Design of a digital ride quality augmentation system for commuter aircraft

NASA Technical Reports Server (NTRS)

Hammond, T. A.; Amin, S. P.; Paduano, J. D.; Downing, D. R.

1984-01-01

Commuter aircraft typically have low wing loadings, and fly at low altitudes, and so they are susceptible to undesirable accelerations caused by random atmospheric turbulence. Larger commercial aircraft typically have higher wing loadings and fly at altitudes where the turