas, began working actively with the sub-scale X-38 prototype crew return vehicle (CRV). This was an unpiloted lifting body designed at 80 percent of the size of a projected emergency crew return vehicle for the International Space Station. The X-38 and the actual CRV are patterned after a lifting-body shape first employed in the Air Force X-23 (SV-5) program in the mid-1960's and the Air Force-NASA X-24A lifting-body project in the early to mid-1970's. Built by Scaled Composites, Inc., in Mojave, California, and outfitted with avionics, computer systems, and other hardware at Johnson Space Center, two X-38 aircraft were involved in flight research at Dryden beginning in July of 1997. Before that, however, Dryden conducted some 13 flights at a drop zone near California City, California. These tests were done with a 1/6-scale model of the X-38 to test the parafoil concept that would be employed on the X-38 and the actual CRV. The basic concept is that the actual CRV will use an inertial navigation system together with the Global Positioning System of satellites to guide it from the International Space Station into the earth's atmosphere. A deorbit engine module will redirect the vehicle from orbit into the atmosphere where a series of parachutes and a parafoil will deploy in sequence to bring the vehicle to a landing, possibly in a field next to a hospital. Flight research at NASA Dryden for the X-38 began with an unpiloted captive carry flight in which the vehicle remained attached to its future launch vehicle, the Dryden B-52 008. There were four captive flights in 1997 and three in 1998, plus the first drop test on March 12, 1998, using the parachutes and parafoil. Further captive and drop tests occurred in 1999. Although the X-38 landed safely on the lakebed at Edwards after the March 1998 drop test, there had been some problems with the parafoil. Intermediate parafoil tests at the Army Yuma Proving Grounds in Arizona enabled the project to resolve these problems and resume flight research. In the drop tests, the X-38 vehicles have been autonomous after airlaunch from the B-52. After they deploy the parafoil, they have remained autonomous, but there is also a manual mode that allows control from the ground. The X-38 vehicles (designated V131 and V132) are each 24.5 feet long. The actual CRV to be flown in space is expected to be 30 feet long. This is short 16-second computer animation clip showing the X-38 vehicle performing a deorbit engine burn, bringing the vehicle around 180 degrees and then jettisoning the solid rocket pack to reduce its re-entry weight.

1997-01-01

50

Aircraft research and development trends in the US and USSR  

NASA Technical Reports Server (NTRS)

Research and development related to aircraft has shown significant progress in both the U.S. and the USSR. In some cases, the indications are that technological advances have resulted in new aircraft concepts and, in other cases, there are indications of particular national needs or objectives that have driven the required research and development to meet the need. The progression of aircraft development tends to reflect factors other than technology such as the political atmosphere, the world environment, and other contending national objectives. The trends in aircraft research and development in the U.S. and USSR will be traced from the early 1900's and, in a time-frame manner, will be related to other influencing factors.

Spearman, M. L.

1986-01-01

51

V/STOL tilt rotor aircraft study. Volume 2: Preliminary design of research aircraft  

NASA Technical Reports Server (NTRS)

A preliminary design study was conducted to establish a minimum sized, low cost V/STOL tilt-rotor research aircraft with the capability of performing proof-of-concept flight research investigations applicable to a wide range of useful military and commercial configurations. The analysis and design approach was based on state-of-the-art methods and maximum use of off-the-shelf hardware and systems to reduce development risk, procurement cost and schedules impact. The rotors to be used are of 26 foot diameter and are the same as currently under construction and test as part of NASA Tilt-Rotor Contract NAS2-6505. The aircraft has a design gross weight of 12,000 lbs. The proposed engines to be used are Lycoming T53-L-13B rated at 1550 shaft horsepower which are fully qualified. A flight test investigation is recommended which will determine the capabilities and limitations of the research aircraft.

1972-01-01

52

NASA Glenn's Contributions to Aircraft Engine Noise Research  

NASA Technical Reports Server (NTRS)

This report reviews all engine noise research conducted at the NASA Glenn Research Center over the past 70 years. This report includes a historical perspective of the Center and the facilities used to conduct the research. Major noise research programs are highlighted to show their impact on industry and on the development of aircraft noise reduction technology. Noise reduction trends are discussed, and future aircraft concepts are presented. Since the 1960s, research results show that the average perceived noise level has been reduced by about 20 decibels (dB). Studies also show that, depending on the size of the airport, the aircraft fleet mix, and the actual growth in air travel, another 15 to 17 dB reduction will be required to achieve NASA's long-term goal of providing technologies to limit objectionable noise to the boundaries of an average airport.

Huff, Dennis L.

2013-01-01

53

Development of In-Flight Simulation Aircraft for Research and Training Applications in UK (United Kingdom).  

National Technical Information Service (NTIS)

The objectives and the aircraft experimental system for the Vectored thrust Aircraft Advanced Flight Control (VAAC) research program are discussed. The VAAC program studies control laws, displays and cockpit controls for advanced STOL aircraft. The object...

O. P. Nicholas J. A. Giles D. A. Williams

1986-01-01

54

Design and physical characteristics of the Transonic Aircraft Technology (TACT) research aircraft  

NASA Technical Reports Server (NTRS)

The Transonic Aircraft Technology (TACT) research program provided data necessary to verify aerodynamic concepts, such as the supercritical wing, and to gain the confidence required for the application of such technology to advanced high performance aircraft. An F-111A aircraft was employed as the flight test bed to provide full scale data. The data were correlated extensively with predictions based on data obtained from wind tunnel tests. An assessment of the improvement afforded at transonic speeds in drag divergence, maneuvering performance, and airplane handling qualities by the use of the supercritical wing was included in the program. Transonic flight and wind tunnel testing techniques were investigated, and specific research technologies evaluated were also summarized.

Painter, W. D.; Caw, L. J.

1978-01-01

55

Flight Testing the Rotor Systems Research Aircraft (RSRA)  

NASA Technical Reports Server (NTRS)

In the late 1960s, efforts to advance the state-of-the-art in rotor systems technology indicated a significant gap existed between our ability to accurately predict the characteristics of a complex rotor system and the results obtained through flight verification. Even full scale wind tunnel efforts proved inaccurate because of the complex nature of a rotating, maneuvering rotor system. The key element missing, which prevented significant advances, was our inability to precisely measure the exact rotor state as a function of time and flight condition. Two Rotor Research Aircraft (RSRA) were designed as pure research aircraft and dedicated rotor test vehicles whose function is to fill the gap between theory, wind tunnel testing, and flight verification. The two aircraft, the development of the piloting techniques required to safely fly the compound helicopter, the government flight testing accomplished to date, and proposed future research programs.

Hall, G. W.; Merrill, R. K.

1983-01-01

56

AIRCRAFT  

Microsoft Academic Search

The United States aircraft industry continues to be a critical element of economic, political, and military power. It is second to none in export dollars and fills a place that cannot be substituted by any other industry. The U.S. aircraft industry was once dominant in the global aircraft market, but Europe has now reached a level of parity in commercial

Gheorge Catrina; Conway Ellers; Dave Hersh; John Krieger; Randy McFadden; Matt Mulhern; Mark Steenberg; Mike Steinmetz; Col Larry Franks

57

Some historical trends in the research and development of aircraft  

NASA Technical Reports Server (NTRS)

A survey of some trends in aircraft design was made in an effort to determine the relation between research, development, test, and evaluation (RDT and E) and aircraft mission capability, requirements, and objectives. Driving forces in the history of aircraft include the quest for speed which involved design concepts incorporating jet propulsion systems and low drag features. The study of high speed design concepts promoted new experimental and analytical research techniques. These research techniques, in turn, have lead to concepts offering new performance potential. Design trends were directed toward increased speed, efficiency, productivity, and safety. Generally speaking, the research and development effort has been evolutionary in nature and, with the exception of the transition to supersonic flight, little has occurred since the origin of flight that has drastically changed the basic design fundamentals of aircraft. However, this does not preclude the possibility of dramatic changes in the future since the products of research are frequently unpredictable. Advances should be expected and sought in improved aerodynamics (reduced drag, enhanced lift, flow field exploitation); propulsion (improved engine cycles, multimode engines, alternate fuels, alternate power sources); structures (new materials, manufacturing techniques); all with a view toward increased efficiency and utility.

Spearman, M. L.

1983-01-01

58

The NASA research program on propulsion for supersonic cruise aircraft  

NASA Technical Reports Server (NTRS)

The objectives and status of the propulsion portion of a program aimed at advancing the technology and establishing a data base appropriate for the possible future development of supersonic cruise aircraft are reviewed. Research related to exhaust nozzles, combustors, and inlets that is covered by the noise, pollution, and dynamics programs is described.

Weber, R. J.

1975-01-01

59

Advanced materials research for long-haul aircraft turbine engines  

NASA Technical Reports Server (NTRS)

The status of research efforts to apply low to intermediate temperature composite materials and advanced high temperature materials to engine components is reviewed. Emerging materials technologies and their potential benefits to aircraft gas turbines were emphasized. The problems were identified, and the general state of the technology for near term use was assessed.

Signorelli, R. A.; Blankenship, C. P.

1978-01-01

60

ENIFAIR — EU research into engine integration on future transport aircraft  

Microsoft Academic Search

Following on from previous EU research programmes, ENIFAIR has extended the study of engine-airframe aerodynamic integration problems to the cases of Very High- and Ultra High-Bypass Ratio engine installations on representative modern aircraft. This article provides an overview of the work carried out and presents examples of the results achieved.

Wolfgang Burgsmüller; Heinz Hoheisel

2000-01-01

61

Flight research capabilities of the NASA/Army rotor systems research aircraft  

NASA Technical Reports Server (NTRS)

A description is given of the capabilities and limitations of the Rotor Systems Research Aircraft (RSRA) that was demonstrated during the development contract, and assesses the expected research capabilities of the RSRA on delivery to the government.

White, S., Jr.; Condon, G. W.

1978-01-01

62

Ocean Sciences: UNOLS Now Oversees Research Aircraft Facilities for Ocean Science  

Microsoft Academic Search

In recognition of the increasing importance and value of aircraft as observational platforms in oceanographic research, the University National Oceanographic Laboratory System (UNOLS) has established the Scientific Committee for Oceanographic Aircraft Research (SCOAR). SCOAR aims to establish procedures for research aircraft that follow the present UNOLS practices for research vessel use, with the goal of making it understandable, and easy,

John M. Bane; Robert Bluth; Charles Flagg; Haflidi Jonsson; W. Kendall Melville; Mike Prince; Daniel Riemer

2004-01-01

63

NASA research on structures and materials for supersonic cruise aircraft  

NASA Technical Reports Server (NTRS)

The technology and data base necessary for sound technical decisions regarding long haul supersonic cruise aircraft transportation systems are considered. The objectives and status of the research elements in the structures and materials program phase of the program are reviewed. Emphasis is placed on reductions in structural mass by research on advanced structural concepts, light-weight materials, improved loads, aeroelastic predictive techniques, and by development of efficient structural design procedures.

Cooper, P. A.; Heldenfels, R. R.

1976-01-01

64

The Proposed Use of Unmanned Aerial System Surrogate Research Aircraft for National Airspace System Integration Research  

NASA Technical Reports Server (NTRS)

Research is needed to determine what procedures, aircraft sensors and other systems will be required to allow Unmanned Aerial Systems (UAS) to safely operate with manned aircraft in the National Airspace System (NAS). This paper explores the use of Unmanned Aerial System (UAS) Surrogate research aircraft to serve as platforms for UAS systems research, development, and flight testing. These aircraft would be manned with safety pilots and researchers that would allow for flight operations almost anywhere in the NAS without the need for a Federal Aviation Administration (FAA) Certificate of Authorization (COA). With pilot override capability, these UAS Surrogate aircraft would be controlled from ground stations like true UAS s. It would be possible to file and fly these UAS Surrogate aircraft in the NAS with normal traffic and they would be better platforms for real world UAS research and development over existing vehicles flying in restricted ranges or other sterilized airspace. These UAS surrogate aircraft could be outfitted with research systems as required such as computers, state sensors, video recording, data acquisition, data link, telemetry, instrumentation, and Automatic Dependent Surveillance-Broadcast (ADS-B). These surrogate aircraft could also be linked to onboard or ground based simulation facilities to further extend UAS research capabilities. Potential areas for UAS Surrogate research include the development, flight test and evaluation of sensors to aide in the process of air traffic "see-and-avoid". These and other sensors could be evaluated in real-time and compared with onboard human evaluation pilots. This paper examines the feasibility of using UAS Surrogate research aircraft as test platforms for a variety of UAS related research.

Howell, Charles T., III

2011-01-01

65

Research in robust control for hypersonic aircraft  

NASA Technical Reports Server (NTRS)

The research during the second reporting period has focused on robust control design for hypersonic vehicles. An already existing design for the Hypersonic Winged-Cone Configuration has been enhanced. Uncertainty models for the effects of propulsion system perturbations due to angle of attack variations, structural vibrations, and uncertainty in control effectiveness were developed. Using H(sub infinity) and mu-synthesis techniques, various control designs were performed in order to investigate the impact of these effects on achievable robust performance.

Calise, A. J.

1993-01-01

66

An Indispensable Ingredient: Flight Research and Aircraft Design  

NASA Technical Reports Server (NTRS)

Flight research-the art of flying actual vehicles in the atmosphere in order to collect data about their behavior-has played a historic and decisive role in the design of aircraft. Naturally, wind tunnel experiments, computational fluid dynamics, and mathematical analyses all informed the judgments of the individuals who conceived of new aircraft. But flight research has offered moments of realization found in no other method. Engineer Dale Reed and research pilot Milt Thompson experienced one such epiphany on March 1, 1963, at the National Aeronautics and Space Administration s Dryden Flight Research Center in Edwards, California. On that date, Thompson sat in the cockpit of a small, simple, gumdrop-shaped aircraft known as the M2-F1, lashed by a long towline to a late-model Pontiac Catalina. As the Pontiac raced across Rogers Dry Lake, it eventually gained enough speed to make the M2-F1 airborne. Thompson braced himself for the world s first flight in a vehicle of its kind, called a lifting body because of its high lift-to-drag ratio. Reed later recounted what he saw:

Gorn, Michael H.

2003-01-01

67

Aircraft  

DOEpatents

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.

Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

1998-09-22

68

Aircraft  

DOEpatents

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.

Hibbs, Bart D. (1732 N. Grand Oaks, Altadena, CA 91001); Lissaman, Peter B. S. (3276 Rubio Canyon Rd., Altadena, CA 91001); Morgan, Walter R. (3217 Amarillo Ave., Simi Valley, CA 93063); Radkey, Robert L. (70 Eddystone Ct., Redwood City, CA 94065)

1998-01-01

69

Effects of asymmetry on the dynamic stability of aircraft  

NASA Technical Reports Server (NTRS)

The oblique wing concept for transonic aircraft was proposed to reduce drag. The dynamic stability of the aircraft was investigated by analytically determining the stability derivatives at angles of skew ranging from 0 and 45 deg and using these stability derivatives in a linear analysis of the coupled aircraft behavior. The stability derivatives were obtained using a lifting line aerodynamic theory and found to give reasonable agreement with derivatives developed in a previous study for the same aircraft. In the dynamic analysis, no instability or large changes occurred in the root locations for skew angles varying from 0 to 45 deg with the exception of roll convergence. The damping in roll, however, decreased by an order of magnitude. Rolling was a prominent feature of all the oscillatory mode shapes at high skew angles.

Fantino, R. E.; Parsons, E. K.; Powell, J. D.; Shevell, R. S.

1975-01-01

70

Overview of the Light Aircraft Aerosol Research Inlet (LAARI)  

NASA Astrophysics Data System (ADS)

Aircraft provide a mobile platform for measuring vertical profile aerosol properties. The efficacy of these measurements, however, is constrained by the aerosol inlet sampling efficiency. Larger particles are often lost to turbulent deposition and impaction inside the inlet and sampling lines, respectively. This precludes the measurement of coarse mode particles, important to visibility and radiative transfer studies. Turbulent deposition of large particles occurs when the sample air stream slows down within the inlet from the aircraft velocity to the recommended sampling velocities of the aerosol instruments (\\sim10 m s-1). Low-turbulence inlets that reduce turbulent deposition through the use of a porous diffuser cones are necessary for large aircraft with air speeds of 80 to 200 m s-1, but these are not feasible for light aircraft because of space and power requirements and may not even be necessary given the low air speeds of small aircraft. We have designed an aerosol inlet for a light aircraft platform with an average air speed of 60 m s-1 and a sample flow rate of 28.5 L min-1. The hemi-elliptical shaped, stainless steel inlet is 12.7 cm long. The front orifice has a 0.3175 cm diameter and the internal diameter expands to 0.9525 cm over a length of 9.2075 cm at an included angle of 4.3\\deg. The linear velocity of the sample stream as it exits the inlet is 6.7 m s-1. The calculated Reynolds number (Re) at the opening is 11,430 and decreases to 3,811 at the inlet terminus, with a pressure drop across the inlet opening of only 42 mb at an average flight temperature and pressure. Sampling line impaction is reduced by decreasing the number of bends upstream of the instruments. We have accomplished this by designing a parallel sampling manifold that splits the sample stream into four separate streams, three of which are split from the primary sample stream at an angle of 15\\deg. Theoretical investigations of sample flow and particle losses are underway with Computational Fluid Dynamics (CFD) software from FlowLab. Wind tunnel analyses using a Vibrating Orifice Aerosol Generator (VOAG) with optical particle counters upstream and downstream of the inlet and sampling lines will validate the theoretical calculations and provide empirical sampling efficiency values. This new inlet design will facilitate the more efficient collection of ambient particles, especially those in the coarse mode, from light aircraft. Because light aircraft are less expensive to operate than large aircraft and can make measurements in the lower atmosphere on a more routine basis, the Light Aircraft Aerosol Research Inlet (LAARI) will herald a new era of measurement capabilities in satellite validation work, column closure tests, and climate change studies.

Bueno, P. A.; Taubman, B. F.; Marufu, L. T.

2004-12-01

71

Lateral-Directional Stability and Control Characteristics of the Quiet Short-Haul Research Aircraft (QSRA).  

National Technical Information Service (NTIS)

The results are presented of flight experiments to determine the lateral-directional stability and control characteristics of the Quiet Short-Haul Research Aircraft (QSRA), an experimental aircraft designed to furnish information on various aerodynamic ch...

J. D. Stephenson J. A. Jeske G. H. Hardy

1990-01-01

72

Rotor systems research aircraft risk-reduction shake test  

NASA Technical Reports Server (NTRS)

A shake test and an extensive analysis of results were performed to evaluate the possibility of and the method for dynamically calibrating the Rotor Systems Research Aircraft (RSRA). The RSRA airframe was subjected to known vibratory loads in several degrees of freedom and the responses of many aircraft transducers were recorded. Analysis of the transducer responses using the technique of dynamic force determination showed that the RSRA, when used as a dynamic measurement system, could predict, a posteriori, an excitation force in a single axis to an accuracy of about 5 percent and sometimes better. As the analysis was broadened to include multiple degrees of freedom for the excitation force, the predictive ability of the measurement system degraded to about 20 percent, with the error occasionally reaching 100 percent. The poor performance of the measurement system is explained by the nonlinear response of the RSRA to vibratory forces and the inadequacy of the particular method used in accounting for this nonlinearity.

Wellman, J. Brent

1990-01-01

73

Advanced composites research and development for transport aircraft  

NASA Technical Reports Server (NTRS)

This paper highlights past experiences, lessons learned, state-of-the-art and current research activities directed at providing an integrated 'affordable' data base for composite structures. Composite secondary and empennage structures are in production on several transport aircraft. The weight reduction potential of composite structures is well documented. However, the cost to develop and produce composite structures remains the major barrier to increased application of this technology to transport aircraft. Specific technology items that are being developed under the NASA Advanced Composites Technology Program are described. Materials, design concepts, structural mechanics methodology and manufacturing processes and equipment are under development or are emerging that are expected to lead to an integrated 'affordable' data base. Technology verification for the next decade is expected to require fabrication and testing of full-scale wing-box and fuselage-section components before certificatiaon can occur and production commitments can be made.

Davis, John G., Jr.; Starnes, James H., Jr.; Johnston, Norman J.

1990-01-01

74

An Overview of NASA's SubsoniC Research Aircraft Testbed (SCRAT)  

NASA Technical Reports Server (NTRS)

National Aeronautics and Space Administration Dryden Flight Research Center acquired a Gulfstream III (GIII) aircraft to serve as a testbed for aeronautics flight research experiments. The aircraft is referred to as SCRAT, which stands for SubsoniC Research Aircraft Testbed. The aircraft’s mission is to perform aeronautics research; more specifically raising the Technology Readiness Level (TRL) of advanced technologies through flight demonstrations and gathering high-quality research data suitable for verifying the technologies, and validating design and analysis tools. The SCRAT has the ability to conduct a range of flight research experiments throughout a transport class aircraft’s flight envelope. Experiments ranging from flight-testing of a new aircraft system or sensor to those requiring structural and aerodynamic modifications to the aircraft can be accomplished. The aircraft has been modified to include an instrumentation system and sensors necessary to conduct flight research experiments along with a telemetry capability. An instrumentation power distribution system was installed to accommodate the instrumentation system and future experiments. An engineering simulation of the SCRAT has been developed to aid in integrating research experiments. A series of baseline aircraft characterization flights has been flown that gathered flight data to aid in developing and integrating future research experiments. This paper describes the SCRAT’s research systems and capabilities

Baumann, Ethan; Hernandez, Joe; Ruhf, John

2013-01-01

75

Predesign report for the rotor systems research aircraft  

NASA Technical Reports Server (NTRS)

A conceptual predesign of a compound helicopter for conducting rotor research is presented. The aircraft was selected by the Government as the better of two concepts submitted. The helicopter is a three place vehicle in the 24,000 pound gross weight class. It has been determined that the helicopter satisfies the requirements for the rotor research mission. The model has been predesigned sufficiently to allow an assessment of its performance and stability and control characteristics. A brief treatment of these subjects is included.

1972-01-01

76

V/STOL tilt rotor aircraft study. Volume 6: Preliminary design of a composite wing for tilt rotor research aircraft  

NASA Technical Reports Server (NTRS)

The results of a study of the use of composite materials in the wing of a tilt rotor aircraft are presented. An all-metal tilt rotor aircraft was first defined to provide a basis for comparing composite with metal structure. A configuration study was then done in which the wing of the metal aircraft was replaced with composite wings of varying chord and thickness ratio. The results of this study defined the design and performance benefits obtainable with composite materials. Based on these results the aircraft was resized with a composite wing to extend the weight savings to other parts of the aircraft. A wing design was then selected for detailed structural analysis. A development plan including costs and schedules to develop this wing and incorporate it into a proposed flight research tilt rotor vehicle has been devised.

Soule, V. A.; Badri-Nath, Y.

1973-01-01

77

Light transport and general aviation aircraft icing research requirements  

NASA Technical Reports Server (NTRS)

A short term and a long term icing research and technology program plan was drafted for NASA LeRC based on 33 separate research items. The specific items listed resulted from a comprehensive literature search, organized and assisted by a computer management file and an industry/Government agency survey. Assessment of the current facilities and icing technology was accomplished by presenting summaries of ice sensitive components and protection methods; and assessments of penalty evaluation, the experimental data base, ice accretion prediction methods, research facilities, new protection methods, ice protection requirements, and icing instrumentation. The intent of the research plan was to determine what icing research NASA LeRC must do or sponsor to ultimately provide for increased utilization and safety of light transport and general aviation aircraft.

Breeze, R. K.; Clark, G. M.

1981-01-01

78

Joined-wing research airplane feasibility study  

NASA Technical Reports Server (NTRS)

The joined wing is a new type of aircraft configuration which employs tandem wings arranged to form diamond shapes in plan view and front view. Wind-tunnel tests and finite-element structural analyses have shown that the joined wing provides the following advantages over a comparable wing-plus-tail system; lighter weight and higher stiffness, higher span-efficiency factor, higher trimmed maximum lift coefficient, lower wave drag, plus built-in direct lift and direct sideforce control capability. To verify these advantages at full scale a manned research airplane is required. A study has therefore been performed of the feasibility of constructing such an airplane, using the fuselage and engines of the existing NAA AD-1 oblique-wing airplane. Cost and schedule constraints favored converting the AD-1 rather than constructing a totally new airframe. By removing the outboard wing panels the configuration can simulate wings joined at 60, 80, or 100 percent of span. For maximum versatility the aircraft has alternative control surfaces (such as ailerons and elevators on the front and/or rear wings), and a removeable canard to explore canard/joined-wing interactions at high-lift conditions. Design, performance, and flying qualities are discussed.

Wolkovitch, J.

1984-01-01

79

Broadband electromagnetic sensors for aircraft lightning research. [electromagnetic effects of lightning on aircraft digital equipment  

NASA Technical Reports Server (NTRS)

A set of electromagnetic sensors, or electrically-small antennas, is described. The sensors are designed for installation on an F-106 research aircraft for the measurement of electric and magnetic fields and currents during a lightning strike. The electric and magnetic field sensors mount on the aircraft skin. The current sensor mounts between the nose boom and the fuselage. The sensors are all on the order of 10 cm in size and should produce up to about 100 V for the estimated lightning fields. The basic designs are the same as those developed for nuclear electromagnetic pulse studies. The most important electrical parameters of the sensors are the sensitivity, or equivalent area, and the bandwidth (or rise time). Calibration of sensors with simple geometries is reliably accomplished by a geometric analysis; all the sensors discussed possess geometries for which the sensitivities have been calculated. For the calibration of sensors with more complex geometries and for general testing of all sensors, two transmission lines were constructed to transmit known pulsed fields and currents over the sensors.

Trost, T. F.; Zaepfel, K. P.

1980-01-01

80

The high altitude aircraft program of NASA/Ames Research Center  

NASA Technical Reports Server (NTRS)

The ER-2 aircraft are used in NASA's Airborne Science and Applications Program as readily deployable high altitude sensor platforms to collect remote sensing and in situ data on Earth resources, celestial phenomena, atmospheric dynamics, and oceanic processes. Additionally, these aircraft are used for electronic sensor research and development and satellite investigative support. The scientific endeavors supported by these aircraft are listed.

Shelton, Gary; Coffland, Bruce

1991-01-01

81

Performance characteristics of a buoyant quad-rotor research aircraft  

NASA Technical Reports Server (NTRS)

Performance characteristics of a buoyant, quadrotor research aircraft, which represents a hybrid airship concept for heavy lift application, are described. Ceiling altitude and endurance for hovering at typical power levels, including partial power failure, are predicted. Climb performance at various altitude and gross weight conditions have been examined. Forward flight performance of this vehicle is illustrated in terms of typical performance parameters such as maximum speed, maximum range, and endurance, over the full range of its payload capability. Optimum payload weights have been identified which result in maximum range at sea level density altitude and constant endurance at various altitudes, both during hover and cruise flights.

Nagabhushan, B. L.; Jacobs, P. P.; Belknap, C. E.; Euler, D. A.

1982-01-01

82

The NASA Langley Research Center's Unmanned Aerial System Surrogate Research Aircraft  

NASA Technical Reports Server (NTRS)

Research is needed to determine what procedures, aircraft sensors and other systems will be required to allow Unmanned Aerial Systems (UAS) to safely operate with manned aircraft in the National Airspace System (NAS). The NASA Langley Research Center has transformed a Cirrus Design SR22 general aviation (GA) aircraft into a UAS Surrogate research aircraft to serve as a platform for UAS systems research, development, flight testing and evaluation. The aircraft is manned with a Safety Pilot and systems operator that allows for flight operations almost anywhere in the NAS without the need for a Federal Aviation Administration (FAA) Certificate of Authorization (COA). The UAS Surrogate can be controlled from a modular, transportable ground station like a true UAS. The UAS Surrogate is able to file and fly in the NAS with normal traffic and is a better platform for real world UAS research and development than existing vehicles flying in restricted ranges or other sterilized airspace. The Cirrus Design SR22 aircraft is a small, singleengine, four-place, composite-construction aircraft that NASA Langley acquired to support NASA flight-research programs like the Small Aircraft Transportation System (SATS) Project. Systems were installed to support flight test research and data gathering. These systems include: separate research power; multi-function flat-panel displays; research computers; research air data and inertial state sensors; video recording; data acquisition; data-link; S-band video and data telemetry; Common Airborne Instrumentation System (CAIS); Automatic Dependent Surveillance-Broadcast (ADS-B); instrumented surfaces and controls; and a systems operator work station. The transformation of the SR22 to a UAS Surrogate was accomplished in phases. The first phase was to modify the existing autopilot to accept external commands from a research computer that was connected by redundant data-link radios to a ground control station. An electro-mechanical auto-throttle was added in the next phase to provide ground station control of airspeed. Additional phases are in progress to add waypoint navigation and long range satellite voice and data communications. Potential areas for UAS Surrogate research include the development, flight test and evaluation of sensors to aid in the process of air traffic detect-sense-and-avoid. These sensors could be evaluated in real-time and compared with onboard human evaluation pilots. This paper describes the systems and design considerations that were incorporated in the development of the UAS Surrogate along with details of development problems encountered and the corresponding solutions.

Howell, Charles T., III; Jessup, Artie; Jones, Frank; Joyce, Claude; Sugden, Paul; Verstynen, Harry; Mielnik, John

2010-01-01

83

Research on hypersonic aircraft using pre-cooled turbojet engines  

Microsoft Academic Search

Systems analysis of a Mach 5 class hypersonic aircraft is performed. The aircraft can fly across the Pacific Ocean in two hours. A multidisciplinary optimization program for aerodynamics, structure, propulsion, and trajectory is used in the analysis. The result of each element model is improved using higher accuracy analysis tools. The aerodynamic performance of the hypersonic aircraft is examined through

Hideyuki Taguchi; Hiroaki Kobayashi; Takayuki Kojima; Atsushi Ueno; Shunsuke Imamura; Motoyuki Hongoh

84

Fabrication research for supersonic cruise aircraft. [YF-12 skin structures  

NASA Technical Reports Server (NTRS)

Advanced fabrication and joining processes for titanium and composite materials are being investigated by NASA to develop technology for the Supersonic Cruise Research (SCR) Program. Full-scale structural panels are being designed and fabricated to meet the criteria of an existing integrally stiffened shear panel on the upper wing surface of the NASA YF-12 aircraft. The program consists of laboratory testing and Mach 3 flight service of full-scale structural panels and laboratory testing of representative structural element specimens. Borsic/aluminum honeycomb-core, titanium clad Borsic/aluminum skin-stringer, graphite/PMR-15 polyimide honeycomb-core, and titanium superplastically formed/diffusion bonded panels have been designed, fabricated, and tested. Graphite/LARC-160 polyimide skin-stringer panels have been designed, and fabrication methods are being developed.

Hoffman, E. L.; Bales, T. T.; Payne, L.

1979-01-01

85

Status of research into lightning effects on aircraft  

NASA Technical Reports Server (NTRS)

Developments in aircraft lightning protection since 1938 are reviewed. Potential lightning problems resulting from present trends toward the use of electronic controls and composite structures are discussed, along with presently available lightning test procedures for problem assessment. The validity of some procedures is being questioned because of pessimistic results and design implications. An in-flight measurement program is needed to provide statistics on lightning severity at flight altitudes and to enable more realistic tests, and operators are urged to supply researchers with more details on electronic components damaged by lightning strikes. A need for review of certain aspects of fuel system vulnerability is indicated by several recent accidents, and specific areas for examination are identified. New educational materials and standardization activities are also noted.

Plumer, J. A.

1976-01-01

86

Current and Future Research in Active Control of Lightweight, Flexible Structures Using the X-56 Aircraft  

NASA Technical Reports Server (NTRS)

The X-56 Multi-Utility Technology Testbed aircraft system is a versatile experimental research flight platform. The system was primarily designed to investigate active control of lightweight flexible structures, but is reconfigurable and capable of hosting a wide breadth of research. Current research includes flight experimentation of a Lockheed Martin designed active control flutter suppression system. Future research plans continue experimentation with alternative control systems, explore the use of novel sensor systems, and experiments with the use of novel control effectors. This paper describes the aircraft system, current research efforts designed around the system, and future planned research efforts that will be hosted on the aircraft system.

Ryan, John J.; Bosworth, John T.; Burken, John J.; Suh, Peter M.

2014-01-01

87

Research on fault pattern recognition for aircraft fuel system with its performance simulation  

Microsoft Academic Search

This paper presents application research on fault pattern recognition for aircraft fuel system based on its performance simulation. Fault pattern recognition method is used to perform fault detection, fault isolation, fault prognostics and so on in complicated system, which is basic research contents of prognostics and health management (PHM). Since the hardware of fuel system for an aircraft is too

Haifeng Wang; Bifeng Song; Fangyi Wan

2011-01-01

88

Forced Oscillation Wind Tunnel Testing for FASER Flight Research Aircraft  

NASA Technical Reports Server (NTRS)

As unmanned air vehicles (UAVs) continue to expand their flight envelopes into areas of high angular rate and high angle of attack, modeling the complex unsteady aerodynamics for simulation in these regimes has become more difficult using traditional methods. The goal of this experiment was to improve the current six degree-of-freedom aerodynamic model of a small UAV by replacing the analytically derived damping derivatives with experimentally derived values. The UAV is named the Free-flying Aircraft for Sub-scale Experimental Research, FASER, and was tested in the NASA Langley Research Center 12- Foot Low-Speed Tunnel. The forced oscillation wind tunnel test technique was used to measure damping in the roll and yaw axes. By imparting a variety of sinusoidal motions, the effects of non-dimensional angular rate and reduced frequency were examined over a large range of angle of attack and side-slip combinations. Tests were performed at angles of attack from -5 to 40 degrees, sideslip angles of -30 to 30 degrees, oscillation amplitudes from 5 to 30 degrees, and reduced frequencies from 0.010 to 0.133. Additionally, the effect of aileron or elevator deflection on the damping coefficients was examined. Comparisons are made of two different data reduction methods used to obtain the damping derivatives. The results show that the damping derivatives are mainly a function of angle of attack and have dependence on the non-dimensional rate and reduced frequency only in the stall/post-stall regime

Hoe, Garrison; Owens, Donald B.; Denham, Casey

2012-01-01

89

An overview of the quiet short-haul research aircraft program  

NASA Technical Reports Server (NTRS)

An overview of the Quiet Short Haul Research Aircraft (QSRA) Program is presented, with special emphasis on its propulsion and acoustic aspects. A description of the NASA technical participation in the program including wind tunnel testing, engine ground tests, and advanced aircraft simulation is given. The aircraft and its systems are described and, measured performance, where available, is compared to program goals. Preliminary data indicate that additional research and development are needed in some areas of which acoustics is an example. Some of these additional research areas and potential experiments using the QSRA to develop the technology are discussed. The concept of the QSRA as a national flight research facility is explained.

Shovlin, M. D.; Cochrane, J. A.

1978-01-01

90

Engineering and Technical Configuration Aspects of HIAPER, the new NSF/NCAR Research Aircraft  

NASA Astrophysics Data System (ADS)

The High-performance Instrumented Airborne Platform for Environmental Research, or HIAPER, is the new research aircraft presently being developed at the National Center for Atmospheric Research (NCAR) to serve the environmental research needs of the National Science Foundation (NSF) for the next several decades. The basic aircraft -- a Gulfstream V (G-V) business jet -- has been completed and will shortly undergo extensive modification to prepare it for future deployments in support of a variety of geosciences research missions. This presentation will focus on the many design and engineering considerations that have been made and are yet to come in converting a "green" business jet into a versatile research aircraft to serve the environmental research community. The project teams composed of engineers and scientists from NCAR and the scientific community at large are faced with trade offs involving costs of modifications, airframe structural integrity, aircraft performance (e.g. weight, drag), cabin environment, locations of inlet and sampling ports and FAA certification requirements. Many of the specific engineering specifications and modifications that have been made to date will be presented by way of engineering drawings, graphical depictions and actual photographs of the aircraft structure. Additionally, projected performance data of the modified-for-research aircraft will be presented along with some of the analyses performed to arrive at critical decisions (e.g. CFD airflow analysis). Finally, some of the details of the aircraft "infrastructure" such as signal and power wiring, generic cabin layout and data acquisition will be discussed.

Friesen, R.; Laursen, K.

2002-12-01

91

The F-18 high alpha research vehicle: A high-angle-of-attack testbed aircraft  

NASA Technical Reports Server (NTRS)

The F-18 High Alpha Research Vehicle is the first thrust-vectoring testbed aircraft used to study the aerodynamics and maneuvering available in the poststall flight regime and to provide the data for validating ground prediction techniques. The aircraft includes a flexible research flight control system and full research instrumentation. The capability to control the vehicle at angles of attack up to 70 degrees is also included. This aircraft was modified by adding a pitch and yaw thrust-vectoring system. No significant problems occurred during the envelope expansion phase of the program. This aircraft has demonstrated excellent control in the wing rock region and increased rolling performance at high angles of attack. Initial pilot reports indicate that the increased capability is desirable although some difficulty in judging the size and timing of control inputs was observed. The aircraft, preflight ground testing and envelope expansion flight tests are described.

Regenie, Victoria; Gatlin, Donald; Kempel, Robert; Matheny, Neil

1992-01-01

92

Tiltrotor Research Aircraft composite blade repairs - Lessons learned  

NASA Technical Reports Server (NTRS)

The XV-15, N703NA Tiltrotor Research Aircraft located at the NASA Ames Research Center, Moffett Field, California, currently uses a set of composite rotor blades of complex shape known as the advanced technology blades (ATBs). The main structural element of the blades is a D-spar constructed of unidirectional, angled fiberglass/graphite, with the aft fairing portion of the blades constructed of a fiberglass cross-ply skin bonded to a Nomex honeycomb core. The blade tip is a removable laminate shell that fits over the outboard section of the spar structure, which contains a cavity to retain balance weights. Two types of tip shells are used for research. One is highly twisted (more than a conventional helicopter blade) and has a hollow core constructed of a thin Nomex-honeycomb-and-fiberglass-skin sandwich; the other is untwisted with a solid Nomex honeycomb core and a fiberglass cross-ply skin. During initial flight testing of the blades, a number of problems in the composite structure were encountered. These problems included debonding between the fiberglass skin and the honeycomb core, failure of the honeycomb core, failures in fiberglass splices, cracks in fiberglass blocks, misalignment of mated composite parts, and failures of retention of metal fasteners. Substantial time was spent in identifying and repairing these problems. Discussed here are the types of problems encountered, the inspection procedures used to identify each problem, the repairs performed on the damaged or flawed areas, the level of criticality of the problems, and the monitoring of repaired areas. It is hoped that this discussion will help designers, analysts, and experimenters in the future as the use of composites becomes more prevalent.

Espinosa, Paul S.; Groepler, David R.

1992-01-01

93

Tiltrotor research aircraft composite blade repairs: Lessons learned  

NASA Technical Reports Server (NTRS)

The XV-15, N703NA Tiltrotor Research Aircraft located at the NASA Ames Research Center, Moffett Field, California, currently uses a set of composite rotor blades of complex shape known as the advanced technology blades (ATBs). The main structural element of the blades is a D-spar constructed of unidirectional, angled fiberglass/graphite, with the aft fairing portion of the blades constructed of a fiberglass cross-ply skin bonded to a Nomex honeycomb core. The blade tip is a removable laminate shell that fits over the outboard section of the spar structure, which contains a cavity to retain balance weights. Two types of tip shells are used for research. One is highly twisted (more than a conventional helicopter blade) and has a hollow core constructed of a thin Nomex-honeycomb-and-fiberglass-skin sandwich; the other is untwisted with a solid Nomex honeycomb core and a fiberglass cross-ply skin. During initial flight testing of the blades, a number of problems in the composite structure were encountered. These problems included debonding between the fiberglass skin and the honeycomb core, failure of the honeycomb core, failures in fiberglass splices, cracks in fiberglass blocks, misalignment of mated composite parts, and failures of retention of metal fasteners. Substantial time was spent in identifying and repairing these problems. Discussed here are the types of problems encountered, the inspection procedures used to identify each problem, the repairs performed on the damaged or flawed areas, the level of criticality of the problems, and the monitoring of repaired areas. It is hoped that this discussion will help designers, analysts, and experimenters in the future as the use of composites becomes more prevalent.

Espinosa, Paul S.; Groepler, David R.

1991-01-01

94

Research on Simulation Method of Flight Safety for Civil Aircraft  

Microsoft Academic Search

\\u000a Flight safety evaluation technique will significantly guide the new-style aircraft preliminary design. Based on the principle\\u000a of Human-machine System Engineering, the dynamic characteristic and modeling method of both pilot and aircraft are investigated.\\u000a Pilot decision-making and Aircraft Failure model are proposed, and then a low-cost, convenient software evaluation system\\u000a for flight safety simulation is developed based on the object-oriented technique.

Wei Zhang; Hehe Yi; Zhi Ma

95

Global stratospheric change: Requirements for a Very-High-Altitude Aircraft for Atmospheric Research  

NASA Technical Reports Server (NTRS)

The workshop on Requirements for a Very-High-Altitude Aircraft for Atmospheric Research, sponsored by NASA Ames Research Center, was held July 15 to 16, 1989, at Truckee, CA. The workshop had two purposes: to assess the scientific justification for a new aircraft that will support stratospheric research beyond the altitudes accessible to the NASA ER-2; and to determine the aircraft characteristics (e.g., ceiling altitude, payload accommodations, range, flight duration, operational capabilities) required to perform the stratospheric research referred to in the justification. To accomplish these purposes, the workshop brought together a cross-section of stratospheric scientists with several aircraft design and operations experts. The stratospheric scientists included theoreticians as well as experimenters with experience in remote and in situ measurements from satellites, rockets, balloons, aircraft, and the ground. Discussions of required aircraft characteristics focused on the needs of stratospheric research. It was recognized that an aircraft optimal for stratospheric science would also be useful for other applications, including remote measurements of Earth's surface. A brief description of these other applications was given at the workshop.

1989-01-01

96

Rotor systems research aircraft predesign study. Volume 2: Conceptual study report  

NASA Technical Reports Server (NTRS)

The overall feasibility of the technical requirements and concepts for a rotor system research aircraft (RSRA) was determined. The designs of two aircraft were then compared against the RSRA requirements. One of these is an all new aircraft specifically designed as an RSRA vehicle. A new main rotor, transmission, wings, and fuselage are included in this design. The second aircraft uses an existing Sikorsky S-61 main rotor, an S-61 roller gearbox, and a highly modified Sikorsky S-67 airframe. The wing for this aircraft is a new design. Both aircraft employ a fan-in-fin anti-torque/yaw control system, T58-GE-16 engines for rotor power, and TF34-GE-2 turbofans for auxiliary thrust. Each aircraft meets the basic requirements and goals of the program. The all new aircraft has inflight variable main rotor shaft tilt, a side-by-side cockpit seating arrangement, and is slightly faster in the compound mode. It is also somewhat lighter since it uses new dynamic components specifically designed for the RSRA. Preliminary development plans, including schedules and costs, were prepared for both of these aircraft.

Schmidt, S. A.; Linden, A. W.

1972-01-01

97

The Small Aircraft Transportation System (SATS): Research Collaborations with the NASA Langley Research Center  

NASA Technical Reports Server (NTRS)

The aviation industry is an integral part of the world s economy. Travelers have consistently chosen aviation as their mode of transportation as it is reliable, time efficient and safe. The out- dated Hub and Spoke system, coupled with high demand, has led to delays, cancellations and gridlock. NASA is developing innovative solutions to these and other air transportation problems. This research is being conducted through partnerships with federal agencies, industry stakeholders, and academia, specifically the University of Nebraska at Omaha. Each collaborator is pursuing the NASA General Aviation Roadmap through their involvement in the expansion of the Small Aircraft Transportation System (SATS). SATS will utilize technologically advanced small aircraft to transport travelers to and from rural and isolated communities. Additionally, this system will provide a safe alternative to the hub and spoke system, giving more time to more people through high-speed mobility and increased accessibility.

Tarry, Scott E.; Bowen, Brent D.; Nickerson, Jocelyn S.

2002-01-01

98

STRATEGIC RESEARCH AGENDA FOR HIGH-ALTITUDE AIRCRAFT AND AIRSHIP REMOTE SENSING APPLICATIONS  

Microsoft Academic Search

This contribution addresses the remote sensing chapter of the USE HAAS Study, a Specific Support Action of the European Union Sixth Framework Program, aiming at producing a Strategic Research Agenda for High Altitude Aircraft and Airships.

C. Barbier; B. Delauréb; A. Laviec

99

Quiet Short-Haul Research Aircraft Joint Navy/NASA Sea Trials  

NASA Technical Reports Server (NTRS)

The Quiet Short-Haul Research Aircraft (QSRA) is a flight facility which Ames Research Center is using to conduct a broad program of terminal area and low-speed, propulsive-life flight research. A joint Navy/NASA flight research program used the QSRA to investigate the application of advanced propulsive-lift technology to the naval aircraft-carrier environment. Flight performance of the QSRA is presented together with the results or the joint Navy/NASA flight program. During the joint program, the QSRA operated aboard the USS Kitty Hawk for 4 days, during which numerous unarrested landings and free deck takeoffs were accomplished. These operations demonstrated that a large aircraft incorporating upper-surface-blowing, propulsive-life technology can be operated in the aircraft-carrier environment without any unusual problems.

Queen, S.; Cochrane, J.

1982-01-01

100

Research and Feasibility of an Integrated Servo Pump Actuator Package for Aircraft Flight Control.  

National Technical Information Service (NTIS)

A research and development study was conducted to determine the feasibility of utilizing the servo pump principle in the design of Integrated Servo Actuator Packages that are planned for use in military aircraft primary flight control systems. A feasibili...

K. F. Becker N. F. Pedersen

1971-01-01

101

NASA/Army XV-15 tilt rotor research aircraft familiarization document  

NASA Technical Reports Server (NTRS)

The design features and general characteristics of the NASA/Army XV-15 tilt rotor research aircraft are described. This aircraft was conceived as a proof-of-concept vehicle and a V/STOL research tool for integrated wind tunnel, flight-simulation, and flight-test investigations. Discussions of special design provisions and safety considerations necessary to perform these missions are included in this report. In addition to predictions of aircraft and engine performance for the hover, helicopter, and airplane flight modes, analytical estimates of the structural and dynamic limitations of the XV-15 are provided.

1975-01-01

102

NASA-Langley Research Center's Aircraft Condition Analysis and Management System Implementation  

NASA Technical Reports Server (NTRS)

This document describes the hardware implementation design and architecture of Aeronautical Radio Incorporated (ARINC)'s Aircraft Condition Analysis and Management System (ACAMS), which was developed at NASA-Langley Research Center (LaRC) for use in its Airborne Research Integrated Experiments System (ARIES) Laboratory. This activity is part of NASA's Aviation Safety Program (AvSP), the Single Aircraft Accident Prevention (SAAP) project to develop safety-enabling technologies for aircraft and airborne systems. The fundamental intent of these technologies is to allow timely intervention or remediation to improve unsafe conditions before they become life threatening.

Frye, Mark W.; Bailey, Roger M.; Jessup, Artie D.

2004-01-01

103

Aeroacoustic research in the Netherlands related to aircraft development  

NASA Astrophysics Data System (ADS)

For jet noise reduction the feasibility of a lined ejector nozzle for the Fokker F28 aircraft was investigated by scale model measurements using decomposed hydrogen peroxide for hot jet simulation. Thrust performance measurements were included. For the design of optimum acoustic liners a mathematical model was developed to represent the fan and engine duct acoustically, taking into account the sound generation by rotor wake/stator interaction. Acoustic measurements were performed in the engine inlet of a Fokker F28 aircraft during flight. Techniques and facilities were developed for accurate in-situ measurements of the impedance of acoustic liner materials under realistic conditions. The technique was also demonstrated in-flight. Large reductions of the propeller noise level inside the cabin of the Fokker F27 aircraft were obtained by dynamic vibration absorbers on the fuselage wall structure.

Dewolf, W. B.; Sarin, S. L.

1985-05-01

104

An overview of the current NASA program on aircraft icing research  

NASA Technical Reports Server (NTRS)

The NASA Lewis Research Center is presently conducting an aircraft icing research program, the major thrust of which is to advance technologies that improve our ability to model the icing phenomenon and its effect on aircraft. The approach employs three interrelated elements: analysis; wind tunnel experiments; and, considerable flight testing in natural icing clouds. This paper presents a brief overview of this program with emphasis on recent accomplishments.

Ranaudo, Richard J.; Reehorst, Andrew L.; Potapczuk, Mark G.

1988-01-01

105

A flight investigation of the STOL characteristics of an augmented jet flap STOL research aircraft  

NASA Technical Reports Server (NTRS)

The flight test program objectives are: (1) To determine the in-flight aerodynamic, performance, and handling qualities of a jet STOL aircraft incorporating the augmented jet flap concept; (2) to compare the results obtained in flight with characteristics predicted from wind tunnel and simulator test results; (3) to contribute to the development of criteria for design and operation of jet STOL transport aircraft; and (4) to provide a jet STOL transport aircraft for STOL systems research and development. Results obtained during the first 8 months of proof-of-concept flight testing of the aircraft in STOL configurations are reported. Included are a brief description of the aircraft, fan-jet engines, and systems; a discussion of the aerodynamic, stability and control, and STOL performance; and pilot opinion of the handling qualities and operational characteristics.

Quigley, H. C.; Innis, R. C.; Grossmith, S.

1974-01-01

106

Shipboard trials of the Quiet Short-Haul Research Aircraft /QSRA/  

NASA Technical Reports Server (NTRS)

The feasibility of the application of advanced state-of-the-art high lift STOL aircraft in the aircraft carrier environment was evaluated using the NASA Quiet Short-Haul Research Aircraft (QSRA). The QSRA made repeated unarrested landings and free deck takeoffs from the USS Kitty Hawk while being flown by three pilots of significant different backgrounds. The exercise demonstrated that the USB propulsive lift technology presents no unusual problems in the aircraft carrier environment. Optimum parameters for landing the QSRA were determined from the shore-based program; these proved satisfactory during operations aboard ship. Correlation of shipboard experience with shore-based data indicates that both free deck takeoffs and unarrested landings could be conducted with zero to 35 knots of wind across the deck of an aircraft carrier the size of the USS Kitty Hawk.

Martin, J. L.; Strickland, P. B.

1980-01-01

107

Status of the NASA YF-12 Propulsion Research Program. [engine design of aircraft engines for supersonic aircraft  

NASA Technical Reports Server (NTRS)

The YF-12 research program was initiated to establish a technology base for the design of an efficient propulsion system for supersonic cruise aircraft. The major technology areas under investigation in this program are inlet design analysis, propulsion system steady-state performance, propulsion system dynamic performance, inlet and engine control systems, and airframe/propulsion system interactions. The objectives, technical approach, and status of the YF-12 propulsion program are discussed. Also discussed are the results obtained to date by the NASA Ames, Lewis, and Dryden research centers. The expected technical results and proposed future programs are also given. Propulsion system configurations are shown.

Albers, J. A.

1976-01-01

108

Research on Visual Display Integration for Advanced Fighter Aircraft.  

National Technical Information Service (NTIS)

This 'Visual Display Integration' study was conducted to determine the display integration options projected available for inclusion in an attack/fighter aircraft crew station design in the 1985-1990 time. A second objective was the definition of an evalu...

G. S. Mills M. A. Grayson S. L. Loy R. A. Jauer

1978-01-01

109

The NASA Earth Research-2 (ER-2) Aircraft: A Flying Laboratory for Earth Science Studies  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration Dryden Flight Research Center, Edwards, California, has two Lockheed Martin Corporation (Bethesda, Maryland) Earth Research-2 (ER2) aircraft that serve as high-altitude and long-range flying laboratories. The ER-2 aircraft has been successfully utilized to conduct scientific studies of stratospheric and tropospheric chemistry, land-use mapping, disaster assessment, preliminary testing and calibration and validation of satellite sensors. The research missions for the ER-2 aircraft are planned, implemented, and managed by the Dryden Flight Research Center Science Mission Directorate. Maintenance and instrument payload integration is conducted by Dryden personnel. The ER-2 aircraft provides experimenters with a wide array of payload accommodations areas with suitable environment control with required electrical and mechanical interfaces. Missions may be flown out of Dryden or from remote bases worldwide, according to research requirements. The NASA ER-2 aircraft is utilized by a variety of customers, including U.S. Government agencies, civilian organizations, universities, and state governments. The combination of the ER-2 aircraft s range, endurance, altitude, payload power, payload volume and payload weight capabilities complemented by a trained maintenance and operations team provides an excellent and unique platform system to the science community and other customers.

Navarro, Robert

2007-01-01

110

Research on hypersonic aircraft using pre-cooled turbojet engines  

NASA Astrophysics Data System (ADS)

Systems analysis of a Mach 5 class hypersonic aircraft is performed. The aircraft can fly across the Pacific Ocean in 2 h. A multidisciplinary optimization program for aerodynamics, structure, propulsion, and trajectory is used in the analysis. The result of each element model is improved using higher accuracy analysis tools. The aerodynamic performance of the hypersonic aircraft is examined through hypersonic wind tunnel tests. A thermal management system based on the data of the wind tunnel tests is proposed. A pre-cooled turbojet engine is adopted as the propulsion system for the hypersonic aircraft. The engine can be operated continuously from take-off to Mach 5. This engine uses a pre-cooling cycle using cryogenic liquid hydrogen. The high temperature inlet air of hypersonic flight would be cooled by the same liquid hydrogen used as fuel. The engine is tested under sea level static conditions. The engine is installed on a flight test vehicle. Both liquid hydrogen fuel and gaseous hydrogen fuel are supplied to the engine from a tank and cylinders installed within the vehicle. The designed operation of major components of the engine is confirmed. A large amount of liquid hydrogen is supplied to the pre-cooler in order to make its performance sufficient for Mach 5 flight. Thus, fuel rich combustion is adopted at the afterburner. The experiments are carried out under the conditions that the engine is mounted upon an experimental airframe with both set up either horizontally or vertically. As a result, the operating procedure of the pre-cooled turbojet engine is demonstrated.

Taguchi, Hideyuki; Kobayashi, Hiroaki; Kojima, Takayuki; Ueno, Atsushi; Imamura, Shunsuke; Hongoh, Motoyuki; Harada, Kenya

2012-04-01

111

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

NASA Technical Reports Server (NTRS)

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 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 provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.

1996-01-01

112

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

NASA Technical Reports Server (NTRS)

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-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 provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.

1996-01-01

113

An Evaluation Technique for an F\\/A-18 Aircraft Loads Model Using F\\/A-18 Systems Research Aircraft Flight Data  

Microsoft Academic Search

A limited evaluation of the F\\/A-18 baselineloads model was performed on the SystemsResearch Aircraft at NASA Dryden FlightResearch Center (Edwards, California).Boeing developed the F\\/A-18 loads modelusing a linear aeroelastic analysis inconjunction with a flight simulator todetermine loads at discrete locations on theaircraft. This experiment was designed sothat analysis of doublets could be used toestablish aircraft aerodynamic and loadsresponse at 20

Candida D. Olney; Heather Hillebrandt; Eric Y. Reichenbach

2000-01-01

114

Rotor systems research aircraft of predesign study. Volume 1: Summary and conclusions  

NASA Technical Reports Server (NTRS)

The results are summarized of a study to develop a versatile research aircraft for flight testing a wide variety of advanced helicopter and compound rotor systems. The aircraft is required to accept these rotors with minimal changes in the basic vehicle. Rotors envisioned for testing include conventional rotors plus variable geometry, variable twist, variable diameter, coaxial, jet flap, circulation control, and slowed rotors. Various disc loadings would be accommodated. The aircraft must be configured to measure performance more accurately than past test vehicles. In addition, the aircraft would have a wing to off load the rotor while measuring performance during lightly loaded conditions. It would have variable drag and propulsive force so that the rotor can be tested while producing different values of horizontal force.

Linden, A. W.

1972-01-01

115

Development of a Low-Cost Sub-Scale Aircraft for Flight Research: The FASER Project  

NASA Technical Reports Server (NTRS)

An inexpensive unmanned sub-scale aircraft was developed to conduct frequent flight test experiments for research and demonstration of advanced dynamic modeling and control design concepts. This paper describes the aircraft, flight systems, flight operations, and data compatibility including details of some practical problems encountered and the solutions found. The aircraft, named Free-flying Aircraft for Sub-scale Experimental Research, or FASER, was outfitted with high-quality instrumentation to measure aircraft inputs and states, as well as vehicle health parameters. Flight data are stored onboard, but can also be telemetered to a ground station in real time for analysis. Commercial-off-the-shelf hardware and software were used as often as possible. The flight computer is based on the PC104 platform, and runs xPC-Target software. Extensive wind tunnel testing was conducted with the same aircraft used for flight testing, and a six degree-of-freedom simulation with nonlinear aerodynamics was developed to support flight tests. Flight tests to date have been conducted to mature the flight operations, validate the instrumentation, and check the flight data for kinematic consistency. Data compatibility analysis showed that the flight data are accurate and consistent after corrections are made for estimated systematic instrumentation errors.

Owens, Donald B.; Cox, David E.; Morelli, Eugene A.

2006-01-01

116

COMPATIBILITY OF AIRCRAFT AND SHIPBORNE INSTRUMENTS USED IN AIR-SEA INTERACTION RESEARCH  

Microsoft Academic Search

On June 16, 1966, an experiment was performed off the east coast of Florida that involved two research aircraft, one from the Naval Oceanographic Office and one from ESSA's Research Flight Facility, and the USCGSS Peirce, aboard which were two scientists from ESSA's Sea Air Interaction Laboratory, and the Weather Bureau Airport Station at Jacksonville, Fla. The purpose of this

JAMES D. McFADDEN; JOHN W. WILKERSON

1967-01-01

117

Impact dynamics research facility for full-scale aircraft crash testing  

NASA Technical Reports Server (NTRS)

An impact dynamics research facility (IDRF) was developed to crash test full-scale general aviation aircraft under free-flight test conditions. The aircraft are crashed into the impact surface as free bodies; a pendulum swing method is used to obtain desired flight paths and velocities. Flight paths up to -60 deg and aircraft velocities along the flight paths up to about 27.0 m/s can be obtained with a combination of swing-cable lengths and release heights made available by a large gantry. Seven twin engine, 2721-kg aircraft were successfully crash tested at the facility, and all systems functioned properly. Acquisition of data from signals generated by accelerometers on board the aircraft and from external and onboard camera coverage was successful in spite of the amount of damage which occurred during each crash. Test parameters at the IDRF are controllable with flight path angles accurate within 8 percent, aircraft velocity accurate within 6 percent, pitch angles accurate to 4.25 deg, and roll and yaw angles acceptable under wind velocities up to 4.5 m/s.

Vaughan, V. L. J.; Alfaro-Bou, E.

1976-01-01

118

Simulation test results for lift/cruise fan research and technology aircraft  

NASA Technical Reports Server (NTRS)

A flight simulation program was conducted on the flight simulator for advanced aircraft (FSAA). The flight simulation was a part of a contracted effort to provide a lift/cruise fan V/STOL aircraft mathematical model for flight simulation. The simulated aircraft is a configuration of the Lift/Cruise Fan V/STOL research technology aircraft (RTA). The aircraft was powered by three gas generators driving three fans. One lift fan was installed in the nose of the aircraft, and two lift/cruise fans at the wing root. The thrust of these fans was modulated to provide pitch and roll control, and vectored to provide yaw, side force control, and longitudinal translation. Two versions of the RTA were defined. One was powered by the GE J97/LF460 propulsion system which was gas-coupled for power transfer between fans for control. The other version was powered by DDA XT701 gas generators driving 62 inch variable pitch fans. The flight control system in both versions of the RTA was the same.

Bland, M. P.; Konsewicz, R. K.

1976-01-01

119

QSRA Joint Navy/NASA sea trials. [Quiet Short Haul Research Aircraft  

NASA Technical Reports Server (NTRS)

The Quiet Short-Haul Research Aircraft (QSRA), used to conduct a broad program of terminal area and low speed propulsive-lift flight research, is discussed. Flight performance of the QSRA is presented together with the results of the joint Navy/NASA flight program. It is found that both free-deck takeoffs and unarrested landings can be conducted with winds across the deck of zero to 35 knots on an aircraft carrier the size of the USS Kitty Hawk with all engines operating. QSRA characteristics and aerodynamic data are included.

Queen, S.; Cochrane, J.

1981-01-01

120

Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements  

NASA Astrophysics Data System (ADS)

A method is described that estimates the error in the static pressure measurement on an aircraft from differential pressure measurements on the hemispherical surface of a Rosemount model 858AJ air velocity probe mounted on a boom ahead of the aircraft. The theoretical predictions for how the pressure should vary over the surface of the hemisphere, involving an unknown sensitivity parameter, leads to a set of equations that can be solved for the unknowns - angle of attack, angle of sideslip, dynamic pressure and the error in static pressure - if the sensitivity factor can be determined. The sensitivity factor was determined on the University of Wyoming King Air research aircraft by comparisons with the error measured with a carefully designed sonde towed on connecting tubing behind the aircraft - a trailing cone - and the result was shown to have a precision of about ±10 Pa over a wide range of conditions, including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, geometric altitude data from a combined Global Navigation Satellite System (GNSS) and inertial measurement unit (IMU) system are used to estimate acceleration effects on the error, and the algorithm is shown to predict corrections to a precision of better than ±20 Pa under those conditions. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are discussed.

Rodi, A. R.; Leon, D. C.

2012-11-01

121

Low-speed airspeed calibration data for a single-engine research-support aircraft  

NASA Technical Reports Server (NTRS)

A standard service airspeed system on a single engine research support airplane was calibrated by the trailing anemometer method. The effects of flaps, power, sideslip, and lag were evaluated. The factory supplied airspeed calibrations were not sufficiently accurate for high accuracy flight research applications. The trailing anemometer airspeed calibration was conducted to provide the capability to use the research support airplane to perform pace aircraft airspeed calibrations.

Holmes, B. J.

1980-01-01

122

Subminiaturization for ERAST instrumentation (Environmental Research Aircraft and Sensor Technology)  

NASA Technical Reports Server (NTRS)

We are focusing on the Argus as an example to demonstrate our philosophy on miniaturization of airborne analytical instruments for the study of atmospheric chemistry. Argus is a two channel, tunable-diode laser absorption spectrometer developed at NASA for the measurement of nitrogen dioxide (N2O) (4.5 micrometers) and ammonia (CH3) (3.3 micrometers) at the 0.1 parts per billion (ppb) level from the Perseus aircraft platform at altitudes up to 30 km. Although Argus' mass is down to 23 kg from the 197 kg Atlas, its predecessor, our goal is to design a next-generation subminiaturized instrument weighing less than 1 kg, measuring a few cm(exp 3) and able to eliminate dewars for cooling. Current designs enable use to make a small,inexpensive, monolithic spectrometer without the required sensitivity range. Further work is on its way to increase sensitivity. We are continuing to zero-base the technical approach in terms of the specifications for the given instrument. We are establishing a check list of questions to hone into the best micromachining approach and to superpose on the answers insights in scaling laws and flexible engineering designs to enable more relaxed tolerances for the smallest of the components.

Madou, Marc; Lowenstein, Max; Wegener, Steven

1995-01-01

123

Flight Measured Downwash of the QSRA (Quiet Short-Haul Research Aircraft).  

National Technical Information Service (NTIS)

Several reports have been written on the performance of the Quiet Short-Haul Research Aircraft, which shows the advantages of upper-surface blowing or the propulsive-lift wing as it applies to lift, maneuverability, and short takeoff and landing. This hig...

J. C. Eppel D. W. Riddle V. C. Stevens

1988-01-01

124

Aircraft and avionic related research required to develop an effective high-speed runway exit system  

NASA Technical Reports Server (NTRS)

Research was conducted to increase airport capacity by studying the feasibility of the longitudinal separation between aircraft sequences on final approach. The multidisciplinary factors which include the utility of high speed exits for efficient runway operations were described along with recommendations and highlights of these studies.

Schoen, M. L.; Hosford, J. E.; Graham, J. M., Jr.; Preston, O. W.; Frankel, R. S.; Erickson, J. B.

1979-01-01

125

A Real-Time, Dual Processor Simulation of the Rotor System Research Aircraft.  

National Technical Information Service (NTIS)

A real-time, man-in-the loop, simulation of the rotor system research aircraft (RSRA) was conducted. The unique feature of this simulation was that two digital computers were used in parallel to solve the equations of the RSRA mathematical model. The desi...

D. B. Mackie T. S. Alderete

1977-01-01

126

Research Aircraft - Controlling Instruments from the Ground in a Secure and Authenticated Fashion  

NASA Astrophysics Data System (ADS)

At NCAR's Research Aviation Facility (RAF) we're finding a number of factors motivating the desire to be able to control instruments fielded on the aircraft we operate for the NSF. Investigators are increasingly interested in fielding greater numbers of research instruments for projects, instruments are becoming increasingly complicated, and adjustment of instrument behavior to adapt to changing conditions around the aircraft and to meet project goals are just a few of these factors. Usually there are not enough seats on the aircraft to accommodate all the instrument PIs and crew members who do occupy the seats are being asked to monitor and control increasing numbers of instruments about which they have limited knowledge. We use Satellite Communications (SatCom) to allow researchers to communicate with colleagues/crew on the aircraft and so that some of the real-time data can be sent to the ground for helping to optimize the research. Historically, challenges of authentication, security and the disruptive SatCom system have motivated us to avoid providing for remote instrument control. Now we have now reached an era where remote instrument control is a necessity. This poster will discuss the approach we are implementing to provide this capability for our instrument investigators. Particular attention is paid to how we assure authentication and security so that only the instrument investigators are capable of communicating with their instruments.;

Baltzer, T.; Martin, C.; Fawaz, S.; Webster, C.

2012-12-01

127

A research program to reduce the interior noise in general aviation aircraft, index and summary  

NASA Astrophysics Data System (ADS)

This report is an index of the published works from NASA Grant NSG 1301, entitled A Research Program to Reduce the Interior Noise in General Aviation Aircraft. Included are a list of all published reports and papers, a compilation of test specimen characteristics, and summaries of each published work.

Morgan, L.; Jackson, K.; Roskam, J.

1985-08-01

128

A research program to reduce the interior noise in general aviation aircraft, index and summary  

NASA Technical Reports Server (NTRS)

This report is an index of the published works from NASA Grant NSG 1301, entitled A Research Program to Reduce the Interior Noise in General Aviation Aircraft. Included are a list of all published reports and papers, a compilation of test specimen characteristics, and summaries of each published work.

Morgan, L.; Jackson, K.; Roskam, J.

1985-01-01

129

Flight Assessment of a Large Supersonic Drone Aircraft for Research Use.  

National Technical Information Service (NTIS)

An assessment is made of the capabilities of the BQM-34E supersonic drone aircraft as a test bed research vehicle. This assessment is made based on a flight conducted for the purpose of obtaining flight test measurements of wing loads at various maneuver ...

C. V. Eckstrom E. L. Peele

1974-01-01

130

All-electric aircraft: a systems view and proposed NASA research Programs  

SciTech Connect

It is expected that all-electric aircraft, whether military or commercial, will exhibit reduced weight, acquisition cost and fuel consumption, an expanded flight envelope and improved survivability and reliability, simpler maintenance, and reduced support equipment. Also noteworthy are dramatic improvements in mission adaptability, based on the degree to which control system performance relies on easily exchanged software. Flight-critical secondary power and control systems whose malfunction would mean loss of an aircraft pose failure detection and design methodology problems, however, that have only begun to be addressed. NASA-sponsored research activities concerned with these problems and prospective benefits are presently discussed.

Spitzer, C.R.

1984-05-01

131

Some applications of Hartmann-type sources in aircraft noise research  

NASA Astrophysics Data System (ADS)

Inflight shielding experiments were performed with a slender delta research aircraft fitted with needle stabilized generators having 19mm diameter driving jets operated from the high pressure turbine of the aircraft engine. Acoustic power output is 1 kW and consists of a strong fundamental 2.8 kHz tone and higher harmonics, discernible above engine noise. Comparative wind tunnel experiments employed quarter-scale versions built to match the tunnel model and these operated at 11 kHz, the output level being well above tunnel backgroung noise. Calibration in an anechoic room shows output to be steady and nearly omnidirectional.

Holbeche, T. A.; Jeffrey, R. W.

1980-11-01

132

The movement of water droplets in clouds around the nose of an atmospheric research aircraft  

NASA Technical Reports Server (NTRS)

The dynamic interaction between droplets and the airflow around the hemispherical nose of an aircraft was evaluated. The effect of the aircraft nose on droplet sampling for cloud research is explained. The proportion of different droplet sizes and their concentration at each point around the aircraft nose were determined. In a cloud, interaction between droplets is negligible. Each particle acts, for the calculation of the forces applied to it, as if it is alone in the air. The airflow carrying the droplets, on the average, is not influenced by their presence. The trajectory of each droplet was studied separately after calculating dry airflow. Concentrations were found with a Lagrangian method, using two trajectories computed directly close to one another. Theory confirms that to within 3% experimentally measured concentrations are representative of those in a cloud.

Feuillebois, P.; Scibilia, M. F.

1983-01-01

133

Longitudinal stability and control characteristics of the Quiet Short-Haul Research Aircraft (QSRA)  

NASA Technical Reports Server (NTRS)

Flight experiments were conducted to evaluate various aerodynamic characteristics of the Quiet Short-Haul Research Aircraft (QSRA), an experimental aircraft that makes use of the upper-surface blown (USB) powered-lift concept. Time-history records from maneuvers performed with the aircraft in landing-approach and take-off configurations (with its stability augmentation system disengaged) were analyzed to obtain longitudinal stability and control derivatives and performance characteristics. The experiments included measuring the aircraft responses to variations in the deflection of direct-lift control spoilers and to thrust variations as well as to elevator inputs. The majority of the results are given for the aircraft in a landing configuration with the USB flaps at 50 degrees. For this configuration, if the static longitudinal stability is defined as the variation of the pitching-moment coefficient with the lift coefficient at a constant thrust coefficient, this stability decreases significantly with increasing angle of attack above 9 degrees. For this configuration, at small and negative angles of attack and high levels of thrust, the elevators and the horizontal stabilizer lost effectiveness owing to incipent stalling, but this occurred only during unsteady maneuvers and for brief time intervals.

Stephenson, Jack D.; Hardy, Gordon H.

1989-01-01

134

Light Transport and General Aviation Aircraft Icing Research Requirements.  

National Technical Information Service (NTIS)

A short term and a long term icing research and technology program plan was drafted for NASA LeRC based on 33 separate research items. The specific items listed resulted from a comprehensive literature search, organized and assisted by a computer manageme...

R. K. Breeze G. M. Clark

1981-01-01

135

CV-990 Landing Systems Research Aircraft (LSRA) during final Space Shuttle tire test  

NASA Technical Reports Server (NTRS)

A Convair 990 (CV-990) was used as a Landing Systems Research Aircraft (LSRA) at NASA's Dryden Flight Research Center, Edwards, California, to test space shuttle landing gear and braking systems as part of NASA's effort to upgrade and improve space shuttle capabilities. The first flight at Dryden of the CV-990 with shuttle test components occurred in April 1993, and tests continued into August 1995, when this photo shows a test of the shuttle tires. The purpose of this series of tests was to determine the performance parameters and failure limits of the tires. This particular landing was on the dry lakebed at Edwards, but other tests occurred on the main runway there. The CV-990, built in 1962 by the Convair Division of General Dynamics Corp., Ft. Worth, Texas, served as a research aircraft at Ames Research Center, Moffett Field, California, before it came to Dryden.

1995-01-01

136

Studie om forskningsprosjekt vedroerende utslipp fra fly i oevre luftlag. (Study on research projects concerning aircraft emissions in the upper troposphere and lower stratosphere).  

National Technical Information Service (NTIS)

The report from NILU (Norwegian Institute for Air Research) relates to a study on the level of air pollution from aircraft emissions. The study covers an evaluation of finished, ongoing or planned research projects comprising the effects from aircraft emi...

A. G. Kraaboel F. Stordal

1996-01-01

137

Practical Application of a Subscale Transport Aircraft for Flight Research in Control Upset and Failure Conditions  

NASA Technical Reports Server (NTRS)

Over the past decade, the goal of reducing the fatal accident rate of large transport aircraft has resulted in research aimed at the problem of aircraft loss-of-control. Starting in 1999, the NASA Aviation Safety Program initiated research that included vehicle dynamics modeling, system health monitoring, and reconfigurable control systems focused on flight regimes beyond the normal flight envelope. In recent years, there has been an increased emphasis on adaptive control technologies for recovery from control upsets or failures including damage scenarios. As part of these efforts, NASA has developed the Airborne Subscale Transport Aircraft Research (AirSTAR) flight facility to allow flight research and validation, and system testing for flight regimes that are considered too risky for full-scale manned transport airplane testing. The AirSTAR facility utilizes dynamically-scaled vehicles that enable the application of subscale flight test results to full scale vehicles. This paper describes the modeling and simulation approach used for AirSTAR vehicles that supports the goals of efficient, low-cost and safe flight research in abnormal flight conditions. Modeling of aerodynamics, controls, and propulsion will be discussed as well as the application of simulation to flight control system development, test planning, risk mitigation, and flight research.

Cunningham, Kevin; Foster, John V.; Morelli, Eugene A.; Murch, Austin M.

2008-01-01

138

The NASA Dryden Flight Research Center Unmanned Aircraft System Service Capabilities  

NASA Technical Reports Server (NTRS)

Over 60 years of Unmanned Aircraft System (UAS) expertise at the National Aeronautics and Space Administration (NASA) Dryden Flight Research Center are being leveraged to provide capability and expertise to the international UAS community. The DFRC brings together technical experts, UAS, and an operational environment to provide government and industry a broad capability to conduct research, perform operations, and mature systems, sensors, and regulation. The cornerstone of this effort is the acquisition of both a Global Hawk (Northrop Grumman Corporation, Los Angeles, California) and Predator B (General Atomics Aeronautical Systems, Inc., San Diego, California) unmanned aircraft system (UAS). In addition, a test range for small UAS will allow developers to conduct research and development flights without the need to obtain approval from civil authorities. Finally, experts are available to government and industry to provide safety assessments in support of operations in civil airspace. These services will allow developers to utilize limited resources to their maximum capability in a highly competitive environment.

Bauer, Jeff

2007-01-01

139

The NASA Dryden Flight Research Center Unmanned Aircraft System Service Capabilities  

NASA Technical Reports Server (NTRS)

Over 60 years of Unmanned Aircraft System (UAS) expertise at the NASA Dryden Flight Research Center are being leveraged to provide capability and expertise to the international UAS community. The DFRC brings together technical experts, UAS, and an operational environment to provide government and industry a broad capability to conduct research, perform operations, and mature systems, sensors, and regulation. The cornerstone of this effort is the acquisition of both a Global Hawk (Northrop Grumman Corporation, Los Angeles, California) and Predator B (General Atomics Aeronautical Systems, Inc., San Diego, California) unmanned aircraft system (UAS). In addition, a test range for small UAS will allow developers to conduct research and development flights without the need to obtain approval from civil authorities. Finally, experts are available to government and industry to provide safety assessments in support of operations in civil airspace. These services will allow developers to utilize limited resources to their maximum capability in a highly competitive environment.

Bauer, Jeff

2007-01-01

140

Federal Interagency Committee on Aviation Noise (FICAN) Position on Research into Effects of Aircraft Noise on Classroom Learning.  

ERIC Educational Resources Information Center

This symposium report presents a summary of research on the affect of aircraft noise on the classroom environment revealing that aircraft noise can interfere with learning in the following areas: reading, motivation, language and speech acquisition, and memory. The strongest findings are in the area of reading, where more than 20 studies have…

2000

141

Integrated control and display research for transition and vertical flight on the NASA V/STOL Research Aircraft (VSRA)  

NASA Technical Reports Server (NTRS)

Results of a substantial body of ground-based simulation experiments indicate that a high degree of precision of operation for recovery aboard small ships in heavy seas and low visibility with acceptable levels of effort by the pilot can be achieved by integrating the aircraft flight and propulsion controls. The availability of digital fly-by-wire controls makes it feasible to implement an integrated control design to achieve and demonstrate in flight the operational benefits promised by the simulation experience. It remains to validate these systems concepts in flight to establish their value for advanced short takeoff vertical landing (STOVL) aircraft designs. This paper summarizes analytical studies and simulation experiments which provide a basis for the flight research program that will develop and validate critical technologies for advanced STOVL aircraft through the development and evaluation of advanced, integrated control and display concepts, and lays out the plan for the flight program that will be conducted on NASA's V/STOL Research Aircraft (VSRA).

Foster, John D.; Moralez, Ernesto, III; Franklin, James A.; Schroeder, Jeffery A.

1987-01-01

142

Flight testing the fixed-wing configuration of the Rotor Systems Research Aircraft (RSRA)  

NASA Technical Reports Server (NTRS)

The Rotor Systems Research Aircraft (RSRA) is a unique research aircraft designed to flight test advanced helicopter rotor system. Its principal flight test configuration is as a compound helicopter. The fixed wing configuration of the RSRA was primarily considered an energy fly-home mode in the event it became necessary to sever an unstable rotor system in flight. While it had always been planned to flight test the fixed wing configuration, the selection of the RSRA as the flight test bed for the X-wing rotor accelerated this schedule. This paper discusses the build-up to, and the test of, the RSRA fixed wing configuration. It is written primarily from the test pilot's perspective.

Hall, G. W.; Morris, P. M.

1985-01-01

143

NASA rotor system research aircraft flight-test data report: Helicopter and compound configuration  

NASA Technical Reports Server (NTRS)

The flight test activities of the Rotor System Research Aircraft (RSRA), NASA 740, from June 30, 1981 to August 5, 1982 are reported. Tests were conducted in both the helicopter and compound configurations. Compound tests reconfirmed the Sikorsky flight envelope except that main rotor blade bending loads reached endurance at a speed about 10 knots lower than previously. Wing incidence changes were made from 0 to 10 deg.

Erickson, R. E.; Kufeld, R. M.; Cross, J. L.; Hodge, R. W.; Ericson, W. F.; Carter, R. D. G.

1984-01-01

144

Flight assessment of a large supersonic drone aircraft for research use  

NASA Technical Reports Server (NTRS)

An assessment is made of the capabilities of the BQM-34E supersonic drone aircraft as a test bed research vehicle. This assessment is made based on a flight conducted for the purpose of obtaining flight test measurements of wing loads at various maneuver flight conditions. Flight plan preparation, flight simulation, and conduct of the flight test are discussed along with a presentation of the test data obtained and an evaluation of how closely the flight test followed the test plan.

Eckstrom, C. V.; Peele, E. L.

1974-01-01

145

WashingtonPost.com: Researchers Ape Nature With Flapping-Wing Aircraft  

NSDL National Science Digital Library

A Washington Post article from September 1, 2003 looks back at a significant moment in aviation when, in spring 2002, researchers successfully demonstrated an ornithopter capable of hovering. An ornithopter is a kind of aircraft that mimics flying creatures by using flapping wings instead of conventional propulsion systems. Many potential applications exist for future ornithopters, including Mars missions and military reconnaissance. September 12, 2003 NSDL MET Report.

Rajagopalan, Sumitra

146

Predesign study for a modern 4-bladed rotor for the NASA rotor systems research aircraft  

NASA Technical Reports Server (NTRS)

Trade-off study results and the rationale for the final selection of an existing modern four-bladed rotor system that can be adapted for installation on the Rotor Systems Research Aircraft (RSRA) are reported. The results of the detailed integration studies, parameter change studies, and instrumentation studies and the recommended plan for development and qualification of the rotor system is also given. Its parameter variants, integration on the RSRA, and support of ground and flight test programs are also discussed.

Bishop, H. E.; Burkam, J. E.; Heminway, R. C.; Keys, C. N.; Smith, K. E.; Smith, J. H.; Staley, J. A.

1981-01-01

147

Specially equipped aircraft used in Florida airborne field mill research  

NASA Technical Reports Server (NTRS)

CO2 study site manager and plant physiologist Graham Hymus (left) examines scrub oak foliage while project engineer David Johnson (right) looks on. The life sciences study is showing that rising levels of carbon dioxide in our atmosphere, caused by the burning of fossil fuels, could spur plant growth globally. The site of KSC's study is a natural scrub oak area near the Vehicle Assembly Building. Twelve-foot areas of scrub oak have been enclosed in 16 open-top test chambers into which CO2 has been blown. Five scientists from NASA and the Smithsonian Environmental Research Center in Edgewater, Md., work at the site to monitor experiments and keep the site running. Scientists hope to continue the study another five to 10 years. More information on this study can be found in Release No. 57- 00. Additional photos can be found at: www- pao.ksc.nasa.gov/captions/subjects/co2study.htm

2000-01-01

148

Aircraft flight flutter testing at the NASA Ames-Dryden Flight Research Facility  

NASA Technical Reports Server (NTRS)

Many parameter identification techniques have been used at the NASA Ames Research Center, Dryden Research Facility at Edwards Air Force Base to determine the aeroelastic stability of new and modified research vehicles in flight. This paper presents a summary of each technique used with emphasis on fast Fourier transform methods. Experiences gained from application of these techniques to various flight test programs are discussed. Also presented are data-smoothing techniques used for test data distorted by noise. Data are presented for various aircraft to demonstrate the accuracy of each parameter identification technique discussed.

Kehoe, Michael W.

1988-01-01

149

Overview of Fundamental High-Lift Research for Transport Aircraft at NASA  

NASA Technical Reports Server (NTRS)

NASA has had a long history in fundamental and applied high lift research. Current programs provide a focus on the validation of technologies and tools that will enable extremely short take off and landing coupled with efficient cruise performance, simple flaps with flow control for improved effectiveness, circulation control wing concepts, some exploration into new aircraft concepts, and partnership with Air Force Research Lab in mobility. Transport high-lift development testing will shift more toward mid and high Rn facilities at least until the question: "How much Rn is required" is answered. This viewgraph presentation provides an overview of High-Lift research at NASA.

Leavitt, L. D.; Washburn, A. E.; Wahls, R. A.

2007-01-01

150

Research Pilot Milt Thompson in M2-F2 Aircraft Attached to B-52 Mothership  

NASA Technical Reports Server (NTRS)

NASA research pilot Milt Thompson sits in the M2-F2 'heavyweight' lifting body research vehicle before a 1966 test flight. The M2-F2 and the other lifting-body designs were all attached to a wing pylon on NASA's B-52 mothership and carried aloft. The vehicles were then drop-launched and, at the end of their flights, glided back to wheeled landings on the dry lake or runway at Edwards AFB. The lifting body designs influenced the design of the Space Shuttle and were also reincarnated in the design of the X-38 in the 1990s. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most significant research projects in aerospace history. Some of the significant projects supported by B-52 008 include the X-15, the lifting bodies, HiMAT (highly maneuverable aircraft technology), Pegasus, validation of parachute systems developed for the space shuttle program (solid-rocket-booster recovery system and the orbiter drag chute system), and the X-38. The B-52 served as the launch vehicle on 106 X-15 flights and flew a total of 159 captive-carry and launch missions in support of that program from June 1959 to October 1968. Information gained from the highly successful X-15 program contributed to the Mercury, Gemini, and Apollo human spaceflight programs as well as space shuttle development. Between 1966 and 1975, the B-52 served as the launch aircraft for 127 of the 144 wingless lifting body flights. In the 1970s and 1980s, the B-52 was the launch aircraft for several aircraft at what is now the Dryden Flight Research Center, Edwards, California, to study spin-stall, high-angle-of attack, and maneuvering characteristics. These included the 3/8-scale F-15/spin research vehicle (SRV), the HiMAT (Highly Maneuverable Aircraft Technology) research vehicle, and the DAST (drones for aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

1966-01-01

151

Performance of an Electro-Hydrostatic Actuator on the F-18 Systems Research Aircraft  

NASA Technical Reports Server (NTRS)

An electro-hydrostatic actuator was evaluated at NASA Dryden Flight Research Center, Edwards, California. The primary goal of testing this actuator system was the flight demonstration of power-by-wire technology on a primary flight control surface. The electro-hydrostatic actuator uses an electric motor to drive a hydraulic pump and relies on local hydraulics for force transmission. This actuator replaced the F-18 standard left aileron actuator on the F-18 Systems Research Aircraft and was evaluated throughout the Systems Research Aircraft flight envelope. As of July 24, 1997 the electro-hydrostatic actuator had accumulated 23.5 hours of flight time. This paper presents the electro-hydrostatic actuator system configuration and component description, ground and flight test plans, ground and flight test results, and lessons learned. This actuator performs as well as the standard actuator and has more load capability than required by aileron actuator specifications of McDonnell- Douglas Aircraft, St. Louis, Missouri. The electro-hydrostatic actuator system passed all of its ground tests with the exception of one power-off test during unloaded dynamic cycling.

Navarro, Robert

1997-01-01

152

Simulation evaluation of the control system command monitoring concept for the NASA V/STOL research aircraft (VSRA)  

NASA Technical Reports Server (NTRS)

A control-system monitoring concept is described that has the potential of rapidly detecting computer command failures (hardware or software) in fly-by-wire control systems. The concept has been successfully tested on the NASA Vertical/Short Takeoff and Landing Research Aircraft (VSRA) in the Ames Research Center's Vertical Motion Simulator. The test was particularly stringent, since the VSRA is required to operate in a hazardous environment. The fidelity of the aircraft model used in the simulation was verified by flying both the simulated and actual aircraft in a precision hover task using specially designed targets.

Schroeder, J. A.; Moralez, E.; Merrick, V. K.

1987-01-01

153

Experimental aerodynamic characteristics of a joined-wing research aircraft configuration  

NASA Technical Reports Server (NTRS)

A wind-tunnel test was conducted at Ames Research Center to measure the aerodynamic characteristics of a joined-wing research aircraft (JWRA). This aircraft was designed to utilize the fuselage and engines of the existing NASA AD-1 aircraft. The JWRA was designed to have removable outer wing panels to represent three different configurations with the interwing joint at different fractions of the wing span. A one-sixth-scale wind-tunnel model of all three configurations of the JWRA was tested in the Ames 12-Foot Pressure Wind Tunnel to measure aerodynamic performance, stability, and control characteristics. The results of these tests are presented. Longitudinal and lateral-directional characteristics were measured over an angle of attack range of -7 to 14 deg and over an angle of sideslip range of -5 to +2.5 deg at a Mach number of 0.35 and a Reynolds number of 2.2x10(6)/ft. Various combinations of deflected control surfaces were tested to measure the effectiveness and impact on stability of several control surface arrangements. In addition, the effects on stall and post-stall aerodynamic characteristics from small leading-edge devices called vortilons were measured. The results of these tests indicate that the JWRA had very good aerodynamic performance and acceptable stability and control throughout its flight envelope. The vortilons produced a profound improvement in the stall and post-stall characteristics with no measurable effects on cruise performance.

Smith, Stephen C.; Stonum, Ronald K.

1989-01-01

154

Flight Test Experience With an Electromechanical Actuator on the F-18 Systems Research Aircraft  

NASA Technical Reports Server (NTRS)

Development of reliable power-by-wire actuation systems for both aeronautical and space applications has been sought recently to eliminate hydraulic systems from aircraft and spacecraft and thus improve safety, efficiency, reliability, and maintainability. The Electrically Powered Actuation Design (EPAD) program was a joint effort between the Air Force, Navy, and NASA to develop and fly a series of actuators validating power-by-wire actuation technology on a primary flight control surface of a tactical aircraft. To achieve this goal, each of the EPAD actuators was installed in place of the standard hydraulic actuator on the left aileron of the NASA F/A-18B Systems Research Aircraft (SRA) and flown throughout the SRA flight envelope. Numerous parameters were recorded, and overall actuator performance was compared with the performance of the standard hydraulic actuator on the opposite wing. This paper discusses the integration and testing of the EPAD electromechanical actuator (EMA) on the SRA. The architecture of the EMA system is discussed, as well as its integration with the F/A-18 Flight Control System. The flight test program is described, and actuator performance is shown to be very close to that of the standard hydraulic actuator it replaced. Lessons learned during this program are presented and discussed, as well as suggestions for future research.

Jensen, Stephen C.; Jenney, Gavin D.; Raymond, Bruce; Dawson, David

2000-01-01

155

Flight Test Experience with an Electromechanical Actuator on the F-18 Systems Research Aircraft  

NASA Technical Reports Server (NTRS)

Development of reliable power-by-wire actuation systems for both aeronautical and space applications has been sought recently to eliminate hydraulic systems from aircraft and spacecraft and thus improve safety, efficiency, reliability, and maintainability. The Electrically Powered Actuation Design (EPAD) program was a joint effort between the Air Force, Navy, and NASA to develop and fly a series of actuators validating power-by-wire actuation technology on a primary flight control surface of a tactical aircraft. To achieve this goal, each of the EPAD actuators was installed in place of the standard hydraulic actuator on the left aileron of the NASA F/A-18B Systems Research Aircraft (SRA) and flown throughout the SRA flight envelope. Numerous parameters were recorded, and overall actuator performance was compared with the performance of the standard hydraulic actuator on the opposite wing. This paper discusses the integration and testing of the EPAD electromechanical actuator (EMA) on the SRA. The architecture of the EMA system is discussed, as well as its integration with the F/A-18 Flight Control System. The flight test program is described, and actuator performance is shown to be very close to that of the standard hydraulic actuator it replaced. Lessons learned during this program are presented and discussed, as well as suggestions for future research.

Jensen, Stephen C.; Jenney, Gavin D.; Raymond, Bruce; Dawson, David; Flick, Brad (Technical Monitor)

2000-01-01

156

Advanced AFCS developments on the XV-15 tilt rotor research aircraft. [Automatic Flight Control System  

NASA Technical Reports Server (NTRS)

The design criteria and control and handling qualities of the Automatic Flight Control System (AFCS), developed in the framework of the XV-15 tilt-rotor research aircraft, are evaluated, differentiating between the stability and control criteria. A technically aggressive SCAS control law was implemented, demonstrating that significant benefits accrue when stability criteria are separated from design criteria; the design analyses for application of the control law are presented, and the limit bandwidth for stabilization in hovering flight is shown to be defined by rotor or control lag functions. Flight tests of the aircraft resulted in a rating of 3 on the Cooper-Harper scale; a possibility of achieving a rating of 2 is expected if the system is applied to the yaw and heave control modes.

Churchill, G. B.; Gerdes, R. M.

1984-01-01

157

Dynamic structural aeroelastic stability testing of the XV-15 tilt rotor research aircraft  

NASA Technical Reports Server (NTRS)

For the past 20 years, a significant effort has been made to understand and predict the structural aeroelastic stability characteristics of the tilt rotor concept. Beginning with the rotor-pylon oscillation of the XV-3 aircraft, the problem was identified and then subjected to a series of theoretical studies, plus model and full-scale wind tunnel tests. From this data base, methods were developed to predict the structural aeroelastic stability characteristics of the XV-15 Tilt Rotor Research Aircraft. The predicted aeroelastic characteristics are examined in light of the major parameters effecting rotor-pylon-wing stability. Flight test techniques used to obtain XV-15 aeroelastic stability are described. Flight test results are summarized and compared to the predicted values. Wind tunnel results are compared to flight test results and correlated with predicted values.

Schroers, L. G.

1982-01-01

158

Static noise tests on augmentor wing jet STOL research aircraft (C8A Buffalo)  

NASA Technical Reports Server (NTRS)

Results are presented for full scale ground static acoustic tests of over-area conical nozzles and a lobe nozzle installed on the Augmentor Wing Jet STOL Research Aircraft, a modified C8A Buffalo. The noise levels and spectrums of the test nozzles are compared against those of the standard conical nozzle now in use on the aircraft. Acoustic evaluations at 152 m (500 ft), 304 m (1000 ft), and 1216 m (4000 ft) are made at various engine power settings with the emphasis on approach and takeoff power. Appendix A contains the test log and propulsion calculations. Appendix B gives the original test plan, which was closely adhered to during the test. Appendix C describes the acoustic data recording and reduction systems, with calibration details.

Marrs, C. C.; Harkonen, D. L.; Okeefe, J. V.

1974-01-01

159

A real-time, dual processor simulation of the rotor system research aircraft  

NASA Technical Reports Server (NTRS)

A real-time, man-in-the loop, simulation of the rotor system research aircraft (RSRA) was conducted. The unique feature of this simulation was that two digital computers were used in parallel to solve the equations of the RSRA mathematical model. The design, development, and implementation of the simulation are documented. Program validation was discussed, and examples of data recordings are given. This simulation provided an important research tool for the RSRA project in terms of safe and cost-effective design analysis. In addition, valuable knowledge concerning parallel processing and a powerful simulation hardware and software system was gained.

Mackie, D. B.; Alderete, T. S.

1977-01-01

160

Comparison of Profiling Microwave Radiometer, Aircraft, and Radiosonde Measurements From the Alliance Icing Research Study (AIRS)  

NASA Technical Reports Server (NTRS)

Measurements from a profiling microwave radiometer are compared to measurements from a research aircraft and radiosondes. Data compared is temperature, water vapor, and liquid water profiles. Data was gathered at the Alliance Icing Research Study (AIRS) at Mirabel Airport outside Montreal, Canada during December 1999 and January 2000. All radiometer measurements were found to lose accuracy when the radome was wet. When the radome was not wetted, the radiometer was seen to indicate an inverted distribution of liquid water within a cloud. When the radiometer measurements were made at 15 deg. instead of the standard zenith, the measurements were less accurate.

Reehorst, Andrew L.

2001-01-01

161

The Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) Concept and Research  

NASA Technical Reports Server (NTRS)

The ability to conduct concurrent, multiple aircraft operations in poor weather at virtually any airport offers an important opportunity for a significant increase in the rate of flight operations, a major improvement in passenger convenience, and the potential to foster growth of operations at small airports. The Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept is designed to increase capacity at the 3400 non-radar, non-towered airports in the United States where operations are currently restricted to one-in/one-out procedural separation during low visibility or ceilings. The concept s key feature is that pilots maintain their own separation from other aircraft using air-to-air datalink and on-board software within the Self-Controlled Area (SCA), an area of flight operations established during poor visibility and low ceilings around an airport without Air Traffic Control (ATC) services. While pilots self-separate within the SCA, an Airport Management Module (AMM) located at the airport assigns arriving pilots their sequence based on aircraft performance, position, winds, missed approach requirements, and ATC intent. The HVO design uses distributed decision-making, safe procedures, attempts to minimize pilot and controller workload, and integrates with today's ATC environment. The HVO procedures have pilots make their own flight path decisions when flying in Instrument Metrological Conditions (IMC) while meeting these requirements. This paper summarizes the HVO concept and procedures, presents a summary of the research conducted and results, and outlines areas where future HVO research is required. More information about SATS HVO can be found at http://ntrs.nasa.gov.

Baxley, B.; Williams, D.; Consiglio, M.; Adams, C.; Abbott, T.

2005-01-01

162

The SR-71 Test Bed Aircraft: A Facility for High-Speed Flight Research  

NASA Technical Reports Server (NTRS)

The SR-71 test bed aircraft is shown to be a unique platform to flight-test large experiments to supersonic Mach numbers. The test bed hardware mounted on the SR-71 upper fuselage is described. This test bed hardware is composed of a fairing structure called the "canoe" and a large "reflection plane" flat plate for mounting experiments. Total experiment weights, including the canoe and reflection plane, as heavy as 14,500 lb can be mounted on the aircraft and flight-tested to speeds as fast as Mach 3.2 and altitudes as high as 80,000 ft. A brief description of the SR-71 aircraft is given, including details of the structural modifications to the fuselage, modifications to the J58 engines to provide increased thrust, and the addition of a research instrumentation system. Information is presented based on flight data that describes the SR-71 test bed aerodynamics, stability and control, structural and thermal loads, the canoe internal environment, and reflection plane flow quality. Guidelines for designing SR-71 test bed experiments are also provided.

Corda, Stephen; Moes, Timothy R.; Mizukami, Masashi; Hass, Neal E.; Jones, Daniel; Monaghan, Richard C.; Ray, Ronald J.; Jarvis, Michele L.; Palumbo, Nathan

2000-01-01

163

Application of the Remotely Piloted Aircraft (RPA) 'MASC' in Atmospheric Boundary Layer Research  

NASA Astrophysics Data System (ADS)

The remotely piloted aircraft (RPA) MASC (Multipurpose Airborne Sensor Carrier) was developed at the University of Tübingen in cooperation with the University of Stuttgart, University of Applied Sciences Ostwestfalen-Lippe and 'ROKE-Modelle'. Its purpose is the investigation of thermodynamic processes in the atmospheric boundary layer (ABL), including observations of temperature, humidity and wind profiles, as well as the measurement of turbulent heat, moisture and momentum fluxes. The aircraft is electrically powered, has a maximum wingspan of 3.40 m and a total weight of 5-8 kg, depending on battery- and payload. The standard meteorological payload consists of temperature sensors, a humidity sensor, a flow probe, an inertial measurement unit and a GNSS. In normal operation, the aircraft is automatically controlled by the ROCS (Research Onboard Computer System) autopilot to be able to fly predefined paths at constant altitude and airspeed. Since 2010 the system has been tested and improved intensively. In September 2012 first comparative tests could successfully be performed at the Lindenberg observatory of Germany's National Meteorological Service (DWD). In 2013, several campaigns were done with the system, including fundamental boundary layer research, wind energy meteorology and assistive measurements to aerosol investigations. The results of a series of morning transition experiments in summer 2013 will be presented to demonstrate the capabilities of the measurement system. On several convective days between May and September, vertical soundings were done to record the evolution of the ABL in the early morning, from about one hour after sunrise, until noon. In between the soundings, flight legs of up to 1 km length were performed to measure turbulent statistics and fluxes at a constant altitude. With the help of surface flux measurements of a sonic anemometer, methods of similarity theory could be applied to the RPA flux measurements to compare them to literature. The results show prospects and limitations of boundary layer research with a single RPA at the present state of the art.

Wildmann, Norman; Bange, Jens

2014-05-01

164

Variable pitch fan system for NASA/Navy research and technology aircraft  

NASA Technical Reports Server (NTRS)

Preliminary design of a shaft driven, variable-pitch lift fan and lift-cruise fan was conducted for a V/STOL Research and Technology Aircraft. The lift fan and lift-cruise fan employed a common rotor of 157.5 cm diameter, 1.18 pressure ratio variable-pitch fan designed to operate at a rotor-tip speed of 284 mps. Fan performance maps were prepared and detailed aerodynamic characteristics were established. Cost/weight/risk trade studies were conducted for the blade and fan case. Structural sizing was conducted for major components and weights determined for both the lift and lift-cruise fans.

Ryan, W. P.; Black, D. M.; Yates, A. F.

1977-01-01

165

Free float acceleration measurements aboard NASA's KC-135 Microgravity Research Aircraft  

NASA Technical Reports Server (NTRS)

A three-axis accelerometer subsystem, developed as part of a get-away-special Ga-As crystal growth system for the Space Shuttle, is described. Each axis of this subsystem contains a quartz flexure accelerometer capable of dc measurements, custom-designed measurement circuitry, a programmable microcomputer for measurement control and data reduction, and memory for recording data. The subsystem was flown as a free float experiment aboard the NASA KC-135 microgravity research aircraft, yielding measurements of accelerations during free float at a resolution of 10 micro-g.

Bellows, A. H.; Matthiesen, D. H.; Duchene, G. A.

1990-01-01

166

MASC - a small Remotely Piloted Aircraft (RPA) for wind energy research  

NASA Astrophysics Data System (ADS)

Originally designed for atmospheric boundary layer research, the MASC (Multipurpose Airborne Sensor Carrier) RPA (Remotely Piloted Aircraft, also known as Unmanned Aerial Vehicle, UAV) is capable of making in-situ measurements of temperature, humidity and wind in high resolution and precision. The autopilot system ROCS (Research Onboard Computer System) enables the aircraft to fly pre-defined routes between waypoints at constant altitude and airspeed. The system manages to operate in wind speeds up to 15 m s-1 safely. It is shown that a MASC can fly as close as one rotor diameter upstream and downstream of running wind turbines at these wind speeds and take valuable data of incoming flow and wake. The flexible operation of an RPA at the size of a MASC can be a major advantage of the system compared to tower measurements and remote sensing in wind energy research. In the project "Lidar Complex" comparisons of RPA measurements with lidar systems and tower measurements are carried out at two different test sites. First results, including turbulence and wake measurements, from a campaign in autumn 2013 are presented.

Wildmann, N.; Hofsäß, M.; Weimer, F.; Joos, A.; Bange, J.

2014-05-01

167

A preliminary intercomparison between numerical upper wind forecasts and research aircraft measurements of jet streams  

NASA Technical Reports Server (NTRS)

During the past several years, research on the structure of extra-tropical jet streams has been carried out with direct measurements with instrumented research aircraft from the National Center for Atmospheric Research (NCAR). These measurements have been used to describe the wind, temperature, turbulence and chemical characteristics of jet streams. A fundamental question is one of assessing the potential value of existing operational numerical forecast models for forecasting the meteorological conditions along commercial aviation flight routes so as to execute Minimum Flight Time tracks and thus obtain the maximum efficiency in aviation fuel consumption. As an initial attempt at resolving this question, the 12 hour forecast output from two models was expressed in terms of a common output format to ease their intercomparison. The chosen models were: (1) the Fine-Mesh Spectral hemispheric and (2) the Limited Area Fine Mesh (LFM) model.

Shapiro, M. A.

1982-01-01

168

Dryden Research Aircraft Fleet on Ramp - 1993, X-15, F-18, SR-71, X-31, X-29  

NASA Technical Reports Server (NTRS)

A group photo of research aircraft at NASA's Ames/Dryden Flight Research Facility in 1993 (redesignated the Dryden Flight Research Center in 1994). Left to right: mock-up of X-15, F-18B, SR-71A, X-31, and X-29. The X-15 mock-up is painted as the #3 aircraft, which was lost on November 15, 1967, in an accident that resulted in the death of Air Force Major Mike Adams. The mock-up is now (2001) atop a pole in front of Dryden's main gate. The two-seat F-18B was in use around the turn of the 20th into the 21st century as a chase aircraft for a variety of projects. The SR-71 was one of several transferred to NASA after the aircraft was retired by the Air Force. The X-31 was designed to test flight at high angles of attack using thrust vectoring. The X-29 served as a testbed for forward swept wings. These aircraft and mock-up suggest the great variety of flight research that Dryden Flight Research Center and its predecessor organizations have conducted over more than 50 years since 1946.

1993-01-01

169

NASA rotor systems research aircraft: Fixed-wing configuration flight-test results  

NASA Technical Reports Server (NTRS)

The fixed-wing, airplane configuration flight-test results of the Rotor System Research Aircraft (RSRA), NASA 740, at Ames/Dryden Flight Research Center are documented. Fourteen taxi and flight tests were performed from December 1983 to October 1984. This was the first time the RSRA was flown with the main rotor removed; the tail rotor was installed. These tests confirmed that the RSRA is operable as a fixed-wing aircraft. Data were obtained for various takeoff and landing distances, control sensitivity, trim and dynamics stability characteristics, performance rotor-hub drag, and acoustics signature. Stability data were obtained with the rotor hub both installed and removed. The speed envelope was developed to 261 knots true airspeed (KTAS), 226 knots calibrated airspeed (KCAS) at 10,000 ft density altitude. The airplane was configured at 5 deg. wing incidence with 5 deg. wing flaps as a normal configuration. Level-flight data were acquired at 167 KCAS for wing incidence from 0 to 10 deg. Step inputs and doublet inputs of various magnitudes were utilized to acquire dynamic stability and control sensitivity data. Sine-wave inputs of constantly increasing frequency were used to generate parameter identification data. The maximum load factor attained was 2.34 g at 206 KCAS.

Erickson, R. E.; Cross, J. L.; Kufeld, R. M.; Acree, C. W.; Nguyen, D.; Hodge, R. W.

1986-01-01

170

PTR-MS Measurements From the BAe-146 Research Aircraft During the ICARTT Campaign  

NASA Astrophysics Data System (ADS)

A Proton Transfer Reaction Mass Spectrometer (PTR-MS) has been adapted for use on the new UK Research Aircraft (BAe Systems 146, FAAM) and took part in the multi-national ICARTT (International Consortium for Atmospheric Research on Transport and Transformation) experiment in the summer of 2004, with the aim of studying chemical processing as pollution is transported away from source regions. The PTR-MS method is based on proton transfer reactions of H3O+ ions with volatile organic compounds (VOCs) and is capable of monitoring VOCs in near real time with detection limits of a few tens of pptv. Flying out of Horta airport (Faial Island, Azores), the aircraft frequently intercepted plumes of pollution emanating from the North American continent, some of which were heavily impacted by the Alaskan forest fires. Compounds measured include methanol, acetonitrile, acetaldehyde, acetone, benzene and toluene. Data will be presented to include vertical profiles and comparisons with CO, O3 and other tracers. The in situ PTR-MS measurements will also be compared with VOC/OVOC data from bottle samples which were collected during flight and analysed using gas chromatography.

Hulse, A.; Oram, D. E.; Reeves, C. E.; Penkett, S. A.; Lewis, A. C.; Hopkins, J. R.; Watson, N. M.; Methven, J.; Purvis, R.

2005-12-01

171

An Evaluation Technique for an F/A-18 Aircraft Loads Model Using F/A-18 Systems Research Aircraft Flight Data  

NASA Technical Reports Server (NTRS)

A limited evaluation of the F/A-18 baseline loads model was performed on the Systems Research Aircraft at NASA Dryden Flight Research Center (Edwards, California). Boeing developed the F/A-18 loads model using a linear aeroelastic analysis in conjunction with a flight simulator to determine loads at discrete locations on the aircraft. This experiment was designed so that analysis of doublets could be used to establish aircraft aerodynamic and loads response at 20 flight conditions. Instrumentation on the right outboard leading edge flap, left aileron, and left stabilator measured the hinge moment so that comparisons could be made between in-flight-measured hinge moments and loads model-predicted values at these locations. Comparisons showed that the difference between the loads model-predicted and in-flight-measured hinge moments was up to 130 percent of the flight limit load. A stepwise regression technique was used to determine new loads derivatives. These derivatives were placed in the loads model, which reduced the error to within 10 percent of the flight limit load. This paper discusses the flight test methodology, a process for determining loads coefficients, and the direct comparisons of predicted and measured hinge moments and loads coefficients.

Olney, Candida D.; Hillebrandt, Heather; Reichenbach, Eric Y.

2000-01-01

172

Scaled Composites' Proteus aircraft and an F/A-18 Hornet from NASA's Dryden Flight Research Center d  

NASA Technical Reports Server (NTRS)

Scaled Composites' Proteus aircraft and an F/A-18 Hornet from NASA's Dryden Flight Research Center during a low-level flyby at Las Cruces Airport in New Mexico. The unique Proteus aircraft served as a test bed for NASA-sponsored flight tests designed to validate collision-avoidance technologies proposed for uninhabited aircraft. The tests, flown over southern New Mexico in March, 2002, used the Proteus as a surrogate uninhabited aerial vehicle (UAV) while three other aircraft flew toward the Proteus from various angles on simulated collision courses. Radio-based 'detect, see and avoid' equipment on the Proteus successfully detected the other aircraft and relayed that information to a remote pilot on the ground at Las Cruces Airport. The pilot then transmitted commands to the Proteus to maneuver it away from the potential collisions. The flight demonstration, sponsored by NASA Dryden Flight Research Center, New Mexico State University, Scaled Composites, the U.S. Navy and Modern Technology Solutions, Inc., were intended to demonstrate that UAVs can be flown safely and compatibly in the same skies as piloted aircraft.

2002-01-01

173

Lateral-directional stability and control characteristics of the Quiet Short-Haul Research Aircraft (QSRA)  

NASA Technical Reports Server (NTRS)

The results are presented of flight experiments to determine the lateral-directional stability and control characteristics of the Quiet Short-Haul Research Aircraft (QSRA), an experimental aircraft designed to furnish information on various aerodynamic characteristics of a transport type of airplane that makes use of the upper-surface blown (USB) flap technology to achieve short takeoff and landing (STOL) performance. The flight program designed to acquire the data consisted of maneuvers produced by rudder and control-wheel inputs with the airplane in several configurations that had been proposed for landing approach and takeoff operation. The normal stability augmentation system was not engaged during these maneuvers. Time-history records from the maneuvers were analyzed with a parameter estimation procedure to extract lateral-directional stability and control derivatives. For one aircraft configuration in which the USB flaps were deflected 50 deg, several maneuvers were performed to determine the effects of varying the average angle of attack, varying the thrust coefficient, and setting the airplane's upper surface spoilers at a 13 deg symmetrical bias angle . The effects on the lateral characteristics of deflecting the spoilers were rather small and generally favorable. The data indicate that for one test, conducted at low thrust (a thrust coefficient of 0.38), compared with results from tests at thrust coefficients of 0.77 and larger, there was a significant decrease in the lateral control effectiveness, in the yaw damping and in the directional derivative. The directional derivative was also decreased (by about 30 percent) when the average angle of attack of the test was increased from 3 to 16 deg.

Stephenson, Jack D.; Jeske, James A.; Hardy, Gordon H.

1990-01-01

174

Efficient, Low-Cost Fan System Research for General Aviation and Commuter Aircraft  

NASA Technical Reports Server (NTRS)

This document reports research investigations into efficient, low-cost fan system concepts for high bypass turbofans for future general aviation and commuter aircraft. The research specifically addressed lower pressure ratio fans for good propulsive efficiencies in the 200 to 400 knot flight speed regime. Aerodynamic design analyses yielded predicted efficiency in area of 91 to 92 percent (adiabatic). Low-cost manufacturing studies yielded an aluminum blisk rotor and investment cast stator having lowest cost. Structural design analyses yielded a design having excellent vibratory characteristics and the ability to pass One- and Four-pound bird strikes satisfactorily. The low speed and low pressure fans of the study are estimated to have 24 to 30 EPNdB lower community noise levels than larger, high pressure ratio transonic fans.

Merrill, G. L.

2003-01-01

175

Gravity-Dependent Combustion and Fluids Research - From Drop Towers to Aircraft to the ISS  

NASA Technical Reports Server (NTRS)

Driven by the need for knowledge related to the low-gravity environment behavior of fluids in liquid fuels management, thermal control systems and fire safety for spacecraft, NASA embarked on a decades long research program to understand, accommodate and utilize the relevant phenomena. Beginning in the 1950s, and continuing through to today, drop towers and aircraft were used to conduct an ever broadening and increasingly sophisticated suite of experiments designed to elucidate the underlying gravity-dependent physics that drive these processes. But the drop towers and aircraft afford only short time periods of continuous low gravity. Some of the earliest rocket test flights and manned space missions hosted longer duration experiments. The relatively longer duration low-g times available on the space shuttle during the 1980s and 1990s enabled many specialized experiments that provided unique data for a wide range of science and engineering disciplines. Indeed, a number of STS-based Spacelab missions were dedicated solely to basic and applied microgravity research in the biological, life and physical sciences. Between 1980 and 2000, NASA implemented a vigorous Microgravity Science Program wherein combustion science and fluid physics were major components. The current era of space stations from the MIR to the International Space Station have opened up a broad range of opportunities and facilities that are now available to support both applied research for technologies that will help to enable the future exploration missions and for a continuation of the non-exploration basic research that began over fifty years ago. The ISS-based facilities of particular value to the fluid physics and combustion/fire safety communities are the Fluids and Combustion Facility Combustion Integrated Rack and the Fluids Integrated Rack.

Urban, David L.; Singh, Bhim S.; Kohl, Fred J.

2007-01-01

176

CV-990 Landing Systems Research Aircraft (LSRA) flight #145 drilling of shuttle tire using Tire Assa  

NASA Technical Reports Server (NTRS)

Created from a 1/16th model of a German World War II tank, the TAV (Tire Assault Vehicle) was an important safety feature for the Convair 990 Landing System Research Aircraft, which tested space shuttle tires. It was imperative to know the extreme conditions the shuttle tires could tolerate at landing without putting the shuttle and its crew at risk. In addition, the CV990 was able to land repeatedly to test the tires. The TAV was built from a kit and modified into a radio controlled, video-equipped machine to drill holes in aircraft test tires that were in imminent danger of exploding because of one or more conditions: high air pressure, high temperatures, and cord wear. An exploding test tire releases energy equivalent to two and one-half sticks of dynamite and can cause severe injuries to anyone within 50 ft. of the explosion, as well as ear injury - possibly permanent hearing loss - to anyone within 100 ft. The degree of danger is also determined by the temperature pressure and cord wear of a test tire. The TAV was developed by David Carrott, a PRC employee under contract to NASA.

1995-01-01

177

Interior and exterior fuselage noise measured on NASA's C-8a augmentor wing jet-STOL research aircraft  

NASA Technical Reports Server (NTRS)

Interior and exterior fuselage noise levels were measured on NASA's C-8A Augmentor Wing Jet-STOL Research Aircraft in order to provide design information for the Quiet Short-Haul Research Aircraft (QSRA), which will use a modified C-8A fuselage. The noise field was mapped by 11 microphones located internally and externally in three areas: mid-fuselage, aft fuselage, and on the flight deck. Noise levels were recorded at four power settings varying from takeoff to flight idle and were plotted in one-third octave band spectra. The overall sound pressure levels of the external noise field were compared to previous tests and found to correlate well with engine primary thrust levels. Fuselage values were 145 + or - 3 dB over the aircraft's normal STOL operating range.

Shovlin, M. D.

1977-01-01

178

Development of test methods for scale model simulation of aerial applications in the NASA Langley Vortex Research Facility. [agricultural aircraft  

NASA Technical Reports Server (NTRS)

As part of basic research to improve aerial applications technology, methods were developed at the Langley Vortex Research Facility to simulate and measure deposition patterns of aerially-applied sprays and granular materials by means of tests with small-scale models of agricultural aircraft and dynamically-scaled test particles. Interactions between the aircraft wake and the dispersed particles are being studied with the objective of modifying wake characteristics and dispersal techniques to increase swath width, improve deposition pattern uniformity, and minimize drift. The particle scaling analysis, test methods for particle dispersal from the model aircraft, visualization of particle trajectories, and measurement and computer analysis of test deposition patterns are described. An experimental validation of the scaling analysis and test results that indicate improved control of chemical drift by use of winglets are presented to demonstrate test methods.

Jordan, F. L., Jr.

1980-01-01

179

Upper surface blowing noise of the NASA-Ames quiet short-haul research aircraft  

NASA Technical Reports Server (NTRS)

An experimental study of the propulsive-lift noise of the NASA-Ames quiet short-haul research aircraft (QSRA) is described. Comparisons are made of measured QSRA flyover noise and model propulsive-lift noise data available in references. Developmental tests of trailing-edge treatments were conducted using sawtooth-shaped and porous USB flap trailing-edge extensions. Small scale parametric tests were conducted to determine noise reduction/design relationships. Full-scale static tests were conducted with the QSRA preparatory to the selection of edge treatment designs for flight testing. QSRA flight and published model propulsive-lift noise data have similar characteristics. Noise reductions of 2 to 3 dB were achieved over a wide range of frequency and directivity angles in static tests of the QSRA. These noise reductions are expected to be achieved or surpassed in flight tests planned by NASA in 1980.

Bohn, A. J.; Shovlin, M. D.

1980-01-01

180

Simulation validation of the XV-15 tilt-rotor research aircraft  

NASA Technical Reports Server (NTRS)

The results of a simulation validation program of the XV-15 tilt-rotor research aircraft are detailed, covering such simulation aspects as the mathematical model, visual system, motion system, cab aural system, cab control loader system, pilot perceptual fidelity, and generic tilt rotor applications. Simulation validation was performed for the hover, low-speed, and sideward flight modes, with consideration of the in-ground rotor effect. Several deficiencies of the mathematical model and the simulation systems were identified in the course of the simulation validation project, and some were corrected. It is noted that NASA's Vertical Motion Simulator used in the program is an excellent tool for tilt-rotor and rotorcraft design, development, and pilot training.

Ferguson, S. W.; Hanson, G. D.; Churchill, G. B.

1984-01-01

181

Evaluation of a load cell model for dynamic calibration of the rotor systems research aircraft  

NASA Technical Reports Server (NTRS)

The Rotor Systems Research Aircraft uses load cells to isolate the rotor/transmission system from the fuselage. An analytical model of the relationship between applied rotor loads and the resulting load cell measurements is derived by applying a force-and-moment balance to the isolated rotor/transmission system. The model is then used to estimate the applied loads from measured load cell data, as obtained from a ground-based shake test. Using nominal design values for the parameters, the estimation errors, for the case of lateral forcing, were shown to be on the order of the sensor measurement noise in all but the roll axis. An unmodeled external load appears to be the source of the error in this axis.

Duval, R. W.; Bahrami, H.; Wellman, B.

1985-01-01

182

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

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

183

NARVAL North - Remote Sensing of Postfrontal Convective Clouds and Precipitation over the North Atlantic with the Research Aircraft HALO  

NASA Astrophysics Data System (ADS)

The new German research aircraft HALO (High Altitude and Long Range Research Aircraft) became recently available for measurement flights in atmospheric research. It's capacity of measuring from a high altitude vertical profiles of all components of atmospheric water - like vapor, liquid and ice, in both cloud and precipitation forms, as well as the aerosol particles upon which cloud droplets form - makes it a unique research platform. The aircraft, equipped with advanced radiometers, radar and lidar technology, the HALO Microwave Package (HAMP), is an initiative by German climate and environmental research institutions and is operated by the German Aerospace Center (DLR). One of the first major missions to exploit the capabilities of HALO was conducted for the NARVAL project (Next-generation Aircraft Remote-Sensing for Validation Studies) during January 2014. After studying subtropical clouds one month before in the first NARVAL phase, the interest of NARVAL North focused on the study of cold air convection and precipitation in the form of rain and snow. Based at Keflavik airport (Iceland), several flights were conducted to examine the specific small-scale precipitation structures behind the backsides of cold fronts over the North Atlantic. This should help to narrow the gap in the understanding of substantial differences between satellite observations and model calculations in such situations. First data analysis of these measurements indicate promising results. The poster will describe the HALO instrument packages as well as the collected observations during the campaign and will present preliminary scientific findings.

Klepp, Christian; Ament, Felix; Bakan, Stephan; Crewell, Susanne; Hagen, Martin; Hirsch, Lutz; Jansen, Friedhelm; Konow, Heike; Mech, Mario; Pfeilsticker, Klaus; Schäfler, Andreas; Stevens, Bjorn

2014-05-01

184

Antecedents and analogues - Experimental aircraft  

NASA Technical Reports Server (NTRS)

The paper reviews the development of experimental aircraft from 1953 to the present. Consideration is given to the X-series experimental aircraft, to X-15 (the first aerospace plane), to the transition of experimental aircraft to high-speed flight, to XB-70 research, to lifting body research aircraft, and to current high-speed flight research.

Smith, R. H.

1978-01-01

185

Design and Development of an Acoustic Test Section for the ARA (Aircraft Research Association) Transonic Wind Tunnel.  

National Technical Information Service (NTIS)

The structural, aerodynamic and acoustic design of a lined test section necessary to produce a sufficiently reflection-free environment for noise tests in the Aircraft Research Association (ARA) tunnel at Mach numbers up to 0.85 are described. The aerodyn...

M. E. Wood D. A. Newman

1988-01-01

186

Static aeroelastic analysis of a three-dimensional generic wing  

NASA Technical Reports Server (NTRS)

A continuation of research on the static aeroelastic analysis of a generic wing configuration is presented. Results of the study of the asymmetric oblique wing model developed by Rockwell International, in conjunction with the NASA Oblique Wing Research Aircraft Program, are reported. The capability to perform static aeroelastic analyses of an oblique wing at arbitrary skew positions is demonstrated by applying the MSC/NASTRAN static analysis scheme modified by the aerodynamic influence coefficient matrix created by the NASA Ames aerodynamic panel codes. The oblique wing is studied at two skew angles, and in particular, the capability to calculate 3-D thickness effects on the aerodynamic properties of the wing is investigated. The ability to model asymmetric wings in both subsonic and supersonic Mach numbers is shown. The aerodynamic influence coefficient matrix computed by the external programs is inserted in MSC/NASTRAN static aeroelasticity analysis run stream to compute the aeroelastic deformation and internal forces. Various aerodynamic coefficients of the oblique wing were computed for two Mach numbers, 0.7 and 1.4, and the angle of attach -5 through 15 deg.

Green, John A.; Lee, IN; Miura, Hirokazu

1990-01-01

187

Research In Nonlinear Flight Control for Tiltrotor Aircraft Operating in the Terminal Area  

NASA Technical Reports Server (NTRS)

The research during the first year of the effort focused on the implementation of the recently developed combination of neural net work adaptive control and feedback linearization. At the core of this research is the comprehensive simulation code Generic Tiltrotor Simulator (GTRS) of the XV-15 tilt rotor aircraft. For this research the GTRS code has been ported to a Fortran environment for use on PC. The emphasis of the research is on terminal area approach procedures, including conversion from aircraft to helicopter configuration. This report focuses on the longitudinal control which is the more challenging case for augmentation. Therefore, an attitude command attitude hold (ACAH) control augmentation is considered which is typically used for the pitch channel during approach procedures. To evaluate the performance of the neural network adaptive control architecture it was necessary to develop a set of low order pilot models capable of performing such tasks as, follow desired altitude profiles, follow desired speed profiles, operate on both sides of powercurve, convert, including flaps as well as mastangle changes, operate with different stability and control augmentation system (SCAS) modes. The pilot models are divided in two sets, one for the backside of the powercurve and one for the frontside. These two sets are linearly blended with speed. The mastangle is also scheduled with speed. Different aspects of the proposed architecture for the neural network (NNW) augmented model inversion were also demonstrated. The demonstration involved implementation of a NNW architecture using linearized models from GTRS, including rotor states, to represent the XV-15 at various operating points. The dynamics used for the model inversion were based on the XV-15 operating at 30 Kts, with residualized rotor dynamics, and not including cross coupling between translational and rotational states. The neural network demonstrated ACAH control under various circumstances. Future efforts will include the implementation into the Fortran environment of GTRS, including pilot modeling and NNW augmentation for the lateral channels. These efforts should lead to the development of architectures that will provide for fully automated approach, using similar strategies.

Calise, A. J.; Rysdyk, R.

1996-01-01

188

Development of an Unmanned Aircraft System and Cyberinfrastructure for Environmental Science Research  

NASA Astrophysics Data System (ADS)

There is a fundamental need to improve capacities for monitoring environmental change using remote sensing technologies. Recently, researchers have begun using Unmanned Aerial Vehicles (UAVs) to expand and improve upon remote sensing capabilities. Limitations to most non-military and relatively small-scale Unmanned Aircraft Systems (UASs) include a need to develop more reliable communications between ground and aircraft, tools to optimize flight control, real time data processing, and visually ascertaining the quantity of data collected while in air. Here we present a prototype software system that has enhanced communication between ground and the vehicle, can synthesize near real time data acquired from sensors on board, can log operation data during flights, and can visually demonstrate the amount and quality of data for a sampling area. This software has the capacity to greatly improve the utilization of UAS in the environmental sciences. The software system is being designed for use on a paraglider UAV that has a suite of sensors suitable for characterizing the footprints of eddy covariance towers situated in the Chihuahuan Desert and in the Arctic. Sensors on board relay operational flight data (airspeed, ground speed, latitude, longitude, pitch, yaw, roll, acceleration, and video) as well as a suite of customized sensors. Additional sensors can be added to an on board laptop or a CR1000 data logger thereby allowing data from these sensors to be visualized in the prototype software. This poster will describe the development, use and customization of our UAS and multimedia will be available during AGU to illustrate the system in use. UAV on workbench in the lab UAV in flight

Brady, J. J.; Tweedie, C. E.; Escapita, I. J.

2009-12-01

189

Identification of linearized equations of motion for the fixed wing configuration of the rotor systems research aircraft  

NASA Technical Reports Server (NTRS)

The purpose of this report is to establish linear, decoupled models of rigid body motion for the fixed wing configuration of the Rotor Systems Research Aircraft (RSRA). Longitudinal and lateral control surface fixed linear models were created from aircraft time histories using current system identification techniques. Models were obtained from computer simulation at 160 KCAS and 200 KCAS, and from flight data at 160 KCAS. Comparisons were performed to examine modeling accuracy, variation of dynamics with airspeed and correlation of simulation and flight data results. The results showed that the longitudinal and lateral linear models accurately predicted RSRA dynamics. The flight data results showed that no significant handling qualities problems were present in the RSRA fixed wing aircraft at the flight speed tested.

Balough, D. L.; Sandlin, D. R.

1986-01-01

190

Science requirements and feasibility/design studies of a very-high-altitude aircraft for atmospheric research  

NASA Technical Reports Server (NTRS)

The advantages and shortcomings of currently available aircraft for use in very high altitude missions to study such problems as polar ozone or stratosphere-troposphere exchange pose the question of whether to develop advanced aircraft for atmospheric research. To answer this question, NASA conducted a workshop to determine science needs and feasibility/design studies to assess whether and how those needs could be met. It was determined that there was a need for an aircraft that could cruise at an altitude of 30 km with a range of 6,000 miles with vertical profiling down to 10 km and back at remote points and carry a payload of 3,000 lbs.

Russell, Philip B.; Lux, David P.; Reed, R. Dale; Loewenstein, Max; Wegener, Steven

1991-01-01

191

The use of the National Research Council of Canada's Falcon 20 research aircraft as a terrestrial analogue space environment (TASE) for space surgery research: Challenges and suggested solutions  

NASA Astrophysics Data System (ADS)

Emergency surgery will be needed to prevent death if humans are used to explore beyond low earth's orbit. Laparoscopic surgery (LS) is envisioned as a less invasive option for space, but will induce further stresses and complicate logistical requirements. Thus, further study into the technology and physiology of LS in weightlessness is required. We recently utilized the National Research Council of Canada's Flight Research Laboratory's Falcon 20 aircraft as a terrestrial analogue space environment (TASE) for space surgery research. The Falcon 20 had never been used for this purpose nor had the involved teams collaborated previously. There were many process challenges including the lack of antecedent surgical studies on this aircraft, a requirement for multiple disciplines who were unfamiliar and geographically distant from each other, flight performance limitations with the Falcon 20, complex animal care requirements, requirements for prototypical in-flight life-support surgical suites, financial limitations, and a need to use non-flight hardened technologies. Stepwise suggested solutions to these challenges are outlined as guidelines for future investigators intending similar research. Overall, the Falcon 20 TASE, backed by the flight resources, especially the design and fabrication capabilities of the NRC-FRL, provide investigators with a versatile and responsive opportunity to pursue research into advanced medical techniques that will be needed to save lives during space exploration.

Kirkpatrick, A. W.; Keaney, M. A.; Bentz, K.; Groleau, M.; Tyssen, M.; Keyte, J.; Ball, C. G.; Campbell, M. R.; Grenon, S. M.; McBeth, P.; Broderick, T. J.

2010-03-01

192

Users Guide for NASA Lewis Research Center DC-9 Reduced-Gravity Aircraft Program  

NASA Technical Reports Server (NTRS)

The document provides guidelines and information for users of the DC-9 Reduced-Gravity Aircraft Program. It describes the facilities, requirements for test personnel, equipment design and installation, mission preparation, and in-flight procedures. Those who have used the KC-135 reduced-gravity aircraft will recognize that many of the procedures and guidelines are the same.

Neumann, Eric S.; Withrow, James P.; Yaniec, John S.

1996-01-01

193

Research on coherent fault diagnosis of aircraft based on probability causal network  

Microsoft Academic Search

Nowadays, the Built-in test (BIT) technique is adopted widely in aircraft fault diagnosis and maintenance. However, because of the complicated structure, mass data transmission, and especially propagations of coherent faults in aircraft, it is difficult to localize faults and to guarantee the accuracy and efficiency of BIT fault diagnosis. To reduce the high BIT false alarm rate (FAR), the coherent

Cunbao Ma; Chao Zhang; Wei Zhou; Dong Song

2008-01-01

194

Using Hyperspectral Aircraft Remote Sensing to Support Ecosystems Services Research in New England Lakes and Ponds  

NASA Astrophysics Data System (ADS)

Northeastern lakes and ponds provide important ecosystem services to New England residents and visitors. These include the provisioning of abundant, clean water for consumption, agriculture, and industry as well as cultural services (recreation, aesthetics, and wilderness experiences) which enhance local economies and quality of life. Less understood, but equally important, are the roles that these lakes play in protecting all life through supportive services such as nutrient cycling. Nitrogen and phosphorus have a direct impact on the condition of fresh water lakes. Excesses of these nutrients can lead to eutrophication, toxic cyanobacteria blooms, decreased biodiversity, and loss of ecosystem function leading to a reduction in the availability and delivery of ecosystem services. In this study, we examined how variations in lake nutrient concentrations and phytoplankton pigment concentrations correlated with changes in the potential to provide cultural ecosystem services. Using a NASA Cessna 206 aircraft, hyperspectral data were collected during late summer 2009 from 55 lakes in New Hampshire, Massachusetts, Connecticut, and Rhode Island over a 2 day period. From the spectral data, algorithms were created which estimated concentrations of chlorophyll a, phycocyanin, and colored dissolved organic matter. The remotely sensed estimates were supplemented by in situ chlorophyll a, total nitrogen, total phosphorus and lake color data from 43 lakes sampled by field crews from the New England states. The purpose of this research is to understand how variations in lake nutrient concentrations and phytoplankton pigment concentrations correlate with changes in availability of cultural ecosystem services in the surveyed lakes. This dataset will be combined with information from the EPA National Lake Survey (2007), the EPA New England Lakes and Ponds Survey (2008) and the USGS SPARROW model to explore the association between lake condition and the provisioning of ecosystem services on a regional scale. Under the EPA Ecological Services Research Program (ESRP), this information will provide managers and researchers with a better understanding of links between management decisions affecting nutrient fluxes and impacts on selected ecosystem services.

Keith, D. J.; Milstead, B.; Walker, H.; Worthy, D.; Szykman, J.; Wusk, M.; Kagey, L.; Howell, C.; Snook, H.; Drueke, C.

2010-12-01

195

Hypersonic aerodynamic characteristics of an all-body research aircraft configuration  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted at Mach 6 to determine the hypersonic aerodynamic characteristics of an all-body, delta-planform, hypersonic research aircraft (HYFAC configuration). The aerodynamic characteristics were obtained at Reynolds numbers based on model length of 2.84 million and 10.5 million and over an angle-of-attack range from minus 4 deg to 20 deg. The experimental results show that the HYFAC configuration is longitudinally stable and can be trimmed over the range of test conditions. The configuration had a small degree of directional stability over the angle-of-attack range and positive effective dihedral at angles of attack greater than 2 deg. Addition of canards caused a decrease in longitudinal stability and an increase in directional stability. Oil-flow studies revealed extensive areas of separated and vortex flow on the fuselage lee surface. A limited comparison of wind-tunnel data with several hypersonic approximations indicated that, except for the directional stability, the tangent-cone method gave adequate agreement at control settings between 5 deg and minus 5 deg and positive lift coefficient. A limited comparison indicated that the HYFAC configuration had greater longitudinal stability than an elliptical-cross-section configuration, but a lower maximum lift-drag ratio.

Clark, L. E.

1973-01-01

196

Estimation of dynamic rotor loads for the rotor systems research aircraft: Methodology development and validation  

NASA Technical Reports Server (NTRS)

The Rotor Systems Research Aircraft uses load cells to isolate the rotor/transmission systm from the fuselage. A mathematical model relating applied rotor loads and inertial loads of the rotor/transmission system to the load cell response is required to allow the load cells to be used to estimate rotor loads from flight data. Such a model is derived analytically by applying a force and moment balance to the isolated rotor/transmission system. The model is tested by comparing its estimated values of applied rotor loads with measured values obtained from a ground based shake test. Discrepancies in the comparison are used to isolate sources of unmodeled external loads. Once the structure of the mathematical model has been validated by comparison with experimental data, the parameters must be identified. Since the parameters may vary with flight condition it is desirable to identify the parameters directly from the flight data. A Maximum Likelihood identification algorithm is derived for this purpose and tested using a computer simulation of load cell data. The identification is found to converge within 10 samples. The rapid convergence facilitates tracking of time varying parameters of the load cell model in flight.

Duval, R. W.; Bahrami, M.

1985-01-01

197

Preliminary design of propulsion system for V/STOL research and technology aircraft  

NASA Technical Reports Server (NTRS)

The V/STOL Research and Technology Aircraft (RTA)propulsion system design effort is limited to components of the lift/cruise engines, turboshaft engine modifications, lift fan assembly, and propulsion system performance generation. The uninstalled total net thrust with all engines and fans operating at intermediate power was 37,114 pounds. Uninstalled system total net thrust was 27,102 pounds when one lift/cruise is inoperative. Components have lives above the 500 hours of the RTA duty cycle. The L/C engine used in a fixed nacelle has the cross shaft forward of the reduction gear whereas the cross shaft is aft of the reduction gear in a tilt nacelle L/C engine. The lift/cruise gearbox contains components and technologies from other DDA engines. The rotor has a 62-inch diameter and contains 22 composite blades that have a hub/tip ratio of 0.454. The blade pitch change mechanism contains hydraulic and mechanical redundancy. The lift fan assembly is completely self-contained including oil cooling in 10 exit vanes.

1977-01-01

198

HAMP - the microwave package on the High Altitude and LOng range research aircraft HALO  

NASA Astrophysics Data System (ADS)

An advanced package of microwave remote sensing instrumentation has been developed for the operation on the new German High Altitude LOng range research aircraft (HALO). The HALO Microwave Package, HAMP, consists of two nadir looking instruments: a cloud radar at 36 GHz and a suite of passive microwave radiometers with 26 frequencies in different bands between 22.24 and 183.31 ± 12.5 GHz. We present a description of HAMP's instrumentation together with an illustration of its potential. To demonstrate this potential synthetic measurements for the implemented passive microwave frequencies and the cloud radar based on cloud resolving and radiative transfer model calculations were performed. These illustrate the advantage of HAMP's chosen frequency coverage, which allows for improved detection of hydrometeors both via the emission and scattering of radiation. Regression algorithms compare HAMP retrieval with standard satellite instruments from polar orbiters and show its advantages particularly for the lower atmosphere with a reduced root mean square error by 5 and 15% for temperature and humidity, respectively. HAMP's main advantage is the high spatial resolution of about 1 km which is illustrated by first measurements from test flights. Together these qualities make it an exciting tool for gaining better understanding of cloud processes, testing retrieval algorithms, defining future satellite instrument specifications, and validating platforms after they have been placed in orbit.

Mech, M.; Orlandi, E.; Crewell, S.; Ament, F.; Hirsch, L.; Hagen, M.; Peters, G.; Stevens, B.

2014-05-01

199

Aerodynamic characteristics of a 1/6-scale model of the rotor systems research aircraft with the rotors removed. [wind tunnel tests of aircraft models  

NASA Technical Reports Server (NTRS)

A wind-tunnel investigation was conducted to refine the aerodynamic characteristics of the rotor systems research aircraft. For the investigation, a 1/6-scale model without a main rotor or a tail rotor was used. The model provided the capability for testing different engine nacelle sizes, engine pylon fairings, and tail configurations. The engine thrust effects were modeled by small engine simulators (fans). Data were obtained primarily over an angle-of-attack range from -13 deg to 13 deg at several values of sideslip. Stability characteristics and control effectiveness were investigated. The model with the scaled engine nacelles and the combination T-tail and lower horizontal tail displayed longitudinal and lateral-directional stability. Results show that by reducing the horizontal or vertical-tail span the longitudinal stability is decreased. Reducing the engine nacelle size increases the static stability of the model. Effective dihedral is essentially zero at 0 deg angle of attack and 0 deg wing incidence.

Mineck, R. E.; Freeman, C. R.; Hassell, J. L., Jr.

1976-01-01

200

Sweeping Forward: Developing and Flight Testing the Grumman X-29 Forward Swept Wing Research Aircraft.  

National Technical Information Service (NTIS)

Aircraft design, more than many other disciplines, exemplifies the phrase form follows function. The laws of physics demand it. Aeronautical designers have always reached forward, stretching capabilities as far as the constraints of gravity and the limits...

F. A. Johnsen

2013-01-01

201

Simulator Model Specification for the Augmentor Wing Jet STOL Research Aircraft.  

National Technical Information Service (NTIS)

The configuration and simulation studies of a C-8A (De Havilland Buffalo) aircraft are described. The modifications to STOL configuration consisted of augmentor-wing jet flaps, blown and drooped ailerons, and leading edge slats. The total simulator model ...

P. C. Rumsey, R. E. Spitzer

1971-01-01

202

Assessing Regional Scale Fluxes of Mass, Momentum, and Energy with Small Environmental Research Aircraft  

NASA Astrophysics Data System (ADS)

Natural ecosystems are rarely structurally or functionally homogeneous. This is true for the complex coastal regions of Magdalena Bay, Baja California Sur, Mexico, and the Barrow Peninsula on the Arctic Coastal Plain of Alaska. The coastal region of Magdalena Bay is comprised of the Pacific coastal ocean, eutrophic lagoon, mangroves, and desert ecosystems all adjacent and within a few kilometers, while the Barrow Peninsula is a mosaic of small ponds, thaw lakes, different aged vegetated thaw-lake basins ( VDTLBs ) and interstitial tundra which have been dynamically formed by both short- and long-term processes. We used a combination of tower- and small environmental research aircraft (SERA)-based eddy covariance measurements to characterize the spatial and temporal patterns of CO2, latent, and sensible heat fluxes along with MODIS NDVI, and land surface information, to scale the SERA-based CO2 fluxes up to the regional scale. In the first part of this research, the spatial variability in ecosystem fluxes from the Pacific coastal ocean, eutrophic lagoon, mangroves, and desert areas of northern Magdalena Bay were studied. SERA-derived average midday CO2 fluxes from the desert showed a slight uptake of -1.32 mumol CO2 m-2 s-1, the coastal ocean also showed uptake of -3.48 mumol CO2 m-2 s -1, and the lagoon mangroves showed the highest uptake of -8.11 mumol CO2 m-2 s-1. Additional simultaneous measurements of NDVI allowed simple linear modeling of CO2 flux as a function of NDVI for the mangroves of the Magdalena Bay region. In the second part of this research, the spatial variability of ecosystem fluxes across the 1802 km2 Barrow Peninsula region was studied. During typical 2006 summer conditions, the midday hourly CO2 flux over the region was -2.04 x 105 kgCO2 hr-1. The CO2 fluxes among the interstitial tundra, Ancient and Old VDTLBs, as well as between the Medium and Young VDTLBs were not significantly different. Combined, the interstitial tundra and Old and Ancient VDTLBs, represent ˜67% of the Barrow Peninsula surface area, accounting for ˜59% of the regional flux signal. Though the Medium and Young VDTLBs represent ˜11% of the surface area, they account for a large portion, ˜35%, of the total regional flux. The remaining ˜22% of the surface area are lakes and contributed the remaining ˜6% of the total regional flux. Previous studies treated vegetated areas of the region as a single surface type with measurements from a few study sites; doing so could underestimate the regional flux by ˜22%. The San Diego State University Sky Arrow 650TCN Environmental Research Aircraft proved to be an effective tool in characterizing land-atmosphere fluxes of energy, CO2 and water across heterogeneous landscapes at the scale of 1 km, and was capable of discriminating fluxes from the various ecosystem and land surface types a few kilometers distant. Here, we demonstrate that SERA-based approaches have the ability to cover large spatial scales while measuring the turbulent fluxes across a number of surfaces and combined with ground- and satellite-based measurements provide a valuable tool for both scaling and validation of regional-scale fluxes.

Zulueta, Rommel Callejo

203

The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission: design, execution, and first results  

Microsoft Academic Search

The NASA Arctic Research of the Composi- tion of the Troposphere from Aircraft and Satellites (ARC- TAS) mission was conducted in two 3-week deployments based in Alaska (April 2008) and western Canada (June-July 2008). Its goal was to better understand the factors driving current changes in Arctic atmospheric composition and cli- mate, including (1) influx of mid-latitude pollution, (2) bo-

D. J. Jacob; J. H. Crawford; H. Maring; A. D. Clarke; J. E. Dibb; L. K. Emmons; R. A. Ferrare; C. A. Hostetler; P. B. Russell; H. B. Singh; A. M. Thompson; G. E. Shaw; E. McCauley; J. R. Pederson; J. A. Fisher

2010-01-01

204

The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission: design, execution, and first results  

Microsoft Academic Search

The NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was conducted in two 3-week deployments based in Alaska (April 2008) and western Canada (June-July 2008). Its goal was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1) influx of mid-latitude pollution, (2) boreal forest fires, (3)

D. J. Jacob; J. H. Crawford; H. Maring; A. D. Clarke; J. E. Dibb; L. K. Emmons; R. A. Ferrare; C. A. Hostetler; P. B. Russell; H. B. Singh; A. M. Thompson; G. E. Shaw; E. McCauley; J. R. Pederson; J. A. Fisher

2010-01-01

205

Application of piloted simulation to high-angle-of-attack flight-dynamics research for fighter aircraft  

NASA Technical Reports Server (NTRS)

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, is reviewed. 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.

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

1992-01-01

206

A Remotely Piloted Aircraft (RPA) as a Measurement Tool for Wind-Energy Research  

NASA Astrophysics Data System (ADS)

In wind energy meteorology, RPA have the clear advantage compared to manned aircraft that they allow to fly very close to the ground and even in between individual wind turbines in a wind farm. Compared to meteorological towers and lidar systems, the advantage is the flexibility of the system, which makes it possible to measure at the desired site on short notice and not only in main wind direction. At the Center of Applied Geoscience at the University of Tübingen, the research RPA MASC (Multi-purpose Airborne Sensor Carrier) was developed. RPA of type MASC have a wingspan of about 3 m and a maximum take-off weight of 7.5 kg, including payload. The standard meteorological payload includes instruments for temperature, humidity, barometric pressure and wind measurement. It is possible to resolve turbulence fluctuations of wind and temperature up to 20 Hz. The autopilot ROCS (Research Onboard Computer System), which is developed at the Institute of Flight Mechanics and Control, University of Stuttgart, makes it possible to automatically follow predefined waypoints at constant altitude and airspeed. At a cruising speed of 24 m/s and a battery life of approx. one hour, a range of 80 km is feasible. The project 'Lidar Complex', funded by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, is part of the research network 'WindForS', based in Southern Germany. The goal of the project is to establish lidar technology for wind energy plant site evaluation in complex terrain. Additional goals are the comparison of different measurement techniques and the validation of wind-field models in not IEC 61400 conform terrain. It is planned to design a turbulent wind-field generator, fed by real measurement data, which can be used to analyse WEC behaviour. Two test sites were defined for the 'Lidar Complex' project, one in IEC-conform terrain about 15 km from the Baltic Sea, the other in the Swabian Alb, only 2 km downstream of a 100 m steep escarpment. At both sites, flight measurements were performed in 2013 with the RPA MASC. The data that was collected allows to investigate the influence of thermal stability of the atmosphere at the test site and turbulence intensity around individual wind energy converters (WECs). Several measurement flights were done to investigate the wake structure downstream a running WEC. Preliminary results will be presented as well as an outlook for future research with the instrument.

Wildmann, Norman; Bange, Jens

2014-05-01

207

Small transport aircraft technology  

NASA Technical Reports Server (NTRS)

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.

Williams, L. J.

1983-01-01

208

Transonic Wind-Tunnel Test Of An Oblique Wing  

NASA Technical Reports Server (NTRS)

Report describes transonic wind-tunnel tests of oblique, pivotable wing fitted to 0.087-scale model of F-8 airplane. Purpose of tests to study performance and stability characteristics. Conducted to determine whether placement of pivot at higher position above fuselage than previously results in less side force and yawing moment than observed in previous tests at low speeds.

Kennelly, R. A.; Strong, J. M.; Carmichael, R. L.; Kroo, I. M.

1992-01-01

209

A Preliminary Study of V/STOL Transport Aircraft and Bibliography of NASA Research in the VTOL-STOL Field  

NASA Technical Reports Server (NTRS)

This group of papers was prepared by the staff of the Langley Research Center to assist in planning for future commercial air-transport facilities in the New York metropolitan area. Areas of particular interest were predictions regarding the types of V/STOL aircraft that are likely to be developed for various commercial transport applications, estimates of the performance and probable operating procedures for such aircraft, and the approximate dates these aircraft could be available for use. Although the NASA has made no comprehensive studies of this type, the extensive research program in the VTOL-STOL field during the last 10 years appeared to provide a source for some of the desired information . The five papers included herein were therefore prepared to summarize pertinent available material in a form suitable for the intended use. In several instances, new studies and analysis were required to provide the necessary information, but because of a time deadline, many of the significant points received only a cursory examination. For example, much of the quantitative data used in the papers for making generalized comparisons was obtained by approximate methods and is not considered appropriate for use in applications where precise estimates are required. It should be recognized, then, that the treatment of the V/STOL transport provided by this group of papers is necessarily of a preliminary nature.

1961-01-01

210

Structural dynamics research in a full-scale transport aircraft crash test  

NASA Technical Reports Server (NTRS)

A remotely piloted air-to-ground crash test of a full-scale transport aircraft was conducted for the first time for two purposes: (1) to demonstrate performance of an antimisting fuel additive in suppressing fire in a crash environment, and (2) to obtain structural dynamics data under crash conditions for comparison with analytical predictions. The test, called the Controlled Impact Demonstration (CID), was sponsored by FAA and NASA with cooperation of industry, the Department of Defense, and the British and French governments. The test aircraft was a Boeing 720 jet transport. The aircraft impacted a dry lakebed at Edwards Air Force Base, CA. The purpose of this paper is to discuss the structural aspects of the CID. The fuselage section tests and the CID itself are described. Structural response data from these tests are presented and discussed. Nonlinear analytical modeling efforts are described, and comparisons between analytical results and experimental results are presented.

Mccomb, H. G., Jr.; Hayduk, R. J.; Thomson, R. G.

1986-01-01

211

Trajectory module of the NASA Ames Research Center aircraft synthesis program ACSYNT  

NASA Technical Reports Server (NTRS)

A program was developed to calculate trajectories for both military and commercial aircraft for use in the aircraft synthesis program, ACSYNT. The function of the trajectory module was to calculate the changes in the vehicle's flight conditions and weight, as fuel is consumed, during the flying of one or more missions. The trajectory calculations started with a takeoff, followed by up to 12 phases chosen from among the following: climb, cruise, acceleration, combat, loiter, descent, and paths. In addition, a balanced field length was computed. The emphasis was on relatively simple formulations and analytic expressions suitable for rapid computation since a prescribed trajectory had to be calculated many times in the process of converging an aircraft design, or finding an optimum configuration. The trajectory module consists of about 2500 cards and operational on a CDC 7600 computer.

Tauber, M. E.; Paterson, J. A.

1978-01-01

212

Linear and nonlinear interpretation of the direct strike lightning response of the NASA F106B thunderstorm research aircraft  

NASA Technical Reports Server (NTRS)

The objective of the work reported here is to develop a methodology by which electromagnetic measurements of inflight lightning strike data can be understood and extended to other aircraft. A linear and time invariant approach based on a combination of Fourier transform and three dimensional finite difference techniques is demonstrated. This approach can obtain the lightning channel current in the absence of the aircraft for given channel characteristic impedance and resistive loading. The model is applied to several measurements from the NASA F106B lightning research program. A non-linear three dimensional finite difference code has also been developed to study the response of the F106B to a lightning leader attachment. This model includes three species air chemistry and fluid continuity equations and can incorporate an experimentally based streamer formulation. Calculated responses are presented for various attachment locations and leader parameters. The results are compared qualitatively with measured inflight data.

Rudolph, T. H.; Perala, R. A.

1983-01-01

213

An analytical investigation of acquisition techniques and system integration studies for a radar aircraft guidance research facility, phase 2  

NASA Technical Reports Server (NTRS)

A review of user requirements and updated instrumentation plans are presented for the aircraft tracking and guidance facility at NASA Wallops Station. User demand has increased as a result of new flight research programs; however, basic requirements remain the same as originally reported. Instrumentation plans remain essentially the same but with plans for up- and down-link telemetry more firm. With slippages in the laser acquisition schedule, added importance is placed on the FPS-16 radar as the primary tracking device until the laser is available. Limited simulation studies of a particular Kalman-type filter are also presented. These studies simulated the use of the filter in a helicopter guidance loop in a real-time mode. Disadvantages and limitations of this mode of operation are pointed out. Laser eyesafety calculations show that laser tracking of aircraft is readily feasible from the eyesafety viewpoint.

Thompson, W. S.; Ruedger, W. H.

1973-01-01

214

RSRA aircraft in flight  

NASA Technical Reports Server (NTRS)

A Rotor Systems Research Aircraft (RSRA) is seen here on a flight test at the Dryden Flight Research Center, Edwards, California, in spring of 1984. The tests at Dryden were to familiarize pilots and researchers with ground-handling and takeoff flight characteristics, as well as to acquire in-flight data in the aircraft configuration, with the main rotor removed. The RSRA was a unique pure research aircraft developed to fill the void between design analysis, wind tunnel testing, and flight results of rotor aircraft. The joint NASA/Army project began in December of 1970, with the first of two aircraft arriving from Sikorsky on February 11, 1979. The aircraft was designed to investigate the concepts involved with stopping the main rotor in flight, with the large blades then providing aerodynamic lift assistance to the stubby conventional wings extending from the lower fuselage. This concept gave the aircraft the vertical flight stability of a helicopter, and the horizontal cruise capability of a conventional aircraft. Tests were successful and lead to later rotor research conducted at NASA's Ames Research Center. One of the two RSRA aircraft was later modified to the X-Wing and received limited testing at Dryden before the program was terminated in 1988.

1984-01-01

215

Solus: an autonomous aircraft for flight control and trajectory planning research  

Microsoft Academic Search

The University of Michigan has developed a fixed-wing model aircraft (Solus) with an embedded control system to develop and demonstrate UAV technology. The analytical objective of this project is the development of intelligent flight control and trajectory planning techniques, focusing on automated fault detection and recovery. Our experimental objective is to implement and evaluate these techniques on Solus for a

Ella M. Atkins; R. H. Miller; T. Van Pelt; Keith D. Shaw; W. B. Ribbens; Peter D. Washabaugh; Dennis S. Bernstein

1998-01-01

216

A NASA/University/Industry Consortium for Research on Aircraft Ice Protection  

NASA Technical Reports Server (NTRS)

From 1982 through 1987, an unique consortium was functioning which involved government (NASA), academia (Wichita State Univ.) and twelve industries. The purpose was the development of a better ice protection systems for aircraft. The circumstances which brought about this activity are described, the formation and operation recounted, and the effectiveness of the ventue evaluated.

Zumwalt, Glen W.

1989-01-01

217

Experimental research on photocatalytic oxidation air purification technology applied to aircraft cabins  

Microsoft Academic Search

The experiment presented in this report was performed in a simulated aircraft cabin to evaluate the air cleaning effects of two air purification devices that used photocatalytic oxidation (PCO) technology. Objective physical, chemical and physiological measurements and subjective human assessments were used for the evaluation. Comparisons were made between conditions with and without the PCO units installed in the re-circulated

Yuexia Sun; Lei Fang; David P. Wyon; Armin Wisthaler; Love Lagercrantz; Peter Strøm-Tejsen

2008-01-01

218

Real-time application of advanced three-dimensional graphic techniques for research aircraft simulation  

NASA Technical Reports Server (NTRS)

Visual aids are valuable assets to engineers for design, demonstration, and evaluation. Discussed here are a variety of advanced three-dimensional graphic techniques used to enhance the displays of test aircraft dynamics. The new software's capabilities are examined and possible future uses are considered.

Davis, Steven B.

1990-01-01

219

RSRA aircraft on ramp  

NASA Technical Reports Server (NTRS)

A Rotor Systems Research Aircraft (RSRA) is seen here on the ramp at the Dryden Flight Research Center, Edwards, California, in spring of 1984. The aircraft underwent tests at Dryden to familiarize pilots and researchers with ground-handling and takeoff flight characteristics, as well as to acquire in-flight data in the aircraft configuration, with the main rotor removed. The test aircraft had a basic helicopter fuselage with the wings and lower horizontal all-flying stabilizer installed. Two auxiliary power plants were mounted on either side of the fuselage. These GE TF-34's were used to offset drag effects when rotor systems were being tested with the aircraft in compound configuration, and to provide thrust for the airplane configuration. The RSRA was a unique pure research aircraft developed to fill the void between design analysis, wind tunnel testing, and flight results of rotor aircraft. The joint NASA/Army project began in December of 1970, with the first of two aircraft arriving from Sikorsky on February 11, 1979. The aircraft was designed to investigate the concepts involved with stopping the main rotor in flight, with the large blades then providing aerodynamic lift assistance to the stubby conventional wings extending from the lower fuselage. This concept gave the aircraft the vertical flight stability of a helicopter, and the horizontal cruise capability of a conventional aircraft. Tests were successful and lead to later rotor research conducted at NASA's Ames Research Center. One of the two RSRA aircraft was later modified to the X-Wing and received limited testing at Dryden before the program was terminated in 1988.

1984-01-01

220

V/STOL tilt rotor study. Volume 5: A mathematical model for real time flight simulation of the Bell model 301 tilt rotor research aircraft  

NASA Technical Reports Server (NTRS)

A mathematical model for real-time flight simulation of a tilt rotor research aircraft was developed. The mathematical model was used to support the aircraft design, pilot training, and proof-of-concept aspects of the development program. The structure of the mathematical model is indicated by a block diagram. The mathematical model differs from that for a conventional fixed wing aircraft principally in the added requirement to represent the dynamics and aerodynamics of the rotors, the interaction of the rotor wake with the airframe, and the rotor control and drive systems. The constraints imposed on the mathematical model are defined.

Harendra, P. B.; Joglekar, M. J.; Gaffey, T. M.; Marr, R. L.

1973-01-01

221

Effects of Aircraft Noise: Research Update on Selected Topics. A Synthesis of Airport Practice. Airport Cooperative Research Program Synthesis 9.  

National Technical Information Service (NTIS)

In the years since Aviation Noise Effects(FAA Report No. FAA-EE-85-2) was published in 1985, much has changed in the aviation world. Quieter jets, increased air travel, new breeds of aircraft types, increased awareness of proper land-use planning, and mit...

V. Mestre

2008-01-01

222

Modeling of the Mode S tracking system in support of aircraft safety research  

NASA Technical Reports Server (NTRS)

This report collects, documents, and models data relating the expected accuracies of tracking variables to be obtained from the FAA's Mode S Secondary Surveillance Radar system. The data include measured range and azimuth to the tracked aircraft plus the encoded altitude transmitted via the Mode S data link. A brief summary is made of the Mode S system status and its potential applications for aircraft safety improvement including accident analysis. FAA flight test results are presented demonstrating Mode S range and azimuth accuracy and error characteristics and comparing Mode S to the current ATCRBS radar tracking system. Data are also presented that describe the expected accuracy and error characteristics of encoded altitude. These data are used to formulate mathematical error models of the Mode S variables and encoded altitude. A brief analytical assessment is made of the real-time tracking accuracy available from using Mode S and how it could be improved with down-linked velocity.

Sorensen, J. A.; Goka, T.

1982-01-01

223

Government financial support for civil aircraft research, technology and development in four European countries and the United States  

NASA Technical Reports Server (NTRS)

Data on the levels of government financial support for civil aircraft airframe and engine (CAAE) research and technology (R&T) in the United States and Europe (United Kingdom, West Germany, France and The Netherlands) and means of comparing these levels are provided. Data are presented for the years 1974-1977. European R&T expenditure data were obtained through visits to each of the four European countries, to the Washington office of the European Communities, and by a search of applicable literature. CAAE R&T expenditure data for the United States were obtained from NASA and Federal Aviation Administration (FAA).

Chandler, B.; Golaszewski, R.; Patten, C.; Rudman, B.; Scott, R.

1980-01-01

224

Flight control systems research. [optimization of F-8 aircraft control system  

NASA Technical Reports Server (NTRS)

Theoretical development is reported for the parameter optimization design technique needed for digital flight control system design. The results of an example case study applying the optimization technique for continuous systems to an F-8 aircraft feedback control system are presented. The concept of evolving the simplest system configuration that is capable of meeting a specified set of performance requirements is illustrated in this work.

Whitaker, H. P.; Baram, Y.; Cheng, Y.

1973-01-01

225

V/STOL tilt rotor research aircraft. Volume 2: Ship 1 instrumentation  

NASA Technical Reports Server (NTRS)

Information covering sensor cables, sensor installation, and sensor calibration for the XV-15 aircraft number 1 is included. For each junction box (J-box) designation there is a schematic of the J-box disconnect harness instrumentation worksheets which show sensor location, and calibration data sheets for each sensor associated with that J-box. An index of measurement item codes to J-box locations is given in a table. Cross references are given.

1978-01-01

226

The Pilot Land Data System (PLDS) at the Ames Research Center manages aircraft data in collaboration with an ecosystem research project  

NASA Technical Reports Server (NTRS)

The Pilot Land Data System (PLDS) is a data and information system serving NASA-supported investigators in the land science community. The three nodes of the PLDS, one each at the Ames Research Center (ARC), the Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL), cooperate in providing consistent information describing the various data holding in the hardware and software (accessible via network and modem) that provide information about and access to PLDS-held data, which is available for distribution. A major new activity of the PLDS node at the Ames Research Center involves the interaction of the PLDS with an active NASA ecosystem science project, the Oregon Transect Ecosystems Research involves the management of, access to, and distribution of the large volume of widely-varying aircraft data collected by OTTER. The OTTER project, is managed by researchers at the Ames Research Center and Oregon State University. Its principal objective is to estimate major fluxes of carbon, nitrogen, and water of forest ecosystems using an ecosystem process model driven by remote sensing data. Ten researchers at NASA centers and universities are analyzing data for six sites along a temperature-moisture gradient across the western half of central Oregon (called the Oregon Transect). Sensors mounted on six different aircraft have acquired data over the Oregon Transect in support of the OTTER project.

Angelici, Gary; Popovici, Lidia; Skiles, Jay

1991-01-01

227

An inverse modelling approach for frequency response correction of capacitive humidity sensors in ABL research with small unmanned aircraft  

NASA Astrophysics Data System (ADS)

The measurement of water-vapour concentration in the atmosphere is an ongoing challenge in environmental research. Satisfactory solutions are present for ground-based meteorological stations and measurements of mean values. However, advanced research of thermodynamic processes also aloft, above the surface layer and especially in the atmospheric boundary layer (ABL), requires the resolution of small-scale turbulence. Sophisticated optical instruments are used in airborne meteorology with manned aircraft to achieve the necessary fast response measurements in the order of 1 Hz (e.g. LiCor 7500). Since these instruments are too large and heavy for the application on the promising platforms of small remotely piloted aircraft (RPA), a method is presented in this study, that enhances small capacitive humidity sensors to be able to resolve turbulent eddies in the order of 10 m. For this purpose a physical and dynamical model of such a sensor is described and inverted in order to restore original water vapour fluctuations from sensor measurements. Examples of flight measurements show how the method can be used to correct vertical profiles and resolve turbulence spectra up to about 3 Hz.

Wildmann, N.; Kaufmann, F.; Bange, J.

2014-05-01

228

A summary of the forebody high-angle-of-attack aerodynamics research on the F-18 and the X-29A aircraft  

NASA Technical Reports Server (NTRS)

High-angle-of-attack aerodynamic studies have been conducted on both the F18 High Alpha Research Vehicle (HARV) and the X-29A aircraft. Data obtained include on- and off-surface flow visualization and static pressure measurements on the forebody. Comparisons of similar results are made between the two aircraft where possible. The forebody shapes of the two aircraft are different and the X-29A forebody flow is affected by the addition of nose strakes and a flight test noseboom. The forebody flow field of the F-18 HARV is fairly symmetric at zero sideslip and has distinct, well-defined vortices. The X-29A forebody vortices are more diffuse and are sometimes asymmetric at zero sideslip. These asymmetries correlate with observed zero-sideslip aircraft yawing moments.

Bjarke, Lisa J.; Delfrate, John H.; Fisher, David F.

1992-01-01

229

High Temperature Hydrocarbon Fuels Research in an Advanced Aircraft Fuel System Simulator on Fuel AFFB-14-70.  

National Technical Information Service (NTIS)

Hydrocarbon fuels tend to form deposits in the thermal environment associated with high mach number flight. The Advanced Aircraft Fuel System Simulator provides thermal stability data on fuels which are used to determine aircraft fuel system design criter...

R. Bankhead R. P. Bradley W. E. Bucher

1974-01-01

230

Hybrid upper surface blown flap propulsive-lift concept for the Quiet Short-Haul Research Aircraft  

NASA Technical Reports Server (NTRS)

The hybrid upper surface blowing concept consists of wing-mounted turbofan engines with a major portion of the fan exhaust directed over the wing upper surface to provide high levels of propulsive lift, but with a portion of the fan airflow directed over selected portions of the airframe to provide boundary layer control. NASA-sponsored preliminary design studies identified the hybrid upper surface blowing concept as the best propulsive lift concept to be applied to the Quiet Short-Haul Research Aircraft (QSRA) that is planned as a flight facility to conduct flight research at low noise levels, high approach lift coefficients, and steep approaches. Data from NASA in-house and NASA-sponsored small and large-scale wind tunnel tests of various configurations using this concept are presented.

Cochrane, J. A.; Carros, R. J.

1975-01-01

231

Soil analyses and evaluations at the impact dynamics research facility for two full-scale aircraft crash tests  

NASA Technical Reports Server (NTRS)

The aircraft structural crash behavior and occupant survivability for aircraft crashes on a soil surface was studied. The results of placement, compaction, and maintenance of two soil test beds are presented. The crators formed by the aircraft after each test are described.

Cheng, R. Y. K.

1977-01-01

232

Static investigation of the circulation control wing/upper surface blowing concept applied to the quiet short haul research aircraft  

NASA Technical Reports Server (NTRS)

Full scale static investigations were conducted on the Quiet Short Haul Research Aircraft (QSRA) to determine the thrust deflecting capabilities of the circulation control wing/upper surface blowing (CCW/USB) concept. This scheme, which combines favorable characteristics of both the A-6/CCW and QSRA, employs the flow entrainment properties of CCW to pneumatically deflect engine thrust in lieu of the mechanical USB flap system. Results show that the no moving parts blown system produced static thrust deflections in the range of 40 deg to 97 deg (depending on thrust level) with a CCW pressure of 208,900 Pa (30.3 psig). In addition, the ability to vary horizontal forces from thrust to drag while maintaining a constant vertical (or lift) value was demonstrated by varying the blowing pressure. The versatility of the CCW/USB system, if applied to a STOL aircraft, was confirmed, where rapid conversion from a high drag approach mode to a thrust recovering waveoff or takeoff configuration could be achieved by nearly instantaneous blowing pressure variation.

Eppel, J. C.; Shovlin, M. D.; Jaynes, D. N.; Englar, R. J.; Nichols, J. H., Jr.

1982-01-01

233

Preliminary results for an aeromagnetic survey flown over Italy using the HALO (High Altitude and LOng range) research aircraft  

NASA Astrophysics Data System (ADS)

In June 2012 the GEOHALO mission was flown over Italy using the high altitude and long-range German research aircraft HALO (Gulfstream jet - G550). One goal of the mission was to demonstrate the feasibility of using geodetic and geophysical instrumentation on such fast flying aircraft. Several types of data were acquired including gravity, GNSS signals (reflectometry, spectrometry and occultation), laser altimetry and magnetic data. The magnetic data were collected through two independent acquisition chains placed inside under-wing containers. Each chain included a total intensity cesium magnetometer, a three-component fluxgate magnetometer, several temperature censors and a digitizer. Magnetic and temperature data were collected at a 10 Hz sampling rate. Seven parallel profiles, each around 1000 km long, were flown over the Apennine peninsula from north-west to south-east. The flight altitude was about 3500 m and the survey line spacing around 40 km. These long profiles were complemented by four crossing profiles, and a repeated flight line at a higher altitude (approx. 10500 m). The ground speed during the flight was generally around 125 m/s (450 km/h). The output from the first steps of the magnetic data processing will be shown. The measured magnetic data appear to be consistent with the expected signal.

Lesur, V.; Gebler, A.; Schachtschneider, R.

2012-12-01

234

Preliminary results for an aeromagnetic survey flown over Italy using the HALO (High Altitude and LOng range) research aircraft  

NASA Astrophysics Data System (ADS)

In June 2012 the GEOHALO mission was flown over Italy using the high altitude and long-range German research aircraft HALO (Gulfstream jet - G550). One goal of the mission was to demonstrate the feasibility of using geodetic and geophysical instrumentation on such fast flying aircraft. The magnetic data were collected through two independent acquisition chains placed inside under-wing containers. Each chain included a total intensity cesium magnetometer, a three-component fluxgate magnetometer, several temperature censors and a digitizer. Seven parallel profiles, each around 1000 km long, were flown over the Apennine peninsula from north-west to south-east. The flight altitude was about 3500 m and the survey line spacing around 40 km. These long profiles were complemented by four crossing profiles, and a repeated flight line at a higher altitude (approx. 10500 m). The measured magnetic data appear to be consistent with the expected signal. Here we present preliminary results of the data processing. From the calibration maneuvers we have been able to correct the data for most of the plane generated signal. High frequency noise, probably associated with the plane engines, has been filtered out. Along profile data are compared with the Italian aeromagnetic grid as provided by the last version of the WDMAM (World Digital Magnetic Anomaly Map).

Lesur, V.; Schachtschneider, R.; Gebler, A.

2013-12-01

235

Fiber Optic Experience with the Smart Actuation System on the F-18 Systems Research Aircraft  

NASA Technical Reports Server (NTRS)

High bandwidth, immunity to electromagnetic interference, and potential weight savings have led to the development of fiber optic technology for future aerospace vehicle systems. This technology has been incorporated in a new smart actuator as the primary communication interface. The use of fiber optics simplified system integration and significantly reduced wire count. Flight test results showed that fiber optics could be used in aircraft systems and identified critical areas of development of fly-by-light technology. This paper documents the fiber optic experience gained as a result of this program, and identifies general design considerations that could be used in a variety of specific applications of fiber optic technology. Environmental sensitivities of fiber optic system components that significantly contribute to optical power variation are discussed. Although a calibration procedure successfully minimized the effect of fiber optic sensitivities, more standardized calibration methods are needed to ensure system operation and reliability in future aerospace vehicle systems.

Zavala, Eddie

1997-01-01

236

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

NASA Technical Reports Server (NTRS)

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 tests are presented.

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

1985-01-01

237

Definition of propulsion system for V/STOL research and technology aircraft  

NASA Technical Reports Server (NTRS)

Wind tunnel test support, aircraft contractor support, a propulsion system computer card deck, preliminary design studies, and propulsion system development plan are reported. The Propulsion system consists of two lift/cruise turbofan engines, one turboshaft engine and one lift fan connected together with shafting into a combiner gearbox. Distortion parameter levels from 40 x 80 test data were within the established XT701-AD-700 limits. The three engine-three fan system card deck calculates either vertical or conventional flight performance, installed or uninstalled. Design study results for XT701 engine modifications, bevel gear cross shaft location, fixed and tilt fan frames and propulsion system controls are described. Optional water-alcohol injection increased total net thrust 10.3% on a 90 F day. Engines have sufficient turbine life for 500 hours of the RTA duty cycle.

1977-01-01

238

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

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

239

Methane and nitrous oxide measurements onboard the UK Atmospheric Research Aircraft using quantum cascade laser spectrometry (QCL)  

NASA Astrophysics Data System (ADS)

A Aerodyne Research© Mini-Quantum Cascade Laser (QCL) spectrometer was installed on the UK Facility of Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft and employed during summer 2012. Methane (CH4) and nitrous oxide (N2O) concentrations were measured within the Arctic Circle as part of the MAMM project (Methane and other greenhouse gases in the Arctic - Measurements, process studies and Modelling) as well as around the UK as part of the ClearfLo project (Clean Air for London). A range of missions were flown, including deep vertical profiles up to the stratosphere, providing concentration profiles of CH4 and N2O, as well as low altitude level runs exploring near surface diffuse emission sources such as the wetlands in Arctic Lapland and point emissions sources such as gas platforms off the UK coast. Significant pollution plumes were observed both in the Arctic and around the UK with elevated CH4 concentrations, as well as enhanced CO, O3 and aerosol levels. The NAME Lagrangian particle dispersion model will be used to investigate the origins of these CH4 plumes to identify the locations of the emissions sources. The first set of flights using QCL on the FAAM research aircraft have been successful and regular in-flight calibrations (high/low span) and target concentrations were used to determine instrument accuracy and precision. Additional data quality control checks could be made by comparison with an onboard Los Gatos Fast Greenhouse Gas Analyser (FGGA) for CO2 and CH4 and provide the basis for further instrument development and implementation for future Arctic MAMM flights during spring and summer 2013.

Muller, J. B.; O'Shea, S.; Dorsey, J.; Bauguitte, S.; Cain, M.; Allen, G.; Percival, C. J.; Gallagher, M. W.

2012-12-01

240

Aircraft operations management manual  

NASA Technical Reports Server (NTRS)

The NASA aircraft operations program is a multifaceted, highly diverse entity that directly supports the agency mission in aeronautical research and development, space science and applications, space flight, astronaut readiness training, and related activities through research and development, program support, and mission management aircraft operations flights. Users of the program are interagency, inter-government, international, and the business community. This manual provides guidelines to establish policy for the management of NASA aircraft resources, aircraft operations, and related matters. This policy is an integral part of and must be followed when establishing field installation policy and procedures covering the management of NASA aircraft operations. Each operating location will develop appropriate local procedures that conform with the requirements of this handbook. This manual should be used in conjunction with other governing instructions, handbooks, and manuals.

1992-01-01

241

Flight Demonstration of X-33 Vehicle Health Management System Components on the F/A-18 Systems Research Aircraft  

NASA Technical Reports Server (NTRS)

The X-33 reusable launch vehicle demonstrator has identified the need to implement a vehicle health monitoring system that can acquire data that monitors system health and performance. Sanders, a Lockheed Martin Company, has designed and developed a commercial off-the-shelf (COTS)-based open architecture system that implements a number of technologies that have not been previously used in a flight environment. NASA Dryden Flight Research Center and Sanders teamed to demonstrate that the distributed remote health nodes, fiber optic distributed strain sensor, and fiber distributed data interface communications components of the X-33 vehicle health management (VHM) system could be successfully integrated and flown on a NASA F-18 aircraft. This paper briefly describes components of X-33 VHM architecture flown at Dryden and summarizes the integration and flight demonstration of these X-33 VHM components. Finally, it presents early results from the integration and flight efforts.

Schweikhard, Keith A.; Richards, W. Lance; Theisen, John; Mouyos, William; Garbos, Raymond; Schkolnik, Gerald (Technical Monitor)

1998-01-01

242

Transonic aerodynamic characteristics of a supersonic cruise aircraft research model with the engines suspended above the wing  

NASA Technical Reports Server (NTRS)

The influence of upper-surface nacelle exhaust flow on the aerodynamic characteristics of a supersonic cruise aircraft research configuration was investigated in a 16 foot transonic tunnel over a range of Mach numbers from 0.60 to 1.20. The arrow-wing transport configuration with engines suspended over the wing was tested at angles of attack from -4 deg to 6 deg and jet total pressure ratios from 1 to approximately 13. Wing-tip leading edge flap deflections of -10 deg to 10 deg were tested with the wing-body configuration. Various nacelle locations (chordwise, spanwise, and vertical) were tested over the ranges of Mach numbers, angles of attack, and jet total-pressure ratios. The results show that reflecting the wing-tip leading edge flap from 0 deg to -10 deg increased the maximum lift-drag ratio by 1.0 at subsonic speeds. Jet exhaust interference effects were negligible.

Mercer, C. E.; Carson, G. T., Jr.

1979-01-01

243

Gas- and Particle-phase Chemical Composition Measurements Onboard the G1 Research Aircraft during the CARES Campaign  

NASA Astrophysics Data System (ADS)

An Aerodyne High Resolution Aerosol Mass Spectrometer (AMS) and an Ionicon Proton Transfer Reaction Mass Spectrometer (PTRMS) were deployed on the G1 research aircraft during the CARES campaign in Sacramento, CA to investigate aerosol gas- and particle-phase chemical composition. Preliminary analysis of PTRMS data suggests that biogenic volatile organic compounds (VOCs), particularly isoprene, dominate the region with anthropogenic VOCs, such as benzene and toluene, providing much smaller contributions to the VOC pool. Data from the AMS shows that the particle phase is dominated by organic material with smaller concentrations of ammonium sulfate and ammonium nitrate observed. Organic particle mass concentration strongly correlated with isoprene and gas-phase isoprene oxidation products, suggesting isoprene chemistry is largely controlling the organic aerosol loading in the area. The chemical evolution of the plume as it traveled downwind from Sacramento and into the foothills will also be discussed.

Shilling, J. E.; Alexander, L.; Jayne, J.; Fortner, E.

2010-12-01

244

Flight Demonstration of X-33 Vehicle Health Management System Components on the F/A-18 Systems Research Aircraft  

NASA Technical Reports Server (NTRS)

The X-33 reusable launch vehicle demonstrator has identified the need to implement a vehicle health monitoring system that can acquire data that monitors system health and performance. Sanders, a Lockheed Martin Company, has designed and developed a COTS-based open architecture system that implements a number of technologies that have not been previously used in a flight environment. NASA Dryden Flight Research Center and Sanders teamed to demonstrate that the distributed remote health nodes, fiber optic distributed strain sensor, and fiber distributed data interface communications components of the X-33 vehicle health management (VHM) system could be successfully integrated and flown on a NASA F-18 aircraft. This paper briefly describes components of X-33 VHM architecture flown at Dryden and summarizes the integration and flight demonstration of these X-33 VHM components. Finally, it presents early results from the integration and flight efforts.

Schweikhard, Keith A.; Richards, W. Lance; Theisen, John; Mouyos, William; Garbos, Raymond

2001-01-01

245

A Model for Space Shuttle Orbiter Tire Side Forces Based on NASA Landing Systems Research Aircraft Test Results  

NASA Technical Reports Server (NTRS)

Forces generated by the Space Shuttle orbiter tire under varying vertical load, slip angle, speed, and surface conditions were measured using the Landing System Research Aircraft (LSRA). Resulting data were used to calculate a mathematical model for predicting tire forces in orbiter simulations. Tire side and drag forces experienced by an orbiter tire are cataloged as a function of vertical load and slip angle. The mathematical model is compared to existing tire force models for the Space Shuttle orbiter. This report describes the LSRA and a typical test sequence. Testing methods, data reduction, and error analysis are presented. The LSRA testing was conducted on concrete and lakebed runways at the Edwards Air Force Flight Test Center and on concrete runways at the Kennedy Space Center (KSC). Wet runway tire force tests were performed on test strips made at the KSC using different surfacing techniques. Data were corrected for ply steer forces and conicity.

Carter, John F.; Nagy, Christopher J.; Barnicki, Joseph S.

1997-01-01

246

Recent progress in research pertaining to estimates of gas-side heat transfer in an aircraft gas turbine  

NASA Technical Reports Server (NTRS)

A decade ago several important fundamental heat transfer phenomena were identified which were considered basic to the ability to predict heat transfer loads in aircraft gas turbines. The progress in addressing these fundamentals over the past ten years is assessed. Much reseach effort has been devoted to their study in university, industry and government labs and significant progress has been achieved. Advances in computer technology have enabled the modeling of complex 3-D fluid flow in gas turbines so necessary for heat transfer calculations. Advances in instrumentation plus improved data acquisition have brought about more reliable data sets. While much has advanced in the 1980's, much challenging research remains to be done. Several of these areas are suggested.

Graham, Robert W.

1989-01-01

247

Experimental and numerical research on the aerodynamics of unsteady moving aircraft  

NASA Astrophysics Data System (ADS)

For the experimental determination of the dynamic wind tunnel data, a new combined motion test capability was developed at the German-Dutch Wind Tunnels DNW for their 3 m Low Speed Wind Tunnel NWB in Braunschweig, Germany, using a unique six degree-of-freedom test rig called ‘Model Positioning Mechanism’ (MPM) as an improved successor to the older systems. With that cutting-edge device, several transport aircraft configurations including a blended wing body configuration were tested in different modes of oscillatory motions roll, pitch and yaw as well as delta-wing geometries like X-31 equipped with remote controlled rudders and flaps to be able to simulate realistic flight maneuvers, e.g., a Dutch Roll. This paper describes the motivation behind these tests and the test setup and in addition gives a short introduction into time accurate maneuver-testing capabilities incorporating models with remote controlled control surfaces. Furthermore, the adaptation of numerical methods for the prediction of dynamic derivatives is described and some examples with the DLR-F12 configuration will be given. The calculations are based on RANS-solution using the finite volume parallel solution algorithm with an unstructured discretization concept (DLR TAU-code).

Bergmann, Andreas; Huebner, Andreas; Loeser, Thomas

2008-02-01

248

Wet runways. [aircraft landing and directional control  

NASA Technical Reports Server (NTRS)

Aircraft stopping and directional control performance on wet runways is discussed. The major elements affecting tire/ground traction developed by jet transport aircraft are identified and described in terms of atmospheric, pavement, tire, aircraft system and pilot performance factors or parameters. Research results are summarized, and means for improving or restoring tire traction/aircraft performance on wet runways are discussed.

Horne, W. B.

1975-01-01

249

The Aircraft Morphing Program  

NASA Technical Reports Server (NTRS)

In the last decade smart technologies have become enablers that cut across traditional boundaries in materials science and engineering. Here we define smart to mean embedded actuation, sensing, and control logic in a tightly coupled feedback loop. While multiple successes have been achieved in the laboratory, we have yet to see the general applicability of smart devices to real aircraft systems. The NASA Aircraft Morphing program is an attempt to couple research across a wide range of disciplines to integrate smart technologies into high payoff aircraft applications. The program bridges research in seven individual disciplines and combines the effort into activities in three primary program thrusts. System studies are used to assess the highest- payoff program objectives, and specific research activities are defined to address the technologies required for development of smart aircraft systems. In this paper we address the overall program goals and programmatic structure, and discuss the challenges associated with bringing the technologies to fruition.

Wlezien, R. W.; Horner, G. C.; McGowan, A. R.; Padula, S. L.; Scott, M. A.; Silcox, R. J.; Simpson, J. O.

1998-01-01

250

Aircraft-vehicle system interaction. An evaluation of NASA's program in human factors research  

NASA Technical Reports Server (NTRS)

Research in the areas of man machine interaction and human factors engineering are assessed in relation to improved effeciency and aviation safety. The appropriateness, relevance, adequacy, and timeliness of the research is evaluated, and recommendations are provided regarding the objectives, approach and content.

1982-01-01

251

Flight evaluation of advanced controls and displays for transition and landing on the NASA V/STOL systems research aircraft  

NASA Technical Reports Server (NTRS)

Flight experiments were conducted on Ames Research Center's V/STOL Systems Research Aircraft (VSRA) to assess the influence of advanced control modes and head-up displays (HUD's) on flying qualities for precision approach and landing operations. Evaluations were made for decelerating approaches to hover followed by a vertical landing and for slow landings for four control/display mode combinations: the basic YAV-8B stability augmentation system; attitude command for pitch, roll, and yaw; flightpath/acceleration command with translational rate command in the hover; and height-rate damping with translational-rate command. Head-up displays used in conjunction with these control modes provided flightpath tracking/pursuit guidance and deceleration commands for the decelerating approach and a mixed horizontal and vertical presentation for precision hover and landing. Flying qualities were established and control usage and bandwidth were documented for candidate control modes and displays for the approach and vertical landing. Minimally satisfactory bandwidths were determined for the translational-rate command system. Test pilot and engineer teams from the Naval Air Warfare Center, the Boeing Military Airplane Group, Lockheed Martin, McDonnell Douglas Aerospace, Northrop Grumman, Rolls-Royce, and the British Defense Research Agency participated in the program along with NASA research pilots from the Ames and Lewis Research Centers. The results, in conjunction with related ground-based simulation data, indicate that the flightpath/longitudinal acceleration command response type in conjunction with pursuit tracking and deceleration guidance on the HUD would be essential for operation to instrument minimums significantly lower than the minimums for the AV-8B. It would also be a superior mode for performing slow landings where precise control to an austere landing area such as a narrow road is demanded. The translational-rate command system would reduce pilot workload for demanding vertical landing tasks aboard ship and in confined land-based sites.

Franklin, James A.; Stortz, Michael W.; Borchers, Paul F.; Moralez, Ernesto, III

1996-01-01

252

Braking performance of aircraft tires  

NASA Astrophysics Data System (ADS)

This paper brings under one cover the subject of aircraft braking performance and a variety of related phenomena that lead to aircraft hydroplaning, overruns, and loss of directional control. Complex processes involving tire deformation, tire slipping, and fluid pressures in the tire-runway contact area develop the friction forces for retarding the aircraft; this paper describes the physics of these processes. The paper reviews the past and present research efforts and concludes that the most effective way to combat the hazards associated with aircraft landings and takeoffs on contaminated runways is by measuring and displaying in realtime the braking performance parameters in the aircraft cockpit.

Agrawal, Satish K.

253

V/STOL tilt rotor research aircraft. Volume 1: General information, revision C  

NASA Technical Reports Server (NTRS)

The configuration, operation and maintenance requirements for the contractor-furnished portion of the XV-15 research instrumentation and data acquisition system are defined. Descriptions of systems operation, maintenance and checkout procedures, and cable designations are given.

Kimbell, M.; Whitener, A.

1980-01-01

254

OVRhyp, Scramjet Test Aircraft  

NASA Technical Reports Server (NTRS)

A preliminary design for an unmanned hypersonic research vehicle to test scramjet engines is presented. The aircraft will be launched from a carrier aircraft at an altitude of 40,000 feet at Mach 0.8. The vehicle will then accelerate to Mach 6 at an altitude of 100,000 feet. At this stage the prototype scramjet will be employed to accelerate the vehicle to Mach 10 and maintain Mach 10 flight for 2 minutes. The aircraft will then decelerate and safely land.

Aslan, J.; Bisard, T.; Dallinga, S.; Draper, K.; Hufford, G.; Peters, W.; Rogers, J.

1990-01-01

255

Airborne measurements of CO2 and CH4 onboard the UK FAAM research aircraft using a, Los Gatos Research Inc, cavity enhanced absorption spectrometer  

NASA Astrophysics Data System (ADS)

Airborne measurements of CO2 and CH4 have been made using the UK Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft since spring 2011.The measurement system uses a commercially available analyser, based on the off-axis integrated cavity output spectroscopy technique, from Los Gatos Research Inc (FGGA, Model RMT-200). During the first year of operation (29 flights), 1 Hz measurements were found to be accurate to 0.07 ± 2.48ppbv for CH4 and -0.06± 0.66ppmv for CO2. In summer 2011, as part of the BORTAS project (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites), outflow from boreal forest fires was measured in Eastern Canada. A number of fresh and photochemically-aged plumes were identified using simultaneous HCN measurements, a widely used tracer for biomass burning. In the freshest plumes, strong relationships were found between CH4, CO2 and other tracers for biomass burning. From this we were able to estimate that 6.9±0.8 g of CH4 and 1551±213 g of CO2 were released into the atmosphere per kg of dry matter burnt. These emission factors are in good agreement with estimates from previous studies in boreal regions. However for aged plumes the correlations between CH4 and other biomass burning tracers were not as robust, most likely due to mixing from other CH4 emission sources, such as the wetland regions. The role of additional emission sources will be investigated using the UK Met Office NAME atmospheric dispersion model and the HYSPLIT trajectory model. Using tailored back trajectory analysis, we will present an interpretation of this new dataset in the context of air mass/fire origin, relating this to MODIS fire maps and source strength.

O'Shea, S.; Bauguitte, S.; Muller, J. B.; Le Breton, M.; Gallagher, M. W.; Allen, G.; Percival, C. J.

2012-12-01

256

Design of a high-performance rotary stratified-charge research aircraft engine  

NASA Technical Reports Server (NTRS)

The power section for an advanced rotary stratified-charge general aviation engine has been designed under contract to NASA. The single-rotor research engine of 40 cubic-inches displacement (RCI-40), now being procured for test initiation this summer, is targeted for 320 T.O. horse-power in a two-rotor production engine. The research engine is designed for operating on jet-fuel, gasoline or diesel fuel and will be used to explore applicable advanced technologies and to optimize high output performance variables. Design of major components of the engine is described in this paper.

Jones, C.; Mount, R. E.

1984-01-01

257

Researcher's guide to the NASA Ames Flight Simulator for Advanced Aircraft (FSAA)  

NASA Technical Reports Server (NTRS)

Performance, limitations, supporting software, and current checkout and operating procedures are presented for the flight simulator, in terms useful to the researcher who intends to use it. Suggestions to help the researcher prepare the experimental plan are also given. The FSAA's central computer, cockpit, and visual and motion systems are addressed individually but their interaction is considered as well. Data required, available options, user responsibilities, and occupancy procedures are given in a form that facilitates the initial communication required with the NASA operations' group.

Sinacori, J. B.; Stapleford, R. L.; Jewell, W. F.; Lehman, J. M.

1977-01-01

258

Start Up Research Effort in Fluid Mechanics. Advanced Methods for Acoustic and Thrust Benefits for Aircraft Engine Nozzle  

NASA Technical Reports Server (NTRS)

In accordance with the project plan for the report period in the proposal titled above, HU and FML teams investigated two sets of concepts for reduction of noise and improvement in efficiency for jet exhaust nozzles of aircraft engines and screws for mixers, fans, propellers and boats. The main achievements in the report period are: (a) Publication of the paper in the AIAA Journal, which described our concepts and some results. (b) The Award in the Civil Research and Development Foundation (CRDF) competition. This 2 year grant for Hampton University (HU) and Central AeroHydrodynamic Institute (TSAGI, Moscow, Russia) supports the research implementation under the current NASA FAR grant. (c) Selection for funding by NASA HQ review panel of the Partnership Awards Concept Paper. This two year grant also will support our current FAR grant. (d) Publication of a Mobius Strip concept in NASA Technical Briefs, June, 1996, and a great interest of many industrial companies in this invention. Successful experimental results with the Mobius shaped screw for mixers, which save more than 30% of the electric power by comparison with the standard screws. Creation of the scientific-popular video-film which can be used for commercial and educational purposes. (e) Organization work, joint meetings and discussions of the NASA LARC JNL Team and HU professors and administration for the solution of actual problems and effective work of the Fluid Mechanics Laboratory at Hampton University. In this report the main designs are enumerated. It also contains for both concept sets: (1) the statement of the problem for each design, some results, publications, inventions, patents, our vision for continuation of this research, and (2) present and expected problems in the future.

White, Samuel G.; Gilinsky, Mikhail M.

1997-01-01

259

Environmental research brief: Pollution prevention assessment for a manufacturer of aircraft landing gear  

SciTech Connect

The US Environmental Protection Agency (EPA) has funded a Pilot project to assist small and medium-size manufacture who want to minimize their generation of waste but who lac the expertise to do so. In an effort to assist these manufacturers Waste Minimization Assessment Centers (WMACs) we established at selected universities and procedures were adapted from the EPA Waste Minimization Opportunity Assessment Manual. The WMAC team at the University of Tennessee performed an assessment at a plant that manufactures outboard motors for water craft. Three basic subunits received from other manufacturing plants undergo primarily painting and assembly operations in order to produce the final product. The team`s report, detailing findings and recommendations, indicated that paint overspray waste and spent clean-up solvent are generated in large quantities and that significant cost savings could be achieved by installing robotic paint application equipment. This Research Brief was developed by the principal investigators and EPA`s National Risk Management Research Laboratory, Cincinnati, OH, to announce key findings of an ongoing research project that is fully documented in a separate report of the same title available from University City Science Center.

Jendrucko, R.J.; Morton, S.D.; Thomas, T.M. [Tennessee Univ., Knoxville, TN (United States). Dept. of Engineering Science and Mechanics; Looby, G.P. [University City Science Center, Philadelphia, PA (United States)

1995-08-01

260

Mystery Aircraft  

NSDL National Science Digital Library

The Federation of American Scientists offers this unique perspective into classified government aircraft, "some of which actually exist, some of which certainly do not, and all of which are fascinating in a way." This site is divided into two main sections. The first provides insight into several aircraft that were initially shrouded in secrecy but have since been revealed to the public. Some examples include the SR-71, the B-2, and the Hyper-X. The second section is devoted to aircraft that may or may not be currently under development or in operation by the US government. The much popularized Aurora is in this section, as well as exotic propulsion aircraft.

261

Real-time flutter analysis of an active flutter-suppression system on a remotely piloted research aircraft  

NASA Technical Reports Server (NTRS)

Flight flutter-test results of the first aeroelastic research wing (ARW-1) of NASA's drones for aerodynamic and structural testing program are presented. The flight-test operation and the implementation of the active flutter-suppression system are described as well as the software techniques used to obtain real-time damping estimates and the actual flutter testing procedure. Real-time analysis of fast-frequency aileron excitation sweeps provided reliable damping estimates. The open-loop flutter boundary was well defined at two altitudes; a maximum Mach number of 0.91 was obtained. Both open-loop and closed-loop data were of exceptionally high quality. Although the flutter-suppression system provided augmented damping at speeds below the flutter boundary, an error in the implementation of the system resulted in the system being less stable than predicted. The vehicle encountered system-on flutter shortly after crossing the open-loop flutter boundary on the third flight and was lost. The aircraft was rebuilt. Changes made in real-time test techniques are included.

Gilyard, G. B.; Edwards, J. W.

1983-01-01

262

NASA Agricultural Aircraft Research Program in the Langley Vortex Research Facility and the Langley Full Scale Wind Tunnel  

NASA Technical Reports Server (NTRS)

The current status of aerial applications technology research at the Langley's Vortex Research Facility and Full-Scale Wind Tunnel is reviewed. Efforts have been directed mainly toward developing and validating the required experimental and theoretical research tools. A capability to simulate aerial dispersal of materials from agricultural airplanes with small-scale airplane models, numerical methods, and dynamically scaled test particles was demonstrated. Tests on wake modification concepts have proved the feasibility of tailoring wake properties aerodynamically to produce favorable changes in deposition and to provide drift control. An aerodynamic evaluation of the Thrush Commander 800 agricultural airplane with various dispersal systems installed is described. A number of modifications intended to provide system improvement to both airplane and dispersal system are examined, and a technique for documenting near-field spray characteristics is evaluated.

Jordan, F. L., Jr.; Mclemore, H. C.; Bragg, M. B.

1978-01-01

263

Programme of Research into the Aerodynamics, Stability and Control Characteristics of a Combat Aircraft Having a Forward Swept Wing.  

National Technical Information Service (NTIS)

The aerodynamic stability and control characteristics of the forward swept wing aircraft, and likely stability augmentation requirements were studied. It is found that: (1) the theoretical aerodynamic models match the observed aerodynamic performance; (2)...

M. V. Cook F. Heydari

1985-01-01

264

Probing Aircraft Flight Test Hazard Mitigation for the Alternative Fuel Effects on Contrails & Cruise Emissions (ACCESS) Research Team  

NASA Technical Reports Server (NTRS)

The Alternative Fuel Effects on Contrails & Cruise Emissions (ACCESS) Project Integration Manager requested in July 2012 that the NASA Engineering and Safety Center (NESC) form a team to independently assess aircraft structural failure hazards associated with the ACCESS experiment and to identify potential flight test hazard mitigations to ensure flight safety. The ACCESS Project Integration Manager subsequently requested that the assessment scope be focused predominantly on structural failure risks to the aircraft empennage raft empennage.

Kelly, Michael J.

2013-01-01

265

Research on the Effects of Fatigue within the Corporate/Business Aircraft Environment  

NASA Technical Reports Server (NTRS)

In 1980, responding to a Congressional request, NASA Ames Research Center created a program to examine whether 'there is a safety problem of uncertain magnitude, due to transmeridian flying and a potential problem due to fatigue in association with various factors found in air transport operations.' The NASA Ames Fatigue/Jet Lag Program was created to collect systematic, scientific information on fatigue, sleep, circadian rhythms, and performance in flight operations. Three Program goals were established and continue to guide research efforts to: (1) determine the extent of fatigue, sleep loss, and circadian disruption in flight operations; (2) determine the impact of these factors on flight crew performance; (3) develop and evaluate countermeasures to mitigate the adverse effects of these factors and maximize flight crew performance and alertness. Since 1980, studies have been conducted in a variety of aviation environments, in controlled laboratory environments, as well as in a full-mission flight simulation. Early studies included investigations of short-haul, long-haul, and overnight cargo flight crews. In 1991, the name of the program was changed to the Fatigue Countermeasures Program to provide a greater emphasis on the development and evaluation of countermeasures. More recent work has examined the effects of planned cockpit rest as an operational countermeasure and provided analyses of the pertinent sleep/duty factors preceding an aviation accident at Guantanamo Bay, Cuba. The Short-Haul study examined the extent of sleep loss, circadian disruption, and fatigue engendered by flying commercial short-haul air transport operations (flight legs less than eight hours). This was one of the first field studies conducted by the NASA program and provided unique insight into the physiological and subjective effects of flying commercial short-haul operations. It demonstrated that a range of measures could be obtained in an operational environment without disturbing the regular performance of duties. The Long-Haul study examined how long-haul flight crews organized their sleep during a variety of international trip patterns and examined how duty requirements, local time, and the circadian system affected the timing, duration, and quality of sleep. Duty requirements and local time can be viewed as external/environmental constraints on time available for sleep, while the internal circadian system is a major physiological modulator of sleep duration and quality. The Overnight Cargo study documented the psychophysiological effects of flying overnight cargo operations. The data collected clearly demonstrated that overnight cargo operations, like other night work, involve physiological disruption not found in comparable daytime operations.

Neri, David F.; Rosekind, Mark R.; Co, Elizabeth L.; Gregory, Kevin B.; Miller, Donna L.

1997-01-01

266

NASA's F-15B Research Testbed aircraft flies in the supersonic shock wave of a U.S. Navy F-5E as par  

NASA Technical Reports Server (NTRS)

NASA's F-15B Research Testbed aircraft recently flew in the supersonic shock wave of a U.S. Navy F-5E in support of the F-5 Shaped Sonic Boom Demonstration (SSBD) project, part of the Defense Advanced Research Projects Agency's (DARPA) Quiet Supersonic Platform (QSP) program. The flights originated from the NASA Dryden Flight Research Center at Edwards, California. Four flights were flown in order to measure the F-5E's near-field (close-up) sonic boom signature at Mach 1.4, during which more than 50 shockwave patterns were measured at distances as close as 100 feet below the F-5E.

2002-01-01

267

Alternate Fuels for use in Commercial Aircraft  

Microsoft Academic Search

The engine and commercial aircraft research and development communities have been investigating the practicality of using alternative fuels in near, mid, and far-term aircraft. Presently, it appears that an approach of using a \\

David L. Daggett; Robert C. Hendricks; Edwin Corporan

268

Dryden Aircraft Photo Collection  

NSDL National Science Digital Library

Any lover of airplanes is bound to enjoy this collection of digitized photos "of many of the unique research aircraft" from the NASA Dryden Flight Research Center in Edwards, California. The photos go back to the 1940s and into the present. Multiple resolutions are available. The collection is regularly updated. Visitors can browse the entire list alphabetically, or go right to the most recent postings in "What's New" or check out the Slide Show of selected photos. Each photo is accompanied by a short description of the aircraft's flight history. Some other miscellaneous photos include the shock wave of a T-38 at Mach 1.1 and photos of Dryden pilots.

269

Aircraft Flutter Testing  

NASA Technical Reports Server (NTRS)

Wilmer Reed gained international recognition for his innovative research, contributions and patented ideas relating to flutter and aeroelasticity of aerospace vehicles at Langley Research Center. In the early 1980's, Reed retired from Langley and joined the engineering staff of Dynamic Engineering Inc. While at DEI, Reed conceived and patented the DEI Flutter Exciter, now used world-wide in flight flutter testing of new or modified aircraft designs. When activated, the DEI Flutter Exciter alternately deflects the airstream upward and downward in a rapid manner, creating a force similar to that produced by an oscillating trailing edge flap. The DEI Flutter Exciter is readily adaptable to a variety of aircraft.

1997-01-01

270

Pilot Comments From the Boeing High Speed Research Aircraft, Cycle 3, Simulation Study of the Effects of Aeroservoelasticity (LaRC.3)  

NASA Technical Reports Server (NTRS)

This is a compilation of pilot comments from the Boeing High Speed Research Aircraft, Cycle 3, simulation study (LaRC.3) of the effects of aeroservoelasticity, conducted from October to December 1997 at NASA Langley Research Center. This simulation study was conducted using the Visual Motion Simulator. The comments are from direct tape transcriptions and have been edited for spelling only. These comments were made on tape following the completion of each flight card, immediately after the pilot was satisfied with his practice and data recording runs. Six pilots were used in the evaluation and they are identified as pilots A through F.

Bailey, Melvin L. (Editor)

2000-01-01

271

Pilotless Aircraft Research Division  

NASA Technical Reports Server (NTRS)

The launching of the first rocket at the NACA's Wallop's Island Facility on June 27, 1945. Joseph Shortal described this launch as follows: 'The initial operations on June 27, 1945 on Wallops were to check the tracking station location and operation, check the use of CW (Doppler radar for measuring velocities of missiles and to gain experience with actual rockets. Five 3.25 inch rockets were fired at 39.4 elevation angle, and one each at 33.7, 29.3, and 21.5. All were fired in a direction parallel to the beach to simulate the first Tiamat missile launching. Four of the eight rockets were tracked satisfactorily by the SCR-584 radar located at the mainland tracking station 2 and a strong signal was obtained on the CW radar. As [Ray W.] Hooker stated in his official report on the operations, 'In general, the operation was successful.' [Germain S.] Brown, in his diary expressed it this way: 'Hooker and gang arrived by B24 at 10:30. Went to Island and launched about eight rockets with satisfactory results. Lt. Rucker and 3 Navy enlisted men assisted us.' 'For this operation the rockets and the ordnance personnel were supplied by the Patuxent Naval Air Station. Navy Buaer had established a special project to cover this cooperation with NACA.' Excerpts from Joseph Shortal's history of Wallops Station.

1945-01-01

272

Aircraft equipment  

NASA Technical Reports Server (NTRS)

The complex of functionally interconnected instruments and devices for controlling flight, engine operations, electrical systems, communications, and vital systems for passengers and crew is described. The aggregates of the aircraft automatic equipment are also discussed.

1977-01-01

273

Drone, Aircraft.  

National Technical Information Service (NTIS)

The report describes test methods and techniques for evaluating the technical performance and characteristics of drone aircraft. The evaluation is related to criteria expressed in applicable qualitative materiel requirements, small development requirement...

1970-01-01

274

Aircraft Industry.  

National Technical Information Service (NTIS)

The aircraft industry plays a critical role in today's global economy. Comprising a wide array of firms supplying various products and services to a diverse and dynamic customer base, this industry represents a compelling case study from three distinct pe...

B. Braley D. Bereda F. M. Al Garni J. Bojarski J. Spicer

2007-01-01

275

Alternative aircraft fuels technology  

NASA Technical Reports Server (NTRS)

NASA is studying the characteristics of future aircraft fuels produced from either petroleum or nonpetroleum sources such as oil shale or coal. These future hydrocarbon based fuels may have chemical and physical properties that are different from present aviation turbine fuels. This research is aimed at determining what those characteristics may be, how present aircraft and engine components and materials would be affected by fuel specification changes, and what changes in both aircraft and engine design would be required to utilize these future fuels without sacrificing performance, reliability, or safety. This fuels technology program was organized to include both in-house and contract research on the synthesis and characterization of fuels, component evaluations of combustors, turbines, and fuel systems, and, eventually, full-scale engine demonstrations. A review of the various elements of the program and significant results obtained so far are presented.

Grobman, J.

1976-01-01

276

Aircraft Sensor Quality in SESAME 1979: Results of Tower Fly-bys and Aircraft Intercomparison.  

National Technical Information Service (NTIS)

Instrumented research aircraft data quality during Project SESAME '79 is examined in a series of tower fly-bys, designed to compare temperature and static pressure measurements with reference values obtained from sensors located on the towers. Aircraft st...

D. E. Ziegler J. McCarthy

1980-01-01

277

Considerations for Clearance of Civil Transport Aircraft  

Microsoft Academic Search

This chapter reflects on the previous chapters to present a civil aircraft perspective to clearance. It briefly describes\\u000a the common areas and differences between the clearance of flight control laws (FCLs) of civil transport aircraft and fighter aircraft. It evaluates and discusses the applicability of the presented FCL\\u000a clearance techniques for civil aircraft and gives some recommendations for future research.

Robert Luckner; Airbus Deutschland

278

Aircraft Design Analysis  

NASA Technical Reports Server (NTRS)

The helicopter pictured is the twin-turbine S-76, produced by Sikorsky Aircraft division of United Technologies, Stratford, Connecticut. It is the first transport helicopter ever dey n e d purely as a commercial vehicle rather than an adaptation of a military design. Being built in large numbers for customers in 16 countries, the S-76 is intended for offshore oil rig support, executive transportation and general utility service. The craft carries 12 passengers plus a crew of two and has a range of more than 450 miles-yet it weighs less than 10,000 pounds. Significant weight reduction was achieved by use of composite materials, which are generally lighter but stronger than conventional aircraft materials. NASA composite technology played a part in development of the S-76. Under contract with NASA's Langley Research Center, Sikorsky Aircraft designed and flight-tested a helicopter airframe of advanced composite materials.

1979-01-01

279

High altitude reconnaissance aircraft  

NASA Technical Reports Server (NTRS)

At the equator the ozone layer ranges from 65,000 to 130,000 plus feet, which is beyond the capabilities of the ER-2, NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozone layer at the equator. This aircraft must be able to cruise at 130,000 feet for six hours at Mach 0.7, while carrying 3,000 lbs. of payload. In addition, the aircraft must have a minimum range of 6,000 miles. In consideration of the novel nature of this project, the pilot must be able to take control in the event of unforeseen difficulties. Three aircraft configurations were determined to be the most suitable - a joined-wing, a biplane, and a twin-boom conventional airplane. The performance of each configuration was analyzed to investigate the feasibility of the project.

Yazdo, Renee Anna; Moller, David

1990-01-01

280

Survey on effect of surface winds on aircraft design and operation and recommendations for needed wind research  

NASA Technical Reports Server (NTRS)

A survey of the effect of environmental surface winds and gusts on aircraft design and operation is presented. A listing of the very large number of problems that are encountered is given. Attention is called to the many studies that have been made on surface winds and gusts, but development in the engineering application of these results to aeronautical problems is pointed out to be still in the embryonic stage. Control of the aircraft is of paramount concern. Mathematical models and their application in simulation studies of airplane operation and control are discussed, and an attempt is made to identify their main gaps or deficiencies. Key reference material is cited. The need for better exchange between the meteorologist and the aeronautical engineer is discussed. Suggestions for improvements in the wind and gust models are made.

Houbolt, J. C.

1973-01-01

281

Structural Dynamics of Maneuvering Aircraft.  

National Technical Information Service (NTIS)

The technical objectives of the research are to establish the minimum level of modeling necessary for predicting the dynamic stresses in fighter aircraft during maneuvers and transitions between maneuvers, to identify the physical phenomena which are sign...

M. M. Reddi

1987-01-01

282

Provisioning an Aircraft Weapons System.  

National Technical Information Service (NTIS)

The research reviews the elements and stages of the provisioning cycle and describes the provisioning model used by the United States Navy Aviation Supply Office to select a repair parts inventory for an operational site supporting a new aircraft weapons ...

R. B. Renner

1975-01-01

283

Aircraft Electrical Generators.  

National Technical Information Service (NTIS)

Contents: General Information on Aircraft Electrical Machines General Information on Aircraft Generators Alternating-Current Aircraft Generators Permanent-Magnet Generators Induction Generators Direct-Current Aircraft Generators Parallel Operation of Airc...

A. I. Bertinov

1964-01-01

284

Rapid, optical measurement of the atmospheric pressure on a fast research aircraft using open-path TDLAS  

NASA Astrophysics Data System (ADS)

Because of the high travel speed, the complex flow dynamics around an aircraft and the complex dependency of the fluid dynamics on numerous airborne parameters, it is quite difficult to obtain accurate pressure values at a specific instrument location of an aircraft's fuselage. Complex simulations using computational fluid dynamics (CFD) models can in theory computationally "transfer" pressure values from one location to another. However, for long flight patterns, this process is inconvenient and cumbersome. Furthermore these CFD transfer models require a local experimental validation, which is rarely available. In this paper, we describe an integrated approach for a spectroscopic, calibration-free, in-flight pressure determination in an open-path White cell on an aircraft fuselage using ambient, atmospheric water vapour as the "sensor species". The presented measurements are realized with the HAI (Hygrometer for Atmospheric Investigations) instrument, built for multiphase water detection via calibration-free TDLAS (tunable diode laser absorption spectroscopy). The pressure determination is based on raw data used for H2O concentration measurement, but with a different post-flight evaluation method, and can therefore be conducted at deferred time intervals on any desired flight track. The spectroscopic pressure is compared in-flight with the static ambient pressure of the aircraft avionic system and a micro-mechanical pressure sensor, located next to the open-path cell, over a pressure range from 150 hPa to 800 hPa, and a water vapour concentration range of more than three orders of magnitude. The correlation between the micro-mechanical pressure sensor measurements and the spectroscopic pressure measurements show an average deviation from linearity of only 0.14% and a small offset of 9.5 hPa. For the spectroscopic pressure evaluation we derive measurement uncertainties under laboratory conditions of 3.2% and 5.1% during in flight operation on the HALO airplane. Under certain flight conditions we quantified for the first time stalling-induced, dynamic pressure deviations of up to 30% (at 200 hPa) between the avionic sensor and the optical and mechanical pressure sensors integrated in HAI. Such severe local pressure deviations from the usually used avionic pressure are important to take into account for other airborne sensors employed on such fast flying platforms as the HALO aircraft.

Buchholz, B.; Afchine, A.; Ebert, V.

2014-05-01

285

Neural networks for aircraft control  

NASA Technical Reports Server (NTRS)

Current research in Artificial Neural Networks indicates that networks offer some potential advantages in adaptation and fault tolerance. This research is directed at determining the possible applicability of neural networks to aircraft control. The first application will be to aircraft trim. Neural network node characteristics, network topology and operation, neural network learning and example histories using neighboring optimal control with a neural net are discussed.

Linse, Dennis

1990-01-01

286

An Electronic Workshop on the Performance Seeking Control and Propulsion Controlled Aircraft Results of the F-15 Highly Integrated Digital Electronic Control Flight Research Program  

NASA Technical Reports Server (NTRS)

Flight research for the F-15 HIDEC (Highly Integrated Digital Electronic Control) program was completed at NASA Dryden Flight Research Center in the fall of 1993. The flight research conducted during the last two years of the HIDEC program included two principal experiments: (1) performance seeking control (PSC), an adaptive, real-time, on-board optimization of engine, inlet, and horizontal tail position on the F-15; and (2) propulsion controlled aircraft (PCA), an augmented flight control system developed for landings as well as up-and-away flight that used only engine thrust (flight controls locked) for flight control. In September 1994, the background details and results of the PSC and PCA experiments were presented in an electronic workshop, accessible through the Dryden World Wide Web (http://www.dfrc.nasa.gov/dryden.html) and as a compact disk.

Powers, Sheryll Goecke (compiler)

1995-01-01

287

Measurements of nitrogen oxides in the UTLS: Results from the TACTS and ESMVal mission using the new German research aircraft HALO  

NASA Astrophysics Data System (ADS)

In summer 2012 the new German research aircraft HALO (High Altitude and LOng range research aircraft) took off for its first missions to study atmospheric chemistry and transport. During the TACTS (Transport and Composition in the UTLS) mission the main focus laid on transport processes in the UTLS determining the chemical composition at midlatitudes. The ESMVal (Earth System Model validation) mission aimed at the study of the large scale composition of trace species along a north-south transect between the North and South Polar Region (about 80°N to 65°S). Both missions have been carried out with the same scientific payload. Here we report on measurements of nitrogen oxide (NO) and the sum of all atmospheric reactive nitrogen species (NOy). Nitrogen oxides have a decisive influence on the chemistry of the upper troposphere and lower stratosphere. They are key constituents of several reaction chains influencing the production of ozone. They also play an essential role in the cycling of hydroxyl radicals and therefore influence the lifetime of methane. Due to their short lifetimes and their variety of sources there is still a high uncertainty about the abundance of nitrogen oxides in the UTLS. During both missions the large scale distribution of NO and NOy was observed in the UTLS covering regions with different source characteristics. Among others, signatures of biomass burning events and lightning activity were detected. Also North and South Polar regions were probed. The acquired data are compared to other aircraft observations (e.g. CARIBIC) and to the results of simulations with the atmospheric chemistry model EMAC.

Ziereis, Helmut; Stock, Paul; Schlager, Hans; Gottschaldt, Klaus-Dirk; Boenisch, Harald; Engel, Andreas; Zahn, Andreas; Hoor, Peter

2014-05-01

288

From Germany to Antarctica: Airborne geodesy and geophysics and the utilization of the research aircraft HALO (Invited)  

NASA Astrophysics Data System (ADS)

The geoid as an equipotential surface of the gravity potential plays a crucial role for the realiziation of the Global Geodetic Observation System (GGOS) of IAG (International Association of Geodesy). It is the major reference surface for physical height systems. The gravity potential is needed to precisely predict the orbits of artificial satellites of the earth. A precise static solution enters analyses of temporal changes of the gravity field due to mass transport processes between the different subsystems of the earth. However, also in neighbouring disciplines the geoid is applied. In oceanography, for example, the geoid serves as a reference surface for the determination of the mean sea-surface topography (MSST). In glaciology, it enters analyses of the thickness of ice bodies floating in polar waters, based on freeboard heights and the equilibrium supposition. To come up with high resolution global gravity field models, satellite observations - preferably of the dedicated satellite gravity missions - have to be combined with surface gravity data. Although the majority of the continental surface is captured by ground-based or near-surface gravity measurements - and gravity over the oceans is determined by satellite altimetry - still large gaps in surface gravity data exist. In this respect it is the Antarctic continent which suffers large data gaps, not only in surface gravity but also due to the polar gap of GOCE satellite gravimetry. Chairing the IAG Subcommission 2.4f 'Gravity and Geoid in Antarctica' (AntGG) the author will discuss the current status of gravity surveys in Antarctica. Especially airborne gravimetry has been and is being widely applied as the only reasonable method to survey large areas in this vast and hostile environment. As a novel application the German research aircraft HALO was utilized for a geodetic-geophysical flight mission. Measurements were realized to acquire data of the gravity and magnetic fields, of GNSS remote sensing and of laser altimetry over Italy and adjacent (Tyrrhenian, Adriatic and Ionian) seas. This so-called GEOHALO flight mission was carried out in the time period from June 2 to 12, 2012. The flights comprised seven parallel profiles directing from north-west to south-east, in a height of about 3,500 m, with a length of about 1,000 km each and a line spacing of about 40 km. These long profiles were complemented by four crossing profiles and a profile at an altitude of approx. 10 km along the same track as the center long profile. Special focus will be given to the results of airborne gravimetry and laser altimetry to further investigate the gravity field and the sea-surface topography in the Mediterranean. Furthermore, the status of HALO and future plans to utilize HALO for an Antarctic flight mission will be discussed. Applications of airborne gravimetry to investigate geodetic problems in Antarctica shall be shortly discussed, together with an outlook of AntGG.

Scheinert, M.; Barthelmes, F.; Foerste, C.; Heyde, I.

2013-12-01

289

Aircraft cybernetics  

NASA Technical Reports Server (NTRS)

The use of computers for aircraft control, flight simulation, and inertial navigation is explored. The man-machine relation problem in aviation is addressed. Simple and self-adapting autopilots are described and the assets and liabilities of digital navigation techniques are assessed.

1977-01-01

290

Aircraft Contrails  

NSDL National Science Digital Library

NASA's Earth Observatory "Aircraft Contrails" webpage summarizes the key mechanism, measurements, and predictions of how cirrus clouds produced by contrails contribute to global warming. The page also includes an image showing a large number of contrails produced over the southeastern U. S.

Observatory, Nasa E.

2011-09-15

291

Perspectives on Highly Adaptive or Morphing Aircraft  

NASA Technical Reports Server (NTRS)

The ability to adapt to different flight conditions has been fundamental to aircraft design since the Wright Brothers first flight. Over a hundred years later, unconventional aircraft adaptability, often called aircraft morphing has become a topic of considerable renewed interest. In the past two decades, this interest has been largely fuelled by advancements in multi-functional or smart materials and structures. However, highly adaptive or morphing aircraft is certainly a cross-discipline challenge that stimulates a wide range of design possibilities. This paper will review some of the history of morphing aircraft including recent research programs and discuss some perspectives on this work.

McGowan, Anna-Maria R.; Vicroy, Dan D.; Busan, Ronald C.; Hahn, Andrew S.

2009-01-01

292

The use of the National Research Council of Canada's Falcon 20 research aircraft as a terrestrial analogue space environment (TASE) for space surgery research: Challenges and suggested solutions  

Microsoft Academic Search

Emergency surgery will be needed to prevent death if humans are used to explore beyond low earth's orbit. Laparoscopic surgery (LS) is envisioned as a less invasive option for space, but will induce further stresses and complicate logistical requirements. Thus, further study into the technology and physiology of LS in weightlessness is required. We recently utilized the National Research Council

A. W. Kirkpatrick; M. A. Keaney; K. Bentz; M. Groleau; M. Tyssen; J. Keyte; C. G. Ball; M. R. Campbell; S. M. Grenon; P. McBeth; T. J. Broderick

2010-01-01

293

Designing for aircraft structural crashworthiness  

NASA Technical Reports Server (NTRS)

This report describes structural aviation crash dynamics research activities being conducted on general aviation aircraft and transport aircraft. The report includes experimental and analytical correlations of load-limiting subfloor and seat configurations tested dynamically in vertical drop tests and in a horizontal sled deceleration facility. Computer predictions using a finite-element nonlinear computer program, DYCAST, of the acceleration time-histories of these innovative seat and subfloor structures are presented. Proposed application of these computer techniques, and the nonlinear lumped mass computer program KRASH, to transport aircraft crash dynamics is discussed. A proposed FAA full-scale crash test of a fully instrumented radio controlled transport airplane is also described.

Thomson, R. G.; Caiafa, C.

1981-01-01

294

Understanding the Role of the Saharan Heat Low in Modifying Atmospheric Dust Distributions - Observations From Two Research Aircraft Flying Simultaneously Over Western Africa  

NASA Astrophysics Data System (ADS)

The near-surface low pressure system that develops over western Africa in Boreal summer (know as the Saharan Heat Low) is thought to have a significant influence on regional and global climate due to its links with the Monsoon, the Northern Atlantic and the Mediterranean climate system. The SHL is associated with the deepest atmospheric boundary layer on the planet and is co-located with the highest dust loadings in the world. The processes that link the heat low and dust distribution are only poorly understood. Improving the representation of the heat low and the processes that control the emission and atmospheric distribution of dust in climate and NWP models is crucial if we are to reduce known systematic errors in climate predictions and weather forecasts. In collaboration with European partners, the UK-based consortium project "Fennec - The Saharan Climate System" aims at improving our understanding of this complex climate system by integrating for the first time coordinated ground and aircraft observations from the central Sahara, newly developed satellite products, and the application of regional and global models. On 22 June 2011, two research aircraft operating out of Fuerteventura (Spain) surveyed the Saharan Heat Low centred over Mauritania-Mali border. The aircraft flew simultaneously in the morning and in the afternoon on two different tracks thereby sampling each track four times on that day. Both aircraft were equipped with a downward looking LIDAR for aerosol detection. In total, 51 sondes were dropped during the flights making this the most comprehensive dataset to study the spatio-temporal diurnal evolution of the heat low including the interactions between the atmospheric boundary layer and dust distributions. Combining LIDAR observations, satellite imagery and back-trajectory modelling we show that an aged dust layer was present in the heat low region resulting from previous day's dust activity associated with a south-moving density current from the Atlas mountains and westward-moving Haboob fronts originating along the Algeria-Mali border. We show how the dust is distributed within the atmosphere and how it is modified during the course of the day by various processes including the development of the atmospheric boundary layer and associated dry convection as well as the inflow of moisture-rich monsoon air from the south.

Engelstaedter, S.; Washington, R.; Allen, C.; Flamant, C.; Chaboureau, J.-P.; Kocha, C.; Lavaysse, C.

2012-04-01

295

Aircraft noise prediction  

NASA Astrophysics Data System (ADS)

This contribution addresses the state-of-the-art in the field of aircraft noise prediction, simulation and minimisation. The point of view taken in this context is that of comprehensive models that couple the various aircraft systems with the acoustic sources, the propagation and the flight trajectories. After an exhaustive review of the present predictive technologies in the relevant fields (airframe, propulsion, propagation, aircraft operations, trajectory optimisation), the paper addresses items for further research and development. Examples are shown for several airplanes, including the Airbus A319-100 (CFM engines), the Bombardier Dash8-Q400 (PW150 engines, Dowty R408 propellers) and the Boeing B737-800 (CFM engines). Predictions are done with the flight mechanics code FLIGHT. The transfer function between flight mechanics and the noise prediction is discussed in some details, along with the numerical procedures for validation and verification. Some code-to-code comparisons are shown. It is contended that the field of aircraft noise prediction has not yet reached a sufficient level of maturity. In particular, some parametric effects cannot be investigated, issues of accuracy are not currently addressed, and validation standards are still lacking.

Filippone, Antonio

2014-07-01

296

Recommendations for ground effects research for V/STOL and STOL aircraft and associated equipment for large scale testing  

NASA Technical Reports Server (NTRS)

The current understanding of the effects of ground proximity on V/STOL and STOL aircraft is reviewd. Areas covered include (1) single jet suckdown in hover, (2) fountain effects on multijet configurations, (3) STOL ground effects including the effect of the ground vortex flow field, (4) downwash at the tail, and (5) hot gas ingestion in both hover and STOL operation. The equipment needed for large scale testing to extend the state of the art is reviewed and developments in three areas are recommended as follows: (1) improve methods for simulating the engine exhaust and inlet flows; (2) develop a model support system that can simulate realistic rates of climb and descent as well as steady height operation; and (3) develop a blowing BLC ground board as an alternative to a moving belt ground board to properly simulate the flow on the ground.

Kuhn, Richard E.

1986-01-01

297

A study of high-altitude manned research aircraft employing strut-braced wings of high-aspect-ratio  

NASA Technical Reports Server (NTRS)

The effect of increased wing aspect ratio of subsonic aircraft on configurations with and without strut bracing. Results indicate that an optimum cantilever configuration, with a wing aspect ratio of approximately 26, has a 19% improvement in cruise range when compared to a baseline concept with a wing aspect ratio of approximately 10. An optimum strut braced configuration, with a wing aspect ratio of approximately 28, has a 31% improvment in cruise range when compared to the same baseline concept. This improvement is mainly due to the estimated reduction in wing weight resulting from use of lifting struts. All configurations assume the same mission payload and fuel. The drag characteristics of the wings are enhanced with the use of laminar flow airfoils. A method for determining the extent of attainable natural laminar flow, and methods for preliminary structural design and for aerodynamic analysis of wings lifting struts are presented.

Smith, P. M.; Deyoung, J.; Lovell, W. A.; Price, J. E.; Washburn, G. F.

1981-01-01

298

Multibody aircraft study, volume 1  

NASA Technical Reports Server (NTRS)

The potential benefits of a multibody aircraft when compared to a single body aircraft are presented. The analyses consist principally of a detailed point design analysis of three multibody and one single body aircraft, based on a selected payload of 350,000 kg (771,618 lb), for final aircraft definitions; sensitivity studies to evaluate the effects of variations in payload, wing semispan body locations, and fuel price; recommendations as to the research and technology requirements needed to validate the multibody concept. Two, two body, one, three body, and one single body aircraft were finalized for the selected payload, with DOC being the prime figure of merit. When compared to the single body, the multibody aircraft showed a reduction in DOC by as much as 11.3 percent. Operating weight was reduced up to 14 percent, and fly away cost reductions ranged from 8.6 to 13.4 percent. Weight reduction, hence cost, of the multibody aircraft resulted primarily from the wing bending relief afforded by the bodies being located outboard on the wing.

Moore, J. W.; Craven, E. P.; Farmer, B. T.; Honrath, J. F.; Stephens, R. E.; Bronson, C. E., Jr.; Meyer, R. T.; Hogue, J. H.

1982-01-01

299

Nocturnal aircraft noise effects.  

PubMed

Noise protection associated with the construction and extension of airports in the Federal Republic of Germany has been regulated by the law for protection against aircraft noise since 1971. This legislation is due for revision because of different aspects. One aspect is the growth of air traffic which has led many airports to the limits of their capacity and in search of new ways of adaptation to the increasing demand for flight services. Another aspect is the increasing concern of the population about noise effects which has to be addressed by better protection against the effects of aircraft noise. The framework conditions of policy in terms of society as a whole, its health and economic environment need to be put into effect by political action. Science can contribute to this goal by performing noise effects research and by providing recommendations to the political body. However, it remains controversial, what measures are necessary or adequate to assure effective protection of the population against aircraft noise. This is particularly true for the protection of rest and sleep at night. The problem of finding a common basis for adequate recommendations is associated with (1) the low number of primary studies, which also exhibited highly variable results and assessments, (2) the handling of acoustic or psycho-acoustic dimensions for quantifying psychological or physiological reactions, and (3) the conception of how far preventive measures have to go to prove effective. With this in mind, the DLR Institute for Aerospace Medicine is conducting a large-scale, multi-stage study for investigating the acute effects of nocturnal aircraft noise on human sleep. This enterprise is implemented in the framework of the HGF/DLR project "Quiet Air Traffic" for developing sustainable assessment criteria for human-specific effects of aircraft noise at night. PMID:15070533

Basner, M; Samel, A

2004-01-01

300

Aircraft Engines  

NSDL National Science Digital Library

Presented by Florida International University and NASA, this website presents a brief tutorial on the schematics for different car and aircraft engines, their cooling mechanisms, and engine development history. Here, visitors will find information on air-breathing, turboprop, turbofan, prop-fan, and ramjet engines along with handy and clear illustrations of each. This is a useful resource for educators looking for a brief, introductory handout for students in mechanical engineering and aeronautics or for students seeking material to simply illustrate the differences between engine types.

2007-07-16

301

The lift-fan aircraft: Lessons learned  

NASA Technical Reports Server (NTRS)

This report summarizes the highlights and results of a workshop held at NASA Ames Research Center in October 1992. The objective of the workshop was a thorough review of the lessons learned from past research on lift fans, and lift-fan aircraft, models, designs, and components. The scope included conceptual design studies, wind tunnel investigations, propulsion systems components, piloted simulation, flight of aircraft such as the SV-5A and SV-5B and a recent lift-fan aircraft development project. The report includes a brief summary of five technical presentations that addressed the subject The Lift-Fan Aircraft: Lessons Learned.

Deckert, Wallace H.

1995-01-01

302

Educating with Aircraft Models  

ERIC Educational Resources Information Center

Described is utilization of aircraft models, model aircraft clubs, and model aircraft magazines to promote student interest in aerospace education. The addresses for clubs and magazines are included. (SL)

Steele, Hobie

1976-01-01

303

Forecasting Aircraft Condensation Trails.  

National Technical Information Service (NTIS)

Aircraft condensation trails (contrails) are caused by aircraft aerodynamics or engine exhaust in the proper atmospheric conditions. Engine-exhaust trails are the most common and are discussed in this report. Jet aircraft contrail-formation graphs facilit...

1981-01-01

304

Human response to aircraft noise  

NASA Technical Reports Server (NTRS)

The human auditory system and the perception of sound are discussed. The major concentration is on the annnoyance response and methods for relating the physical characteristics of sound to those psychosociological attributes associated with human response. Results selected from the extensive laboratory and field research conducted on human response to aircraft noise over the past several decades are presented along with discussions of the methodology commonly used in conducting that research. Finally, some of the more common criteria, regulations, and recommended practices for the control or limitation of aircraft noise are examined in light of the research findings on human response.

Powell, Clemans A.; Fields, James M.

1991-01-01

305

Subsonic Aircraft Safety Icing Study  

NASA Technical Reports Server (NTRS)

NASA's Integrated Resilient Aircraft Control (IRAC) Project is one of four projects within the agency s Aviation Safety Program (AvSafe) in the Aeronautics Research Mission Directorate (ARMD). The IRAC Project, which was redesigned in the first half of 2007, conducts research to advance the state of the art in aircraft control design tools and techniques. A "Key Decision Point" was established for fiscal year 2007 with the following expected outcomes: document the most currently available statistical/prognostic data associated with icing for subsonic transport, summarize reports by subject matter experts in icing research on current knowledge of icing effects on control parameters and establish future requirements for icing research for subsonic transports including the appropriate alignment. This study contains: (1) statistical analyses of accident and incident data conducted by NASA researchers for this "Key Decision Point", (2) an examination of icing in other recent statistically based studies, (3) a summary of aviation safety priority lists that have been developed by various subject-matter experts, including the significance of aircraft icing research in these lists and (4) suggested future requirements for NASA icing research. The review of several studies by subject-matter experts was summarized into four high-priority icing research areas. Based on the Integrated Resilient Aircraft Control (IRAC) Project goals and objectives, the IRAC project was encouraged to conduct work in all of the high-priority icing research areas that were identified, with the exception of the developing of methods to sense and document actual icing conditions.

Jones, Sharon Monica; Reveley, Mary S.; Evans, Joni K.; Barrientos, Francesca A.

2008-01-01

306

Autonomous aircraft initiative study  

NASA Technical Reports Server (NTRS)

The results of a consulting effort to aid NASA Ames-Dryden in defining a new initiative in aircraft automation are described. The initiative described is a multi-year, multi-center technology development and flight demonstration program. The initiative features the further development of technologies in aircraft automation already being pursued at multiple NASA centers and Department of Defense (DoD) research and Development (R and D) facilities. The proposed initiative involves the development of technologies in intelligent systems, guidance, control, software development, airborne computing, navigation, communications, sensors, unmanned vehicles, and air traffic control. It involves the integration and implementation of these technologies to the extent necessary to conduct selected and incremental flight demonstrations.

Hewett, Marle D.

1991-01-01

307

Aircraft turbofan noise  

NASA Technical Reports Server (NTRS)

Turbofan noise generation and suppression in aircraft engines are reviewed. The chain of physical processes which connect unsteady flow interactions with fan blades to far field noise is addressed. Mechanism identification and description, duct propagation, radiation and acoustic suppression are discussed. The experimental technique of fan inflow static tests are discussed. Rotor blade surface pressure and wake velocity measurements aid in the determination of the types and strengths of the generation mechanisms. Approaches to predicting or measuring acoustic mode content, optimizing treatment impedance to maximize attenuation, translating impedance into porous wall structure and interpreting far field directivity patterns are illustrated by comparisons of analytical and experimental results. The interdependence of source and acoustic treatment design to minimize far field noise is emphasized. Area requiring further research are discussed and the relevance of aircraft turbofan results to quieting other turbomachinery installations is addressed.

Groeneweg, J. F.; Rice, E. J.

1983-01-01

308

Aircraft turbofan noise  

NASA Astrophysics Data System (ADS)

Turbofan noise generation and suppression in aircraft engines are reviewed. The chain of physical processes which connect unsteady flow interactions with fan blades to far field noise is addressed. Mechanism identification and description, duct propagation, radiation, and acoustic suppression are discussed. The experimental techniques of fan inflow static tests are discussed. Rotor blade surface pressure and wake velocity measurements aid in the determination of the types and strengths of the generation mechanisms. Approaches to predicting or measuring acoustic mode content, optimizing treatment impedance to maximize attenuation, translating impedance into porous wall structure, and interpreting far field directivity patterns are illustrated by comparisons of analytical and experimental results. The interdependence of source and acoustic treatment design to minimize far field noise is emphasized. Areas requiring further research are discussed, and the relevance of aircraft turbofan results to quieting other turbomachinery installation is addressed.

Groeneweg, J. F.; Rice, E. J.

1987-01-01

309

Ryan Flexwing aircraft under test  

NASA Technical Reports Server (NTRS)

A flexible wing aircraft built by Ryan, was flown in the Full Scale Tunnel. The researcher posing as the pilot is John W. Paulson, Assistant Head of the Full Scale Tunnel. Photograph published in Sixty Years of Aeronautical Research 1917-1977, by David A. Anderton - NASA publication (page 60).

1962-01-01

310

An Overview of the NASA Spring/Summer 2008 Arctic Campaign - ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites)  

NASA Technical Reports Server (NTRS)

ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) is a major NASA led airborne field campaign being performed in the spring and summer of 2008 at high latitudes (http://cloud1.arc.nasa.gov/arctas/). ARCTAS is a part of the International Polar Year program and its activities are closely coordinated with multiple U. S. (NOAA, DOE), Canadian, and European partners. Observational data from an ensemble of aircraft, surface, and satellite sensors are closely integrated with models of atmospheric chemistry and transport in this experiment. Principal NASA airborne platforms include a DC-8 for detailed atmospheric composition studies, a P-3 that focuses on aerosols and radiation, and a B-200 that is dedicated to remote sensing of aerosols. Satellite validation is a central activity in all these platforms and is mainly focused on CALIPSO, Aura, and Aqua satellites. Major ARCTAS themes are: (1) Long-range transport of pollution to the Arctic including arctic haze, tropospheric ozone, and persistent pollutants such as mercury; (2) Boreal forest fires and their implications for atmospheric composition and climate; (3) Aerosol radiative forcing from arctic haze, boreal fires, surface-deposited black carbon, and other perturbations; and (4) Chemical processes with focus on ozone, aerosols, mercury, and halogens. The spring deployment (April) is presently underway and is targeting plumes of anthropogenic and biomass burning pollution and dust from Asia and North America, arctic haze, stratosphere-troposphere exchange, and ozone photochemistry involving HOx and halogen radicals. The summer deployment (July) will target boreal forest fires and summertime photochemistry. The ARCTAS mission is providing a critical link to enhance the value of NASA satellite observations for Earth science. In this talk we will discuss the implementation of this campaign and some preliminary results.

Jacob, Daniel J.; Clarke, Antony; Crawford, James H.; Dibbs, Jack; Ferrare, Richard A.; Hostetler, Chris A.; Maring, Hal; Russell, Philip B.; Singh, Hanwant B.

2008-01-01

311

Making the Case for New Research to Support the Integration of Small Unmanned Aircraft Systems into the National Airspace System  

NASA Technical Reports Server (NTRS)

This paper describes the current state of sUAS regulation, their technical capabilities and the latest technologies that will allow for sUAS NAS integration. The research that is needed to demonstrate sUAS NAS integration capability is identified, and recommendations for conducting this necessary research are suggested.

McAdaragh, Raymon M.; Comstock, James R., Jr.; Ghatas, Rania W.; Burdette, Daniel W.; Trujillo, Anna C.

2014-01-01

312

Why aircraft fail  

Microsoft Academic Search

Failure of an aircraft structural component can have catastrophic consequences, with resultant loss of life and of the aircraft. The investigation of defects and failures in aircraft structures is, thus, of vital importance in preventing further incidents. This review discusses the common failure modes observed in aircraft structures, with examples drawn from case histories. The review will also outline the

S. J Findlay; N. D Harrison

2002-01-01

313

Aircraft lightning attachment phenomena  

NASA Technical Reports Server (NTRS)

An aircraft's influence on lightning-strike occurrence was investigated. The compression of an electric field around an aircraft was considered in mathematical calculations of an aircraft's ability to store charge. Model test results were used to predict lightning-strike attachment zones in an analysis of aircraft design.

1977-01-01

314

Aircraft. [Soviet technology  

NASA Technical Reports Server (NTRS)

The physical principles of flight, and the consideration of atmospheric composition and aerodynamic forces in the design and construction of various types of aircraft are discussed. Flight characteristics are described for helicopters, rotary-wing aircraft, short and vertical takeoff aircraft, and tailess or variable geometry wing aircraft. Flow characteristics at various speeds are also discussed.

1977-01-01

315

Aircraft Electric Secondary Power  

NASA Technical Reports Server (NTRS)

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.

1983-01-01

316

An aircraft sensor fault tolerant system  

NASA Technical Reports Server (NTRS)

The design of a sensor fault tolerant system which uses analytical redundancy for the Terminal Configured Vehicle (TCV) research aircraft in a Microwave Landing System (MLS) environment was studied. The fault tolerant system provides reliable estimates for aircraft position, velocity, and attitude in the presence of possible failures in navigation aid instruments and onboard sensors. The estimates, provided by the fault tolerant system, are used by the automated guidance and control system to land the aircraft along a prescribed path. Sensor failures are identified by utilizing the analytic relationship between the various sensor outputs arising from the aircraft equations of motion.

Caglayan, A. K.; Lancraft, R. E.

1982-01-01

317

Aircraft Emissions at Cruise and Plume Processes  

NASA Astrophysics Data System (ADS)

The detection of aircraft emissions at cruise altitudes helps to understand and assess the effects of aviation on atmospheric composition and climate. Since the early 1990s, aircraft emissions of carbon dioxide, water vapor, nitrogen and sulfur oxides, aerosol and soot and their processing in the atmosphere as well as contrail formation have been measured in situ with the instrumented DLR research aircraft Falcon. Scientific results from a series of aircraft missions are summarized and explained, uncertainties are discussed and suggestions are made on how to move forward.

Voigt, Christiane; Jurkat, Tina; Schlager, Hans; Schäuble, Dominik; Petzold, Andreas; Schumann, Ulrich

318

Partners in Freedom: Contributions of the Langley Research Center to U.S. Military Aircraft of the 1990's.  

National Technical Information Service (NTIS)

Through its history, Langley has maintained a close working partnership with the Department of Defense, U.S. industry, universities, and other government agencies to support the defense of the nation with fundamental and applied research. Many of the lege...

J. R. Chambers

2000-01-01

319

Design Methods and Optimization for Morphing Aircraft  

NASA Technical Reports Server (NTRS)

This report provides a summary of accomplishments made during this research effort. The major accomplishments are in three areas. The first is the use of a multiobjective optimization strategy to help identify potential morphing features that uses an existing aircraft sizing code to predict the weight, size and performance of several fixed-geometry aircraft that are Pareto-optimal based upon on two competing aircraft performance objectives. The second area has been titled morphing as an independent variable and formulates the sizing of a morphing aircraft as an optimization problem in which the amount of geometric morphing for various aircraft parameters are included as design variables. This second effort consumed most of the overall effort on the project. The third area involved a more detailed sizing study of a commercial transport aircraft that would incorporate a morphing wing to possibly enable transatlantic point-to-point passenger service.

Crossley, William A.

2005-01-01

320

Human factors in aircraft maintenance and inspection  

NASA Technical Reports Server (NTRS)

The events which have led to the intensive study of aircraft structural problems have contributed in no less measure to the study of human factors which influence aircraft maintenance and inspection. Initial research emphasis on aging aircraft maintenance and inspection has since broadened to include all aircraft types. Technicians must be equally adept at repairing old and new aircraft. Their skills must include the ability to repair sheet metal and composite materials; control cable and fly-by-wire systems; round dials and glass cockpits. Their work performance is heavily influenced by others such as designers, technical writers, job card authors, schedulers, and trainers. This paper describes the activities concerning aircraft and maintenance human factors.

Shepherd, William T.

1992-01-01

321

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 62: The Influence of Knowledge Diffusion on Aeronautics Innovation: The Research, Development, and Production of Large Commercial Aircraft in France, Germany, and the United Kingdom  

NASA Technical Reports Server (NTRS)

This paper focuses on how European public policies-individually and collectively - influence the diffusion of knowledge and technology. It begins with an overview of the roles played historically and currently by European governments in the Research, Development and Production (RD&P) of Large Commercial Aircraft (LCA). The analytical framework brings together literature from global political economy, comparative politics, business management, and science and technology policy studies. It distinguishes between the production of knowledge, on the one hand, and the dissemination of knowledge, on the other. France, Germany, and the United Kingdom serve as the analytical cases. The paper concludes with a call for additional research in this area, some tentative lessons learned, and a discussion of the consequences of national strategies and policies for the diffusion of knowledge and technology in an era of globalizaton.

Golich, Vicki L.; Pinelli, Thomas E.

1997-01-01

322

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 62: The Influence of Knowledge Diffusion on Aeronautics Innovation: The Research, Development, and Production of Large Commercial Aircraft in France, Germany, and the United Kingdom  

NASA Technical Reports Server (NTRS)

This paper focuses on how European public policies-individually and collectively - influence the diffusion of knowledge and technology. It begins with an overview of the roles played historically and currently by European governments in the research, development and production (RD&P) of large commercial aircraft (LCA). The analytical framework brings together literature from global political economy, comparative politics, business management, and science and technology policy studies. It distinguishes between the production of knowledge, on the one hand, and the dissemination of knowledge, on the other. France, Germany, and the United Kingdom serve as the analytical cases. The paper concludes with a call for additional research in this area, some tentative lessons learned, and a discussion of the consequences of national strategies and policies for the diffusion of knowledge and technology in an era of globalization.

Pinelli, Thomas E.; Golich, Vicki L.

1997-01-01

323

Attitude compensated electronic compass for aircraft navigation  

Microsoft Academic Search

A magnetic compass has been developed by the Research Laboratory for Avionics System of the University of Florida intended to replace the common mechanical directional gyroscope for aircraft heading indication. The compass is based on an assembly of three mutually orthogonal single-core magnetic sensors, affixed to the fuselage, thus remaining in the aircraft frame of reference. The sensor electronics incorporate

G. Basile; M. Pierantoni; S. Pirani; M. Rinaldi; S. Varosi

1994-01-01

324

Ball lightning risk to aircraft  

NASA Astrophysics Data System (ADS)

Lightning is a rare but regular phenomenon for air traffic. Aircraft are designed to withstand lightning strikes. Research on lightning and aircraft can be called detailed and effective. In the last 57 years, 18 reported lightning aviation disasters with a fatality figure of at least 714 persons occurred. For comparison, the last JACDEC ten-year average fatality figure was 857. The majority encountered lightning in the climb, descent, approach and/or landing phase. Ball lightning, a metastable, rare lightning type, is also seen from and even within aircraft, but former research only reported individual incidents and did not generate a more detailed picture to ascertain whether it constitutes a significant threat to passenger and aircraft safety. Lacking established incident report channels, observations were often only passed on as "air-travel lore". In an effort to change this unsatisfactory condition, the authors have collected a first international dataset of 38 documented ball lightning aircraft incidents from 1938 to 2001 involving 13 reports over Europe, 13 over USA/Canada, and 7 over Russia. 18 (47%) reported ball lightning outside the aircraft, 18 (47%) inside, 2 cases lacked data. 8 objects caused minor damage, 8 major damage (total: 42%), only one a crash. No damage was reported in 18 cases. 3 objects caused minor crew injury. In most cases, ball lightning lasted several seconds. 11 (29%) incidents ended with an explosion of the object. A cloud-aircraft lightning flash was seen in only 9 cases (24%) of the data set. From the detailed accounts of air personnel in the last 70 years, it is evident that ball lightning is rarely, but consistently observed in connection with aircraft and can also occur inside the airframe. Reports often came from multiple professional witnesses and in several cases, damages were investigated by civil or military authorities. Although ball lightning is no main air traffic risk, the authors suggest that incident and accident reporting is expanded and in particular damage cases are routinely assessed and published. Aircrews should know that most ball lightning-aircraft-events require thunderstorm conditions, but not necessarily a cloud-aircraft lightning flash. With nearly 50% of inside-airframe ball lightning cases, safety precautions for airline passengers should be discussed and operationalized to minimize further risk.

Doe, R.; Keul, A.

2009-04-01

325

Eclipse program QF-106 aircraft  

NASA Technical Reports Server (NTRS)

This photo shows two QF-106 aircraft that were used for the Eclipse project, both parked at the Mojave Airport in Mojave, California. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator -01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

1996-01-01

326

Small Transport Aircraft Technology  

NASA Technical Reports Server (NTRS)

The article surveys the results of the NASA-instituted Small Transport Aircraft Technology (STAT) research effort aimed at generating advanced technologies for application to new small, short haul transports having significantly better performance, efficiency, and environmental compatibility. Discussion covers fuselage designs and bonded aluminum-honeycomb wing construction which reduces the number of parts and fasteners, and gives a smoother outer contour. Topics discussed include: advanced aluminum alloys, composite primary structures, propellers, engine components, icing protection, avionics, flight controls, aerodynamics, and gust load alleviation.

Galloway, T. L.

1980-01-01

327

X-29 aircraft takeoff  

NASA Technical Reports Server (NTRS)

Two X-29 aircraft, featuring one of the most unusual designs in aviation history, were flown at the NASA Dryden Flight Research Center, Edwards, Calif., as technology demonstrators to investigate a host of advanced concepts and technologies. This movie clip runs 26 seconds and begins with a rear view of the X-29 in full afterburner at brake release, then a chase plane shot as it rotates off the runway beginning a rapid climb and finally an air-to-air view of the tail as the chase plane with the camera moves from right to left.

1989-01-01

328

Selected Directed Energy Research and Development for U.S. Air Force Aircraft Applications: A Workshop Summary.  

National Technical Information Service (NTIS)

The U.S. Air Force currently invests significantly in science and technology (S&T) for directed-energy weapon (DEW) systems. Key elements of this S&T investment include highenergy lasers (HELs) and high-power microwaves (HPMs). Other DEW research and deve...

2013-01-01

329

Innovative Materials for Aircraft Morphing  

NASA Technical Reports Server (NTRS)

Reported herein is an overview of the research being conducted within the Materials Division at NASA Langley Research Center on the development of smart material technologies for advanced airframe systems. The research is a part of the Aircraft Morphing Program which is a new six-year research program to develop smart components for self-adaptive airframe systems. The fundamental areas of materials research within the program are computational materials; advanced piezoelectric materials; advanced fiber optic sensing techniques; and fabrication of integrated composite structures. This paper presents a portion of the ongoing research in each of these areas of materials research.

Simpson, J. O.; Wise, S. A.; Bryant, R. G.; Cano, R. J.; Gates, T. S.; Hinkley, J. A.; Rogowski, R. S.; Whitley, K. S.

1997-01-01

330

Multidisciplinary Techniques and Novel Aircraft Control Systems  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

331

Multidisciplinary Techniques and Novel Aircraft Control Systems  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

332

Crafting Flight: Aircraft Pioneers and the Contributions of the Men and Women of NASA Langley Research Center  

NASA Technical Reports Server (NTRS)

While this is a self-contained history of NASA Langley Research Center's contributions to flight, many other organizations around the country played a vital role in the work described in this book.When you pass through the front gates of NASA Langley Research Center you are entering an extraordinary place. You could easily miss that fact, however. A few years cross-state bicycle tour passed through the Center. As interesting as looping around Center was, the riders observed that nothing about the vaguely industrial site fit the conventional stereotypes of what high tech looks like. NASA Langley does not fit many stereotypes. It takes a close examination to discover the many ways it has contributed to development of flight. As part of the national celebrations commemorating the 100th anniversary of the Wright brothers first flight, James Schultz, an experienced journalist with a gift for translating the language of engineers and scientists into prose that nonspecialists can comprehend, has revised and expanded Winds of Change , his wonderful guide to the Center. This revised book, Crafting Flight , invites you inside. You will read about one of the Nation s oldest research and development facilities, a place of imagination and ingenuity.

Schultz, James

2003-01-01

333

GaAs/Ge Solar Powered Aircraft  

NASA Technical Reports Server (NTRS)

Unmanned Aerial Vehicles (UAV) are being proposed for many applications for many applications including surveillance, mapping and atmospheric studies. These applications require a lightweight, low speed, medium to long duration aircraft. Due to the weight, speed, and altitude constraints imposed on such an aircraft, solar array generated electric power can be a viable alternative to air-breathing engines for certain missions. Development of such an aircraft is currently being funded under the Environmental Research Aircraft and Sensor Technology (ERAST) program. NASA Lewis Research Center (LeRC) has built a Solar Electric Airplane to demonstrate UAV technology. This aircraft utilizes high efficiency Applied Solar Energy Corporation (ASEC) GaAs/Ge space solar cells. The cells have been provided by the Air Force through the ManTech Office.

Colozza, Anthony J.; Scheiman, David A.; Brinker, David J.

1998-01-01

334

Promising Electric Aircraft Drive Systems  

NASA Technical Reports Server (NTRS)

An overview of electric aircraft propulsion technology performance thresholds for key power system components is presented. A weight comparison of electric drive systems with equivalent total delivered energy is made to help identify component performance requirements, and promising research and development opportunities.

Dudley, Michael R.

2010-01-01

335

Commercial aircraft fuel efficiency potential through 2010  

SciTech Connect

Aircraft are second only to motor vehicles in the use of motor fuels, and air travel is growing twice as fast. Since 1970 air travel has more than tripled, but the growth of fuel use has been restrained by a near doubling of efficiency, from 26.2 seat miles per gallon (SMPG) in 1970 to about 49 SMPG in 1989. This paper explores the potential for future efficiency improvements via the replacement of existing aircraft with 1990's generation'' and post 2000'' aircraft incorporating advances in engine and airframe technology. Today, new commercial passenger aircraft deliver 50--70 SMPG. New aircraft types scheduled for delivery in the early 1990's are expected to achieve 65--80 SMPG. Industry and government researchers have identified technologies capable of boosting aircraft efficiencies to the 100--150 SMPG range. Under current industry plans, which do not include a post-2000 generation of new aircraft, the total aircraft fleet should reach the vicinity of 65 SMPG by 2010. A new generation of 100--150 SMPG aircraft introduced in 2005 could raise the fleet average efficiency to 75--80 SMPG in 2010. In any case, fuel use will likely continue to grow at from 1--2%/yr. through 2010. 20 refs., 2 figs., 2 tabs.

Greene, D.L.

1990-01-01

336

Propulsion controlled aircraft computer  

NASA Technical Reports Server (NTRS)

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.

Cogan, Bruce R. (Inventor)

2010-01-01

337

V/STOL aircraft concepts  

NASA Technical Reports Server (NTRS)

The Potential for V/STOL Aircraft Concepts for Air Transportation in the CALIFORNIA CORRIDOR in the 2010 time period is projected. The project description is to study the potential for V/STOL aircraft concepts in air transportation within the California Corridor, and emphasize V/STOL configurations that are innovative and unconventional in design for use in the 2010 time period. The project is consistent with the mission of the NASA/Ames Research Center and succeeding classes at Cal Poly can iterate and refine for meaningful results for NASA.

1987-01-01

338

Altus aircraft on runway  

NASA Technical Reports Server (NTRS)

The remotely piloted Altus aircraft flew several developmental test flights from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif., in 1996. The Altus--the word is Latin for 'high'--is a variant of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. It is designed for high-altitude, long-duration scientific sampling missions, and is powered by a turbocharged four-cylinder piston engine. The first Altus was developed under NASA's Environmental Research Aircraft and Sensor Technology program, while a second Altus was built for a Naval Postgraduate School/Department of Energy program. A pilot in a control station on the ground flew the craft by radio signals, using visual cues from a video camera in the nose of the Altus and information from the craft's air data system. Equipped with a single-stage turbocharger during the 1996 test flights, the first Altus reached altitudes in the 37,000-foot range, while the similarly-equipped second Altus reached 43,500 feet during developmental flights at Dryden in the summer of 1997. The NASA Altus also set an endurance record of more than 26 hours while flying a science mission in late 1996 and still had an estimated 10 hours of fuel remaining when it landed. Now equipped with a two-stage turbocharger, the NASA Altus maintained an altitude of 55,000 feet for four hours during flight tests in 1999.

1996-01-01

339

Real-time flutter analysis of an active flutter-suppression system on a remotely piloted research aircraft  

NASA Technical Reports Server (NTRS)

Flight-test results of the first three flights of an aeroelastic research wing are described. The flight flutter-test technique used to obtain real-time damping estimates from fast-frequency sweep data was obtained and the open-loop flutter boundary determined. Nyquist analyses of sweep maneuvers appear to provide additional valuable information about flutter suppression system operation, both in terms of phase-margin estimates and as a means of evaluating maneuver quality. An error in implementing the flutter-suppression system required in a one-half nominal gain configuration, which caused the wing to be unstable at lower Mach numbers than anticipated, and the vehicle experienced closed-loop flutter on its third flight. Real-time flutter-testing procedures were improved.

Gilyard, G. B.; Edwards, J. W.

1983-01-01

340

Dynamic properties of aircraft tires  

NASA Technical Reports Server (NTRS)

A research program has investigated the use of the von Schlippe string-type tire model for predicting the dynamic behavior of aircraft tires. The transfer-function method was used for theory evaluation. A more flexible two-constant modification to the string theory tire model is presented. Experiments were conducted on four types of scale model aircraft tires. Two types were of conventional bias construction, one type was an isotropic toroid, and one type was of unbelted radial construction. The conventional string theory and model gave predictions that were in good agreement with experimental data for bias constructed tires. The two-constant modification to string theory provided better agreement between predictions and experiment for the unconventional tires. The results indicate that the string theory tire model using static and slow-rolling tire properties predicts dynamic aircraft tire properties that have the same trends as the measured dynamic properties and, in most cases, provides good quantitative agreement.

Clark, S. K.; Dodge, R. N.; Nybakken, G. H.

1974-01-01

341

Steering Aircraft Clear of Choppy Air  

NASA Technical Reports Server (NTRS)

AeroTech Research (U.S.A.), Inc., a leader in turbulence-detection and warning systems, has been involved with NASA Aviation Safety research since 1998. AeroTech served as a contractor for the TPAWS government/industry development project, and was funded by NASA to develop the E-Turb Mode Radar algorithms and the TAPS software. (Other contributors to this project include the National Center for Atmospheric Research, the FAA, North Carolina State University, and the Research Triangle Institute.) The radar algorithms combine an aircraft's turbulenceresponse characteristics with radar measurements to determine the predicted turbulence loads the aircraft will experience, and present this information to the pilot. The TAPS software monitors and processes onboard aircraft sensor data; generates automatic reports when an aircraft encounters turbulence and a set turbulence threshold is exceeded; and then displays the reports and underlying information to ground personnel to improve situational awareness of the location and the severity of the turbulence encounter.

2006-01-01

342

Adaptive Flight Control for Aircraft Safety Enhancements.  

National Technical Information Service (NTIS)

This poster presents the current adaptive control research being conducted at NASA ARC and LaRC in support of the Integrated Resilient Aircraft Control (IRAC) project. The technique 'Approximate Stability Margin Analysis of Hybrid Direct-Indirect Adaptive...

I. M. Gregory N. T. Nguyen S. M. Joshi

2008-01-01

343

AIRCRAFT DEPAINTING TECHNOLOGY  

EPA Science Inventory

Chemical paint strippers historically used for aircraft contained toxic and hazardous components; aircraft depainting operations are a major source of hazardous waste generation in DOD. Federal and state agencies have begun to restrict using these hazardous materials and Governme...

344

Aircraft Hydraulic Servomechanisms.  

National Technical Information Service (NTIS)

The authors have attempted to present to others concerned with the analysis, design, and testing of integrated aircraft control systems, certain fundamental information regarding the hydraulic servomechanisms used to position the aircraft control surfaces...

I. L. Ashkenas G. E. Click D. Graham J. W. Hager A. P. Henry

1969-01-01

345

Aircraft type influence on contrail properties  

NASA Astrophysics Data System (ADS)

The investigation of the impact of aircraft parameters on contrail properties helps to better understand the climate impact from aviation. Yet, in observations, it is a challenge to separate aircraft and meteorological influences on contrail formation. During the CONCERT campaign in November 2008, contrails from 3 Airbus passenger aircraft of type A319-111, A340-311 and A380-841 were probed at cruise under similar meteorological conditions with in-situ instruments on board the DLR research aircraft Falcon. Within the 2 min old contrails detected near ice saturation, we find similar effective diameters Deff (5.2-5.9 ?m), but differences in particle number densities nice (162-235 cm-3) and in vertical contrail extensions (120-290 m), resulting in large differences in contrail optical depths ? (0.25-0.94). Hence larger aircraft produce optically thicker contrails. Based on the observations, we apply the EULAG-LCM model with explicit ice microphysics and in addition the Contrail and Cirrus Prediction model CoCiP to calculate the aircraft type impact on young contrails under identical meteorological conditions. The observed increase in ? for heavier aircraft is confirmed by the models, yet for generally smaller ?. An aircraft dependence of climate relevant contrail properties persists during contrail lifetime, adding importance to aircraft dependent model initialization. We finally derive an analytical relationship between contrail, aircraft and meteorological parameters. Near ice saturation, contrail width × ? scales linearly with fuel flow rate as confirmed by observations. For higher saturation ratios approximations from theory suggest a non-linear increase in the form (RHI-1)2/3. Summarized our combined results could help to more accurately assess the climate impact from aviation using an aircraft dependent contrail parameterization.

Jeßberger, P.; Voigt, C.; Schumann, U.; Sölch, I.; Schlager, H.; Kaufmann, S.; Petzold, A.; Schäuble, D.; Gayet, J.-F.

2013-05-01

346

Aircraft Lightning Electromagnetic Environment Measurement  

NASA Technical Reports Server (NTRS)

This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect.

Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.

2011-01-01

347

Discussion of Approaches to Estimate the Aircraft Stopping Distances Under Standard Operating Procedures.  

National Technical Information Service (NTIS)

The Federal Aviation Administration is currently engaged in research of aircraft operational landing performance, aiming to increase the safety and efficiency of aircraft operations in terminal areas. One of the primary research objectives was to identify...

A. Cheng

2007-01-01

348

Probing Aircraft Flight Test Hazard Mitigation for the Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) Research Team . Volume 2; Appendices  

NASA Technical Reports Server (NTRS)

The Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) Project Integration Manager requested in July 2012 that the NASA Engineering and Safety Center (NESC) form a team to independently assess aircraft structural failure hazards associated with the ACCESS experiment and to identify potential flight test hazard mitigations to ensure flight safety. The ACCESS Project Integration Manager subsequently requested that the assessment scope be focused predominantly on structural failure risks to the aircraft empennage (horizontal and vertical tail). This report contains the Appendices to Volume I.

Kelly, Michael J.

2013-01-01

349

Review of factors affecting aircraft wet runway performance  

NASA Technical Reports Server (NTRS)

Problems associated with aircraft operations on wet runways are discussed and major factors which influence tire/runway braking and cornering traction capability are identified including runway characteristics, tire hydroplaning, brake system anomalies, and pilot inputs. Research results from investigations conducted at the Langley Aircraft Landing Loads and Traction Facility and from tests with instrumented ground vehicles and aircraft are summarized to indicate the effects of different aircraft, tire, and runway parameters. Several promising means are described for improving tire/runway water drainage capability, brake system efficiency, and pilot training to help optimize aircraft traction performance on wet runways.

Yager, T. J.

1983-01-01

350

Future aircraft networks and schedules  

NASA Astrophysics Data System (ADS)

Because of the importance of air transportation scheduling, the emergence of small aircraft and the vision of future fuel-efficient aircraft, this thesis has focused on the study of aircraft scheduling and network design involving multiple types of aircraft and flight services. It develops models and solution algorithms for the schedule design problem and analyzes the computational results. First, based on the current development of small aircraft and on-demand flight services, this thesis expands a business model for integrating on-demand flight services with the traditional scheduled flight services. This thesis proposes a three-step approach to the design of aircraft schedules and networks from scratch under the model. In the first step, both a frequency assignment model for scheduled flights that incorporates a passenger path choice model and a frequency assignment model for on-demand flights that incorporates a passenger mode choice model are created. In the second step, a rough fleet assignment model that determines a set of flight legs, each of which is assigned an aircraft type and a rough departure time is constructed. In the third step, a timetable model that determines an exact departure time for each flight leg is developed. Based on the models proposed in the three steps, this thesis creates schedule design instances that involve almost all the major airports and markets in the United States. The instances of the frequency assignment model created in this thesis are large-scale non-convex mixed-integer programming problems, and this dissertation develops an overall network structure and proposes iterative algorithms for solving these instances. The instances of both the rough fleet assignment model and the timetable model created in this thesis are large-scale mixed-integer programming problems, and this dissertation develops subproblem schemes for solving these instances. Based on these solution algorithms, this dissertation also presents computational results of these large-scale instances. To validate the models and solution algorithms developed, this thesis also compares the daily flight schedules that it designs with the schedules of the existing airlines. Furthermore, it creates instances that represent different economic and fuel-prices conditions and derives schedules under these different conditions. In addition, it discusses the implication of using new aircraft in the future flight schedules. Finally, future research in three areas---model, computational method, and simulation for validation---is proposed.

Shu, Yan

351

Aircraft Carrier Exposure Testing of Aircraft Materials.  

National Technical Information Service (NTIS)

Previous studies have demonstrated that the aircraft carrier environment in the western Pacific Ocean is far more severe than other marine or industrial environments. Laboratory accelerated tests do not necessarily reproduce the real time corrosion behavi...

E. W. Lee N. Abourialy J. Kozol

2004-01-01

352

Remotely piloted aircraft in the civil environment  

NASA Technical Reports Server (NTRS)

Improved remotely piloted aircraft (RPAs), i.e., incorporating reductions in size, weight, and cost, are becoming available for civilian applications. Existing RPA programs are described and predicted into the future. Attention is given to the NASA Mini-Sniffer, which will fly to altitudes of more than 20,000 m, sample the atmosphere behind supersonic cruise aircraft, and telemeter the data to ground stations. Design and operating parameters of the aircraft are given, especially the optical sensing systems, and civilian RPA uses are outlined, including airborne research, remote mapping, rescue, message relay, and transportation of need materials. Civil regulatory factors are also dealt with.

Gregory, T. J.; Nelms, W. P.; Karmarkar, J. S.

1977-01-01

353

Aircraft control in wake vortex wind shear  

NASA Technical Reports Server (NTRS)

In the past, there have been a number of fatal incidents attributable to wake vortex encounters, involving both general aviation and commercial aircraft. In fact, the wake vortex hazard is considered to be the single dominant safety issue determining the aircraft spacing requirements at airports. As the amount of air traffic increases, the number of dangerous encounters is likely only to increase. It is therefore imperative that a means be found to reduce the danger. That is the purpose of this research: to use nonlinear inverse dynamic (NID) control methods in the design of an aircraft control system which can improve the safety margin in a wake vortex encounter.

Wold, Gregory R.

1995-01-01

354

Laser Powered Aircraft Takes Flight  

NASA Technical Reports Server (NTRS)

A team of NASA researchers from Marshall Space Flight Center (MSFC) and Dryden Flight Research center have proven that beamed light can be used to power an aircraft, a first-in-the-world accomplishment to the best of their knowledge. Using an experimental custom built radio-controlled model aircraft, the team has demonstrated a system that beams enough light energy from the ground to power the propeller of an aircraft and sustain it in flight. Special photovoltaic arrays on the plane, similar to solar cells, receive the light energy and convert it to electric current to drive the propeller motor. In a series of indoor flights this week at MSFC, a lightweight custom built laser beam was aimed at the airplane `s solar panels. The laser tracks the plane, maintaining power on its cells until the end of the flight when the laser is turned off and the airplane glides to a landing. The laser source demonstration represents the capability to beam more power to a plane so that it can reach higher altitudes and have a greater flight range without having to carry fuel or batteries, enabling an indefinite flight time. The demonstration was a collaborative effort between the Dryden Center at Edward's, California, where the aircraft was designed and built, and MSFC, where integration and testing of the laser and photovoltaic cells was done. Laser power beaming is a promising technology for consideration in new aircraft design and operation, and supports NASA's goals in the development of revolutionary aerospace technologies. Photographed with their invention are (from left to right): David Bushman and Tony Frackowiak, both of Dryden; and MSFC's Robert Burdine.

2003-01-01

355

Inflight characterization of aircraft icing  

NASA Astrophysics Data System (ADS)

This thesis advances the development of the Ice Management System (IMS), which has been previously proposed as an additional layer of safety against aircraft icing accidents, by presenting and validating a conceptual design for the icing characterization function of the IMS. This icing characterization function seeks to provide a near real-time estimate of the degradation of the aircraft flight dynamics due to icing. The icing characterization is extracted from various information sources comprising Hinfinity parameter identification of the flight dynamics, steady-state characterization of the aircraft trim, aerodynamic hinge moment sensing, and an estimate of the flight-dynamics excitation. Two aspects of the icing characterization are novel: (i) real-time Hinfinity parameter identification of the flight dynamics, and (ii) preprocessing and assimilation of the various measurements that individually provide partial information on the icing degradation into a single comprehensive icing characterization, the so-called sensor fusion function. These two aspects of the icing characterization are validated by applying them in computer simulation to a rich set of flight scenarios. Moreover, the Hinfinity parameter identification is applied successfully to flight-test data generated by the NASA Twin Otter icing research aircraft, and validated against an existing flight-dynamics identification technique. Finally, consideration of an independent icing degradation estimate from atmospheric and photographic measurements demonstrates that the H infinity parameter estimate provides an indication of icing degradation for a natural-icing flight test.

Melody, James William

356

High altitude reconnaissance aircraft design  

NASA Technical Reports Server (NTRS)

A Universities Space Research Association (USRA) sponsored (undergraduate) study is presented on the feasibility and design of a high altitude reconnaissance/research aircraft. The aircraft mission was to carry 1,000-3,000 lb of atmospheric pollutant monitoring equipment for 1-5 hr at an altitude of 100,000-130,000 ft. Three configurations subject to the same mission requirements were studied in detail. The three designs analyzed were the tandem-wing-twin-boom, joined wing, and conventional twin-boom configurations. The performance of the three proposed configurations is presented and shows that high altitude flight is possible with current technology. Different possible propulsion systems were investigated and suggestions are made for further investigation and better optimization of the designs.

Poladian, D.; Reinhard, D. J.

1989-01-01

357

Aircraft Lightning Initiation and Interception From In Situ Electric Measurements and Fast Video Observations  

Microsoft Academic Search

Multipoint electric field measurements on the French C-160 research airplane presented additional verification for a physical model of aircraft-triggered lightning as a bidirectional leader initiated on the aircraft. For the few lightning strikes to aircraft that were not aircraft-triggered, the multipoint electric field measurements proved that these strikes resulted from interception of the aircraft by natural lightning flashes. Video images

Jean-Patrick Moreau; Jean-Claude Alliot; Vladislav Mazur

1992-01-01

358

Daedalus Project's Light Eagle - Human powered aircraft  

NASA Technical Reports Server (NTRS)

The Michelob Light Eagle is seen here in flight over Rogers Dry Lake at the NASA Dryden Flight Research Center, Edwards, California. The Light Eagle and Daedalus human powered aircraft were testbeds for flight research conducted at Dryden between January 1987 and March 1988. These unique aircraft were designed and constructed by a group of students, professors, and alumni of the Massachusetts Institute of Technology within the context of the Daedalus project. The construction of the Light Eagle and Daedalus aircraft was funded primarily by the Anheuser Busch and United Technologies Corporations, respectively, with additional support from the Smithsonian Air and Space Museum, MIT, and a number of other sponsors. To celebrate the Greek myth of Daedalus, the man who constructed wings of wax and feathers to escape King Minos, the Daedalus project began with the goal of designing, building and testing a human-powered aircraft that could fly the mythical distance, 115 km. To achieve this goal, three aircraft were constructed. The Light Eagle was the prototype aircraft, weighing 92 pounds. On January 22, 1987, it set a closed course distance record of 59 km, which still stands. Also in January of 1987, the Light Eagle was powered by Lois McCallin to set the straight distance, the distance around a closed circuit, and the duration world records for the female division in human powered vehicles. Following this success, two more aircraft were built, the Daedalus 87 and Daedalus 88. Each aircraft weighed approximately 69 pounds. The Daedalus 88 aircraft was the ship that flew the 199 km from the Iraklion Air Force Base on Crete in the Mediterranean Sea, to the island of Santorini in 3 hours, 54 minutes. In the process, the aircraft set new records in distance and endurance for a human powered aircraft. The specific areas of flight research conducted at Dryden included characterizing the rigid body and flexible dynamics of the Light Eagle, investigating sensors for an autopilot that could be used on high altitude or human powered aircraft, and determining the power required to fly the Daedalus aircraft. The research flights began in late December 1987 with a shake-down of the Light Eagle instrumentation and data transfer links. The first flight of the Daedalus 87 also occurred during this time. On February 7, 1988, the Daedalus 87 aircraft crashed on Rogers Dry Lakebed. The Daedalus 88, which later set the world record, was then shipped from MIT to replace the 87's research flights, and for general checkout procedures. Due to the accident, flight testing was extended four weeks and thus ended in mid-March 1988 after having achieved the major goals of the program; exploring the dynamics of low Reynolds number aircraft, and investigating the aeroelastic behavior of lightweight aircraft. The information obtained from this program had direct applications to the later design of many high-altitude, long endurance aircraft.

1987-01-01

359

Raptors and aircraft  

USGS Publications Warehouse

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.

Smith, D.G.; Ellis, D.H.; Johnson, T.H.

1988-01-01

360

Lightning effects on aircraft  

NASA Technical Reports Server (NTRS)

Direct and indirect effects of lightning on aircraft were examined in relation to aircraft design. Specific trends in design leading to more frequent lightning strikes were individually investigated. These trends included the increasing use of miniaturized, solid state components in aircraft electronics and electric power systems. A second trend studied was the increasing use of reinforced plastics and other nonconducting materials in place of aluminum skins, a practice that reduces the electromagnetic shielding furnished by a conductive skin.

1977-01-01

361

Tilt Rotor Aircraft Aeroacoustics  

NASA Technical Reports Server (NTRS)

A fleet of civil tilt rotor transports offers a means of reducing airport congestion and point-to-point travel time. The speed, range, and fuel economy of these aircraft, along with their efficient use of vertiport area, make them good candidates for short-to-medium range civil transport. However, to be successfully integrated into the civilian community, the tilt rotor must be perceived as a quiet, safe, and economical mode of transportation that does not harm the environment. In particular, noise impact has been identified as a possible barrier to the civil tilt rotor. Along with rotor conversion-mode flight, and blade-vortex interaction noise during descent, hover mode is a noise problem for tilt rotor operations. In the present research, tilt rotor hover aeroacoustics have been studied analytically, experimentally, and computationally. Various papers on the subject were published as noted in the list of publications. More recently, experimental measurements were made on a 1/12.5 scale model of the XV-15 in hover and analyses of this data and extrapolations to full scale were also carried out. A dimensional analysis showed that the model was a good aeroacoustic approximation to the full-scale aircraft, and scale factors were derived to extrapolate the model measurements to the full-scale XV-15. The experimental measurements included helium bubble flow visualization, silk tuft flow visualization, 2-component hot wire anemometry, 7-hole pressure probe measurements, vorticity measurements, and outdoor far field acoustic measurements. The hot wire measurements were used to estimate the turbulence statistics of the flow field into the rotors, such as length scales, velocity scales, dissipation, and turbulence intermittency. Several different configurations of the model were tested: (1) standard configurations (single isolated rotor, two rotors without the aircraft, standard tilt rotor configuration); (2) flow control devices (the 'plate', the 'diagonal fences'); (3) basic configuration changes (increasing the rotor/rotor spacing, reducing the rotor plane/wing clearance. operating the rotors out of phase). Also, an approximation to Sikorsky's Variable Diameter Tilt Rotor (VDTR) configuration was tested, and some flow measurements were made on a semi-span configuration of the model. Acoustic predictions were made using LOWSON.M, a Mathematica code Mean aerodynamic models were developed based on hover performance predictions from HOVER.FOR. This hover prediction code used blade element theory for the aerodynamics, and Prandtl's Vortex theory to model the wake, along with empirical formulas for the effects of Reynolds number, Mach number, and stall. Aerodynamic models were developed from 7-hole pressure probe measurements of the mean velocity into the model rotors.

George, Albert R.

1996-01-01

362

Vision-based aircraft guidance  

NASA Technical Reports Server (NTRS)

Early research on the development of machine vision algorithms to serve as pilot aids in aircraft flight operations is discussed. The research is useful for synthesizing new cockpit instrumentation that can enhance flight safety and efficiency. With the present work as the basis, future research will produce low-cost instrument by integrating a conventional TV camera together with off-the=shelf digitizing hardware for flight test verification. Initial focus of the research will be on developing pilot aids for clear-night operations. Latter part of the research will examine synthetic vision issues for poor visibility flight operations. Both research efforts will contribute towards the high-speed civil transport aircraft program. It is anticipated that the research reported here will also produce pilot aids for conducting helicopter flight operations during emergency search and rescue. The primary emphasis of the present research effort is on near-term, flight demonstrable technologies. This report discusses pilot aids for night landing and takeoff and synthetic vision as an aid to low visibility landing.

Menon, P. K.

1993-01-01

363

Some fighter aircraft trends  

NASA Technical Reports Server (NTRS)

Some basic trends in fighter aircraft are traced from the post World War II era. Beginning with the first operational jet fighter, the P-80, the characteristics of subsequent fighter aircraft are examined in terms of performance, mission capability, effectiveness, and cost. Characteristics presented include such items as power loading, wing loading, maximum speed, rate of climb, turn rate, weight and weight distribution, cost and cost distribution. In some cases, the characteristics of U.S.S.R. aircraft are included for comparison. The trends indicate some of the rationale for certain fighter designs and indicate some likely characteristics to be sought in future fighter aircraft designs.

Spearman, M. L.

1984-01-01

364

Conditions Conducive to Lightning Striking an Aircraft in a Thunderstorm.  

National Technical Information Service (NTIS)

The UHF band radar at NASA/Wallops Island Research Facility was used for guiding the NASA F106 research aircraft through the upper regions of storms with lightning activity in them so that the aircraft would be struck by lightning. The radar was used also...

V. Mazur, B. D. Fisher, J. C. Gerlach

1983-01-01

365

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 59: Japanese Technological Innovation. Implications for Large Commercial Aircraft and Knowledge Diffusion  

NASA Technical Reports Server (NTRS)

This paper explores three factors-public policy, the Japanese (national) innovation system, and knowledge-that influence technological innovation in Japan. To establish a context for the paper, we examine Japanese culture and the U.S. and Japanese patent systems in the background section. A brief history of the Japanese aircraft industry as a source of knowledge and technology for other industries is presented. Japanese and U.S. alliances and linkages in three sectors-biotechnology, semiconductors, and large commercial aircraft (LCA)-and the importation, absorption, and diffusion of knowledge and technology are examined next. The paper closes with implications for diffusing knowledge and technology, U.S. public policy, and LCA.

Pinelli, Thomas E.; Barclay, Rebecca O.; Kotler, Mindy L.

1997-01-01

366

Terminal area automatic navigation, guidance, and control research using the Microwave Landing System (MLS). Part 2: RNAV/MLS transition problems for aircraft  

NASA Technical Reports Server (NTRS)

The problems in navigation and guidance encountered by aircraft in the initial transition period in changing from distance measuring equipment, VORTAC, and barometric instruments to the more precise microwave landing system data type navaids in the terminal area are investigated. The effects of the resulting discontinuities on the estimates of position and velocity for both optimal (Kalman type navigation schemes) and fixed gain (complementary type) navigation filters, and the effects of the errors in cross track, track angle, and altitude on the guidance equation and control commands during the critical landing phase are discussed. A method is presented to remove the discontinuities from the navigation loop and to reconstruct an RNAV path designed to land the aircraft with minimal turns and altitude changes.

Pines, S.

1982-01-01

367

Modeling Programs Increase Aircraft Design Safety  

NASA Technical Reports Server (NTRS)

Flutter may sound like a benign word when associated with a flag in a breeze, a butterfly, or seaweed in an ocean current. When used in the context of aerodynamics, however, it describes a highly dangerous, potentially deadly condition. Consider the case of the Lockheed L-188 Electra Turboprop, an airliner that first took to the skies in 1957. Two years later, an Electra plummeted to the ground en route from Houston to Dallas. Within another year, a second Electra crashed. In both cases, all crew and passengers died. Lockheed engineers were at a loss as to why the planes wings were tearing off in midair. For an answer, the company turned to NASA s Transonic Dynamics Tunnel (TDT) at Langley Research Center. At the time, the newly renovated wind tunnel offered engineers the capability of testing aeroelastic qualities in aircraft flying at transonic speeds near or just below the speed of sound. (Aeroelasticity is the interaction between aerodynamic forces and the structural dynamics of an aircraft or other structure.) Through round-the-clock testing in the TDT, NASA and industry researchers discovered the cause: flutter. Flutter occurs when aerodynamic forces acting on a wing cause it to vibrate. As the aircraft moves faster, certain conditions can cause that vibration to multiply and feed off itself, building to greater amplitudes until the flutter causes severe damage or even the destruction of the aircraft. Flutter can impact other structures as well. Famous film footage of the Tacoma Narrows Bridge in Washington in 1940 shows the main span of the bridge collapsing after strong winds generated powerful flutter forces. In the Electra s case, faulty engine mounts allowed a type of flutter known as whirl flutter, generated by the spinning propellers, to transfer to the wings, causing them to vibrate violently enough to tear off. Thanks to the NASA testing, Lockheed was able to correct the Electra s design flaws that led to the flutter conditions and return the aircraft to safe flight. Today, all aircraft must have a flutter boundary 15 percent beyond the aircraft s expected maximum speed to ensure that flutter conditions are not encountered in flight. NASA continues to support research in new aircraft designs to improve knowledge of aeroelasticity and flutter. Through platforms such as Dryden Flight Research Center s Active Aeroelastic Wing (AAW) research aircraft, the Agency researches methods for in-flight validation of predictions and for controlling and taking advantage of aeroelastic conditions to enhance aircraft performance.

2012-01-01

368

RETROGRESSION AND RE-AGING (RRA) OF ALUMINUM 7075-T6 AIRCRAFT COMPONENTS D. Peeler Air Force Research Laboratory Materials and Manufacturing Directorate  

Microsoft Academic Search

Stress corrosion cracking (SCC) of primary structural components manufactured from Al 7075-T6 forgings, extrusions and plate products continues to plague aging aircraft. A two-step heat treatment, Retrogression and Re-aging (RRA), applied to 7XXX series aluminum alloys in the T6 temper has been shown to greatly enhance the SCC resistance of these materials with minimal tradeoff in strength. The RRA technology

D. Raizenne; P. Sjöblom; R. Rondeau; S. Kuhlman; J. Snide

369

Aircraft Optimization for Minimum Environmental Impact  

NASA Technical Reports Server (NTRS)

The objective of this research is to investigate the tradeoff between operating cost and environmental acceptability of commercial aircraft. This involves optimizing the aircraft design and mission to minimize operating cost while constraining exterior noise and emissions. Growth in air traffic and airport neighboring communities has resulted in increased pressure to severely penalize airlines that do not meet strict local noise and emissions requirements. As a result, environmental concerns have become potent driving forces in commercial aviation. Traditionally, aircraft have been first designed to meet performance and cost goals, and adjusted to satisfy the environmental requirements at given airports. The focus of the present study is to determine the feasibility of including noise and emissions constraints in the early design of the aircraft and mission. This paper introduces the design tool and results from a case study involving a 250-passenger airliner.

Antoine, Nicolas; Kroo, Ilan M.

2001-01-01

370

Unmanned reconnaissance aircraft, Predator B in flight.  

NASA Technical Reports Server (NTRS)

Predator B unmanned reconnaissance aircraft, shown here, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. ALTAIR/PREDATOR B -- General Atomics Aeronautical Systems, Inc., is developing the Altair version of its Predator B unmanned reconnaissance aircraft, shown here, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. NASA plans to use the Altair as a technology demonstrator testbed aircraft to validate a variety of command and control technologies for unmanned aerial vehicles (UAV), as well as demonstrate the capability to perform a variety of Earth science missions. The Altair is designed to carry an 700-lb. payload of scientific instruments and imaging equipment for as long as 32 hours at up to 52,000 feet altitude. Ten-foot extensions have been added to each wing, giving the Altair an overall wingspan of 84 feet with an aspect ratio of 23. It is powered by a 700-hp. rear-mounted TPE-331-10 turboprop engine, driving a three-blade propeller. Altair is scheduled to begin flight tests in the fourth quarter of 2002, and be acquired by NASA following successful completion of those basic airworthiness tests in early 2003 for evaluation of over-the-horizon control, detect, see and avoid and other technologies required to allow UAVs to operate safely with other aircraft in the national airspace.

2001-01-01

371

Lightning protection of aircraft  

NASA Technical Reports Server (NTRS)

The current knowledge concerning potential lightning effects on aircraft and the means that are available to designers and operators to protect against these effects are summarized. The increased use of nonmetallic materials in the structure of aircraft and the constant trend toward using electronic equipment to handle flight-critical control and navigation functions have served as impetus for this study.

Fisher, F. A.; Plumer, J. A.

1977-01-01

372

IDENTIFICATION OF AIRCRAFT HAZARDS  

Microsoft Academic Search

Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of

K. L. Ashley

2005-01-01

373

Solar Thermal Aircraft.  

National Technical Information Service (NTIS)

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in t...

C. L. Bennett

2004-01-01

374

Aircraft EMP isolation study  

NASA Astrophysics Data System (ADS)

This report presents the results of a preliminary study into methods for electrically isolating the E-4B, the EC-135, and the EC-130 aircraft during EMP tests where the aircraft under test is directly driven by a high-voltage pulser.

Finci, A.; Price, H.; Chao, P.; Mercer, S.; Naff, T.

1980-07-01

375

Civil aircraft accident investigation.  

PubMed

This talk reviews some historic aircraft accidents and some more recent. It reflects on the division of accident causes, considering mechanical failures and aircrew failures, and on aircrew training. Investigation results may lead to improved aircraft design, and to appropriate crew training. PMID:24057309

Haines, Daniel

2013-01-01

376

Cable Tensiometer for Aircraft  

NASA Technical Reports Server (NTRS)

The invention is a cable tensiometer that can be used on aircraft for real-time, in-flight cable tension measurements. The invention can be used on any aircraft cables with high precision. The invention is extremely light-weight, hangs on the cable being tested and uses a dual bending beam design with a high mill-volt output to determine tension.

Nunnelee, Mark (Inventor)

2008-01-01

377

B-52 Launch Aircraft in Flight  

NASA Technical Reports Server (NTRS)

NASA's venerable B-52 mothership is seen here photographed from a KC-135 Tanker aircraft. The X-43 adapter is visible attached to the right wing. The B-52, used for launching experimental aircraft and for other flight research projects, has been a familiar sight in the skies over Edwards for more than 40 years and is also both the oldest B-52 still flying and the aircraft with the lowest flight time of any B-52. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most significant research projects in aerospace history. Some of the significant projects supported by B-52 008 include the X-15, the lifting bodies, HiMAT (highly maneuverable aircraft technology), Pegasus, validation of parachute systems developed for the space shuttle program (solid-rocket-booster recovery system and the orbiter drag chute system), and the X-38. The B-52 served as the launch vehicle on 106 X-15 flights and flew a total of 159 captive-carry and launch missions in support of that program from June 1959 to October 1968. Information gained from the highly successful X-15 program contributed to the Mercury, Gemini, and Apollo human spaceflight programs as well as space shuttle development. Between 1966 and 1975, the B-52 served as the launch aircraft for 127 of the 144 wingless lifting body flights. In the 1970s and 1980s, the B-52 was the launch aircraft for several aircraft at what is now the Dryden Flight Research Center, Edwards, California, to study spin-stall, high-angle-of attack, and maneuvering characteristics. These included the 3/8-scale F-15/spin research vehicle (SRV), the HiMAT (Highly Maneuverable Aircraft Technology) research vehicle, and the DAST (drones for aerodynamic and structural testing). The aircraft supported the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet.

2001-01-01

378

Fluidic emergency thruster for aircraft  

NASA Technical Reports Server (NTRS)

The design, development, fabrication and test evaluation of two prototype fluidic emergency thrusters (FET) for aircraft stabilization are discussed. The fluidic control units were designed to provide, between two diametrically opposed nozzles, a thrust differential proportional to an input voltage signal. The emergency roll control requirements of the X-14 VTOL research aircraft were defined as typical design goals. Two control units, one on each wing tip, are intended to provide a maximum thrust of 224 pounds per unit. The units are designed to operate with 2500 psig, 2000 F gas from a solid propellant gas generator. The emergency system including the gas generator was designed to add less than 11 pounds per wing tip. The operating time under emergency conditions was specified as five seconds. The fluidic emergency thruster is similar in concept to a JATO system but has the added feature of controllable thrust.

Honda, T. S.

1972-01-01

379

CID Aircraft slap-down  

NASA Technical Reports Server (NTRS)

In this photograph the B-720 is seen during the moments of initial impact. The left wing is digging into the lakebed while the aircraft continues sliding towards wing openers. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive, Anti-misting Kerosene (AMK), designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and fueling a full-size aircraft). The 15 flights had 15 takeoffs, 14 landings and a larger number of approaches to about 150 feet above the prepared crash site under remote control. These flight were used to introduce AMK one step at a time into some of the fuel tanks and engines while monitoring the performance of the engines. On the final flight (No. 15) with no crew, all fuel tanks were filled with a total of 76,000 pounds of AMK and the remotely-piloted aircraft landed on Rogers Dry Lakebed in an area prepared with posts to test the effectiveness of the AMK in a controlled impact. The CID, which some wags called the Crash in the Desert, was spectacular with a large fireball enveloping and burning the B-720 aircraft. From the standpoint of AMK the test was a major set-back, but for NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

1984-01-01

380

Hypersonic reconnaissance aircraft  

NASA Technical Reports Server (NTRS)

A conceptual design of a hypersonic reconnaissance aircraft for the U.S. Navy is discussed. After eighteen weeks of work, a waverider design powered by two augmented turbofans was chosen. The aircraft was designed to be based on an aircraft carrier and to cruise 6,000 nautical miles at Mach 4;80,000 feet and above. As a result the size of the aircraft was only allowed to have a length of eighty feet, fifty-two feet in wingspan, and roughly 2,300 square feet in planform area. Since this is a mainly cruise aircraft, sixty percent of its 100,000 pound take-off weight is JP fuel. At cruise, the highest temperature that it will encounter is roughly 1,100 F, which can be handled through the use of a passive cooling system.

Bulk, Tim; Chiarini, David; Hill, Kevin; Kunszt, Bob; Odgen, Chris; Truong, Bon

1992-01-01

381

Why aircraft disinsection?  

PubMed Central

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.

Gratz, N. G.; Steffen, R.; Cocksedge, W.

2000-01-01

382

Design and flight test of the Propulsion Controlled Aircraft (PCA) flight control system on the NASA F-15 test aircraft  

NASA Technical Reports Server (NTRS)

This report describes the design, development and flight testing of the Propulsion Controlled Aircraft (PCA) flight control system performed at McDonnell Douglas Aerospace (MDA), St. Louis, Missouri and at the NASA Dryden Flight Research Facility, Edwards Air Force Base, California. This research and development program was conducted by MDA and directed by NASA through the Dryden Flight Research Facility for the period beginning January 1991 and ending December 1993. A propulsion steering backup to the aircraft conventional flight control system has been developed and flight demonstrated on a NASA F-15 test aircraft. The Propulsion Controlled Aircraft (PCA) flight system utilizes collective and differential thrust changes to steer an aircraft that experiences partial or complete failure of the hydraulically actuated control surfaces. The PCA flight control research has shown that propulsion steering is a viable backup flight control mode and can assist the pilot in safe landing recovery of a fighter aircraft that has damage to or loss of the flight control surfaces. NASA, USAF and Navy evaluation test pilots stated that the F-15 PCA design provided the control necessary to land the aircraft. Moreover, the feasibility study showed that PCA technology can be directly applied to transport aircraft and provide a major improvement in the survivability of passengers and crew of controls damaged aircraft.

Wells, Edward A.; Urnes, James M., Sr.

1994-01-01

383

Aircraft Maintenance Performance: The Effects of the Functional Decentralization of On-Equipment Maintenance.  

National Technical Information Service (NTIS)

The Air Force has implemented various aircraft maintenance organizational structures. The implementation of the Objective Wing in the early 1990s was the latest occurrence of reorganization. This research looks at the effect of the type of aircraft mainte...

M. A. Commenator

2001-01-01

384

Jet aircraft emissions during cruise: Present and future  

NASA Technical Reports Server (NTRS)

Forecasts of engine exhaust emissions that may be practicably achievable for future commercial aircraft operating at high altitude cruise conditions are compared to cruise emission for present day aircraft. The forecasts are based on: (1) knowledge of emission characteristics of combustors and augmentors; (2) combustion research in emission reduction technology, and (3) trends in projected engine designs for advanced subsonic or supersonic commercial aircraft. Recent progress that was made in the evolution of emissions reduction technology is discussed.

Grobman, J. S.

1975-01-01

385

Recent progress towards predicting aircraft ground handling performance  

NASA Technical Reports Server (NTRS)

Capability implemented in simulating aircraft ground handling performance is reviewed and areas for further expansion and improvement are identified. Problems associated with providing necessary simulator input data for adequate modeling of aircraft tire/runway friction behavior are discussed and efforts to improve tire/runway friction definition, and simulator fidelity are described. Aircraft braking performance data obtained on several wet runway surfaces are compared to ground vehicle friction measurements. Research to improve methods of predicting tire friction performance are discussed.

Yager, T. J.; White, E. J.

1981-01-01

386

The atmospheric effects of stratospheric aircraft  

NASA Technical Reports Server (NTRS)

This document presents a second report from the Atmospheric Effects of Stratospheric Aircraft (AESA) component of NASA's High-Speed Research Program (HSRP). This document presents a second report from the Atmospheric Effects of Stratospheric Aircraft (AESA) component of NASA's High Speed Research Program (HSRP). Market and technology considerations continue to provide an impetus for high-speed civil transport research. A recent United Nations Environment Program scientific assessment has shown that considerable uncertainty still exists about the possible impact of aircraft on the atmosphere. The AESA was designed to develop the body of scientific knowledge necessary for the evaluation of the impact of stratospheric aircraft on the atmosphere. The first Program report presented the basic objectives and plans for AESA. This second report presents the status of the ongoing research as reported by the principal investigators at the second annual AESA Program meeting in May 1992: Laboratory studies are probing the mechanism responsible for many of the heterogeneous reactions that occur on stratospheric particles. Understanding how the atmosphere redistributes aircraft exhaust is critical to our knowing where the perturbed air will go and for how long it will remain in the stratosphere. The assessment of fleet effects is dependent on the ability to develop scenarios which correctly simulate fleet operations.

Stolarski, Richard S. (editor); Wesoky, Howard L. (editor)

1993-01-01

387

Waterborne Polyurethane Binder Resins for Compliant Aircraft Coatings.  

National Technical Information Service (NTIS)

This Small Business Innovation Research (SBIR), Phase I research project investigated the feasibility of producing a one-component, water-borne, low volatile organic compounds (VOC) coating for the protection of naval aircraft and ground support equipment...

F. L. Koehan R. M. Stewart W. M. Gomes

1992-01-01

388

Aircraft Vortex Spacing System (AVOSS) Initial 1997 System Deployment at Dallas/Ft. Worth (DFW) Airport  

NASA Technical Reports Server (NTRS)

The potential hazard of aircraft encounters with the wake turbulence of preceding aircraft requires the use of minimum separations on landing that are significant constraint on airport arrival capacity during instrument flight rules (IFR) conditions. The National Aeronautics and Space Administration (NASA) Langley research Center has been researching the development of the Aircraft Vortex Spacing System (AVOSS) which would dynamically change aircraft arrival separations based on the forecasted weather conditions and vortex behavior.

Dasey, T. J.; Cole, R. E.; Heinrichs, R. M.; Matthews, M. P.; Perras, G. H.

1998-01-01

389

Predicting Visibility of Aircraft  

PubMed Central

Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO). In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration.

Watson, Andrew; Ramirez, Cesar V.; Salud, Ellen

2009-01-01

390

Nonclassical Flight Control for Unhealthy Aircraft  

NASA Technical Reports Server (NTRS)

This research set out to investigate flight control of aircraft which has sustained damage in regular flight control effectors, due to jammed control surfaces or complete loss of hydraulic power. It is recognized that in such an extremely difficult situation unconventional measures may need to be taken to regain control and stability of the aircraft. Propulsion controlled aircraft (PCA) concept, initiated at the NASA Dryden Flight Research Center. represents a ground-breaking effort in this direction. In this approach, the engine is used as the only flight control effector in the rare event of complete loss of normal flight control system. Studies and flight testing conducted at NASA Dryden have confirmed the feasibility of the PCA concept. During the course of this research (March 98, 1997 to November 30, 1997), a comparative study has been done using the full nonlinear model of an F-18 aircraft. Linear controllers and nonlinear controllers based on a nonlinear predictive control method have been designed for normal flight control system and propulsion controlled aircraft. For the healthy aircraft with normal flight control, the study shows that an appropriately designed linear controller can perform as well as a nonlinear controller. On the other hand. when the normal flight control is lost and the engine is the only available means of flight control, a nonlinear PCA controller can significantly increase the size of the recoverable region in which the stability of the unstable aircraft can be attained by using only thrust modulation. The findings and controller design methods have been summarized in an invited paper entitled.

Lu, Ping

1997-01-01

391

Lightning hazards to aircraft  

NASA Technical Reports Server (NTRS)

Lightning hazards and, more generally, aircraft static electricity are discussed by a representative for the Air Force Flight Dynamics Laboratory. An overview of these atmospheric electricity hazards to aircraft and their systems is presented with emphasis on electrical and electronic subsystems. The discussion includes reviewing some of the characteristics of lightning and static electrification, trends in weather and lightning-related mishaps, some specific threat mechanisms and susceptible aircraft subsystems and some of the present technology gaps. A roadmap (flow chart) is presented to show the direction needed to address these problems.

Corn, P. B.

1978-01-01

392

Tropospheric sampling with aircraft  

SciTech Connect

Aircraft constitute a unique environment which places stringent requirements on the instruments used to measure the concentrations of atmospheric trace gases and aerosols. Some of these requirements such as minimization of size, weight, and power consumption are general; others are specific to individual techniques. This review presents the basic principles and considerations governing the deployment of trace gas and aerosol instrumentation on an aircraft. An overview of common instruments illustrates these points and provides guidelines for designing and using instruments on aircraft-based measurement programs.

Daum, P.H.; Springston, S.R.

1991-03-01

393

Some fighter aircraft trends  

NASA Technical Reports Server (NTRS)

Some basic trends in fighters are traced from the post World II era. Beginning with the first operational jet fighter, the P-80, the characteristics of subsequent fighter aircraft are examined for performance, mission capability, effectiveness, and cost. Characteristics presented include: power loading, wing loading, maximum speed, rate of climb, turn rate, weight and weight distribution, cost and cost distribution. The characteristics of some USSR aircraft are included for comparison. The trends indicate some of the rationale for certain fighter designs and some likely characteristics to be sought in future fighter aircraft designs.

Spearman, L.

1985-01-01

394

Loftin Collection - Boeing Aircraft  

NASA Technical Reports Server (NTRS)

Either a F2B-1 or F3B-1, both aircraft were built by Boeing and both were powered by Pratt and Whitney Wasp engines. These fighters were intended for Navy shipboard use. Boeing F3B-1: While most Boeing F3B-1s served the U. S. Navy aircraft carriers the Lexington and the Saratoga, this example flew in NACA hands at the Langley Memorial Aeronautical Laboratory in the late 1920's. Also known as the Boeing Model 77, the aircraft was the next to last F3B-1 build in November 1928.

1933-01-01

395

Automatic aircraft recognition and identification  

Microsoft Academic Search

Aircraft recognition remains a challenging problem despite a great deal of effort to automate the recognition process. The majority of the aircraft recognition methods assume the successful isolation of the aircraft silhouette from the background, and only a few have actually addressed real world concerns, such as occlusion, clutter and shadows. This thesis presents an automatic aircraft recognition system, which

Jijoong Kim

2005-01-01

396

Takeoff predictions for powered-lift aircraft. Thesis  

NASA Technical Reports Server (NTRS)

Takeoff predictions for powered-lift short takeoff (STO) and conventional takeoff (CTO) aircraft have been added to NASA Ames Research Center's Aircraft Synthesis (ACSYNT) code. The new computer code predicts the aircraft engine and nozzle settings required to achieve the minimum takeoff roll. As a test case, the code predicted takeoff ground rolls and nozzle settings for the YAV-8B Harrier that compared well with measured values. Brief analysis of takeoff performance for an Ejector, Remote Augmented Lift, Hybrid-Tandem Fan, and Vectored Thrust STO aircraft using the new routine will be presented.

Wardwell, Douglas A.; Sandlin, Doral R.

1988-01-01

397

System design requirements for advanced rotary-wing agricultural aircraft  

NASA Technical Reports Server (NTRS)

Helicopter aerial dispersal systems were studied to ascertain constraints to the system, the effects of removal of limitations (technical and FAA regulations), and subsystem improvements. Productivity indices for the aircraft and swath effects were examined. Typical missions were formulated through conversations with operators, and differing gross weight aircraft were synthesized to perform these missions. Economic analysis of missions and aircraft indicated a general correlation of small aircraft (3000 lb gross weight) suitability for small fields (25 acres), and low dispersion rates (less than 32 lb/acre), with larger aircraft (12,000 lb gross weight) being more favorable for bigger fields (200 acres) and heavier dispersal rates (100 lb/acre). Operator problems, possible aircraft and system improvements, and selected removal of operating limitations were reviewed into recommendations for future NASA research items.

Lemont, H. E.

1979-01-01

398

Framework for the Conceptual Decomposition of Unmanned Aircraft Propulsion Systems  

Microsoft Academic Search

Propulsion for the aircraft segment in unmanned aircraft systems (UAS) is provided not only by widely used propulsion technologies such as reciprocating piston engines and jet and prop turbine engines, but also by electric motors running off some combination of batteries, solar cells, and fuel cells. These disparate propulsion technologies pose a challenge to researchers and regulators in comparing systems,

Christopher L. Griffis; Timothy A. Wilson; Jeffrey A. Schneider; Peter S. Pierpont

2008-01-01

399

An Analysis of Ball Lightning-Aircraft Incidents  

Microsoft Academic Search

Lightning is a rare but regular phenomenon for air traffic. Research and design have created aircraft that withstand average lightning strikes. Ball lightning (BL), a metastable, rare lightning type, is also observed from (and within) aircraft. Science and the media focused on individual BL incidents and did not analyze general patterns. Lacking established incident reporting channels, most BL observations are

R. K. Doe; A. G. Keul; V. Bychkov

2009-01-01

400

Aircraft Radiation Shield Experiments--Preflight Laboratory Testing  

Microsoft Academic Search

In the past, measurements onboard a research Boeing 57F (RB57-F) aircraft have demonstrated that the neutron environment within the aircraft structure is greater than that in the local external environment. Recent studies onboard Boeing 737 commercial flights have demonstrated cabin variations in radiation exposure up to 30 percent. These prior results were the basis of the present study to quantify

Robert C. Singleterry Jr.; Judy L. Shinn; John W. Wilson; Donald L. Maiden; Sheila A. Thibeault; Francis F. Badavi; Thomas Conroy; Leslie Braby

1999-01-01

401

Aircraft observations of the solar ultraviolet irradiance throughout the troposphere  

Microsoft Academic Search

Observations of the biological effective solar ultraviolet irradiance, made by instrumentation flown on a Falcon aircraft over the entire Greek area, from the sea up to the tropopause level, obtained in the frame of the Radiation Field in the Troposphere-Scientific Training and Access to Aircraft for Atmospheric Research Throughout Europe project, are presented to discuss among others its altitude dependence.

C. Varotsos; D. Alexandris; G. Chronopoulos; C. Tzanis

2001-01-01

402

Characterizations of Aircraft Icing Environments that Include Supercooled Large Drops  

Microsoft Academic Search

Measurements of aircraft icing environments that include supercooled large drops (SLD) greater than 50 mm in diameter have been made during 38 research flights. These flights were conducted during the First and Third Canadian Freezing Drizzle Experiments. A primary objective of each project was the collection of in situ microphysics data in order to characterize aircraft icing environments associated with

Stewart G. Cober; George A. Isaac; J. Walter Strapp

2001-01-01

403

Biodegradation of Aircraft Deicing Fluid Components in Soil.  

National Technical Information Service (NTIS)

Aircraft de-icing fluids (ADFs) are used worldwide to ensure safe aircraft operations. This research effort was conducted to analyze the biodegradation effects of two chemical components of ADFs, propylene glycol (PG) and tolyltriazole (TTA), in a high-cl...

B. W. Burke

1999-01-01

404

Aerogeophysical laboratory based on the Ilyushin-18 aircraft  

NASA Astrophysics Data System (ADS)

I talk about a flying laboratory based on the IL18 aircraft. It has been carrying out research since 1985. I talk about two modifications to this laboratory: First, the aircraft, which belongs to Civil Aviation Ministry, was to be modified. Second, more advanced modifications were carried out upon the IL18 which belongs to the Leninetz Concern.

Palamarchuk, Vasily K.; Kalinin, V. A.; Plotnikov, A. I.

1993-11-01

405

Development of Textile Reinforced Composites for Aircraft Structures  

Microsoft Academic Search

NASA has been a leader in development of composite materials for aircraft applications during the past 25 years. In the early 1980's NASA and others conducted research to improve damage tolerance of composite structures through the use of toughened resins but these resins were not cost- effective. The aircraft industry wanted affordable, robust structures that could withstand the rigors of

H. Benson Dexter

1998-01-01

406

Advanced hypersonic aircraft design  

NASA Technical Reports Server (NTRS)

The objective of this design project is to develop the hypersonic reconnaissance aircraft to replace the SR-71 and to complement existing intelligence gathering devices. The initial design considerations were to create a manned vehicle which could complete its mission with at least two airborne refuelings. The aircraft must travel between Mach 4 and Mach 7 at an altitude of 80,000 feet for a maximum range of 12,000 nautical miles. The vehicle should have an air breathing propulsion system at cruise. With a crew of two, the aircraft should be able to take off and land on a 10,000 foot runway, and the yearly operational costs were not to exceed $300 million. Finally, the aircraft should exhibit stealth characteristics, including a minimized radar cross-section (RCS) and a reduced sonic boom. The technology used in this vehicle should allow for production between the years 1993 and 1995.

Utzinger, Rob; Blank, Hans-Joachim; Cox, Craig; Harvey, Greg; Mckee, Mike; Molnar, Dave; Nagy, Greg; Petersen, Steve

1992-01-01

407

Optimum Aircraft Rescue Tool.  

National Technical Information Service (NTIS)

This report details the design, development, testing, and evaluation pertaining to two versions of an Optimum Aircraft Rescue Tool. The rescue tool is a lightweight device required to replace several manually operated tools used by rescue personnel when f...

E. W. LeMaster P. R. Hughes J. R. Jenkins

1983-01-01

408

Aircraft Centrifugal Pump Units.  

National Technical Information Service (NTIS)

A general description of the experience of Soviet and foreign industry with respect to calculation, designing, experimental studies, and operation of aircraft centrifugal pump units is given. The contemporary level of designs and prospects of their develo...

L. S. Arinushkin R. B. Abramovich E. A. Glozman A. Y. Polinovskii L. B. Leshchiner

1969-01-01

409

Aircraft Materials Test Bank  

NSDL National Science Digital Library

This Microsoft Word document from the Aerospace Manufacturing Education Project provides a bank of test questions on materials used in the aircraft industry. 35 test questions and their correct answers are included in this test bank.

2012-11-13

410

Aircraft electromagnetic compatibility  

NASA Technical Reports Server (NTRS)

Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.

Clarke, Clifton A.; Larsen, William E.

1987-01-01

411

Aircraft Engine Emissions. [conference  

NASA Technical Reports Server (NTRS)

A conference on a aircraft engine emissions was held to present the results of recent and current work. Such diverse areas as components, controls, energy efficient engine designs, and noise and pollution reduction are discussed.

1977-01-01

412

Depreciation of aircraft  

NASA Technical Reports Server (NTRS)

There is a widespread, and quite erroneous, impression to the effect that aircraft are essentially fragile and deteriorate with great rapidity when in service, so that the depreciation charges to be allowed on commercial or private operation are necessarily high.

Warner, Edward P

1922-01-01

413

Laminar Flow Aircraft Certification  

NASA Technical Reports Server (NTRS)

Various topics telative to laminar flow aircraft certification are discussed. Boundary layer stability, flaps for laminar flow airfoils, computational wing design studies, manufacturing requirements, windtunnel tests, and flow visualization are among the topics covered.

Williams, Louis J. (compiler)

1986-01-01

414

Alternative jet aircraft fuels  

NASA Technical Reports Server (NTRS)

Potential changes in jet aircraft fuel specifications due to shifts in supply and quality of refinery feedstocks are discussed with emphasis on the effects these changes would have on the performance and durability of aircraft engines and fuel systems. Combustion characteristics, fuel thermal stability, and fuel pumpability at low temperature are among the factors considered. Combustor and fuel system technology needs for broad specification fuels are reviewed including prevention of fuel system fouling and fuel system technology for fuels with higher freezing points.

Grobman, J.

1979-01-01

415

Eclipse program C-141A aircraft  

NASA Technical Reports Server (NTRS)

This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. The project used a QF-106 interceptor aircraft to simulate a future orbiter, which would be towed to a high altitude and released to fire its own engines and carry a payload into space. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

1997-01-01

416

Assessment of Alternative Aircraft Fuels  

NASA Technical Reports Server (NTRS)

The purpose of this symposium is to provide representatives from industry, government, and academia concerned with the availability and quality of future aviation turbine fuels with recent technical results and a status review of DOD and NASA sponsored fuels research projects. The symposium has included presentations on the potential crude sources, refining methods, and characteristics of future fuels; the effects of changing fuel characteristics on the performance and durability of jet aircraft components and systems; and the prospects for evolving suitable technology to produce and use future fuels.

1984-01-01

417

Cyberinfrastructure for Aircraft Mission Support  

NASA Technical Reports Server (NTRS)

Forth last several years NASA's Airborne Science Program has been developing and using infrastructure and applications that enable researchers to interact with each other and with airborne instruments via network communications. Use of these tools has increased near realtime situational awareness during field operations, resulting it productivity improvements, improved decision making, and the collection of better data. Advances in pre-mission planning and post-mission access have also emerged. Integrating these capabilities with other tools to evolve coherent service-oriented enterprise architecture for aircraft flight and test operations is the subject of ongoing efforts.

Freudinger, Lawrence C.

2010-01-01

418

Operational Concepts for Uninhabited Tactical Aircraft  

NASA Technical Reports Server (NTRS)

This paper describes experiences with five remotely piloted flight research vehicle projects in the developmental flight test phase. These projects include the Pathfinder, Perseus B, Altus, and X-36 aircraft and the Highly Maneuverable Aircraft Technology (HiMAT). Each of these flight projects was flown at the NASA Dryden Flight Research Center. With the exception of the HIMAT, these projects are a part of the Flight Research Base Research and Technology (R&T) Program of the NASA Aeronautics and Space Transportation Technology Enterprise. Particularly with respect to operational interfaces between the ground-based pilot or operator, this paper draws from those experiences, then provides some rationale for extending the lessons learned during developmental flight research to the possible situations involved in the developmental flights proceeding deployed uninhabited tactical aircraft (UTA) operations. Two types of UTA control approaches are considered: autonomous and remotely piloted. In each of these cases, some level of human operator or pilot control blending is recommended. Additionally, "best practices" acquired over years of piloted aircraft experience are drawn from and presented as they apply to operational UTA.

Deets, Dwain A.; Purifoy, Dana

1998-01-01

419

Case Study: Test Results of a Tool and Method for In-Flight, Adaptive Control System Verification on a NASA F-15 Flight Research Aircraft  

NASA Technical Reports Server (NTRS)

Adaptive control technologies that incorporate learning algorithms have been proposed to enable autonomous flight control and to maintain vehicle performance in the face of unknown, changing, or poorly defined operating environments [1-2]. At the present time, however, it is unknown how adaptive algorithms can be routinely verified, validated, and certified for use in safety-critical applications. Rigorous methods for adaptive software verification end validation must be developed to ensure that. the control software functions as required and is highly safe and reliable. A large gap appears to exist between the point at which control system designers feel the verification process is complete, and when FAA certification officials agree it is complete. Certification of adaptive flight control software verification is complicated by the use of learning algorithms (e.g., neural networks) and degrees of system non-determinism. Of course, analytical efforts must be made in the verification process to place guarantees on learning algorithm stability, rate of convergence, and convergence accuracy. However, to satisfy FAA certification requirements, it must be demonstrated that the adaptive flight control system is also able to fail and still allow the aircraft to be flown safely or to land, while at the same time providing a means of crew notification of the (impending) failure. It was for this purpose that the NASA Ames Confidence Tool was developed [3]. This paper presents the Confidence Tool as a means of providing in-flight software assurance monitoring of an adaptive flight control system. The paper will present the data obtained from flight testing the tool on a specially modified F-15 aircraft designed to simulate loss of flight control faces.

Jacklin, Stephen A.; Schumann, Johann; Guenther, Kurt; Bosworth, John

2006-01-01

420

Cockpit automation concept development for the NUH-60 (STAR) aircraft  

Microsoft Academic Search

Results of a study performed to derive an automation and avionics integration design concept for the NUH-60 systems testbed for avionics research (STAR) aircraft are presented. The STAR aircraft is being developed by the US Army avionics research and development activity to provide a flight demonstrator and research vehicle for state-of-the-art cockpit technology. A goal was to determine cockpit design

D. D. Riley; P. G. Stringer

1988-01-01

421

Aircraft power systems: technology, state of the art, and future trends  

Microsoft Academic Search

The fundamental issues faced in the aircraft electrical power systems are addressed. A brief description of the conventional and advanced aircraft power system architectures, their disadvantages, opportunities for improvement, future electric loads, role of power electronics, and present trends in aircraft power system research is given, followed by a brief outline of projected future advancements

K. Emadi; M. Ehsani

2000-01-01

422

Ultrasonic Measurement of Aircraft Strut Hydraulic Fluid Level  

NASA Technical Reports Server (NTRS)

An ultrasonic method is presented for non-intrusively measuring hydraulic fluid level in aircraft struts in the field quickly and easily without modifying the strut or aircraft. The technique interrogates the strut with ultrasonic waves generated and received by a removable ultrasonic transducer hand-held on the outside of the strut in a fashion that is in the presence or absence of hydraulic fluid inside the strut. This technique was successfully demonstrated on an A-6 aircraft strut on the carriage at the Aircraft Landing Dynamics Research Facility at NASA Langley Research Center. Conventional practice upon detection of strut problem symptoms is to remove aircraft from service for extensive maintenance to determine fluid level. No practical technique like the method presented herein for locating strut hydraulic fluid level is currently known to be used.

Allison, Sidney G.

2002-01-01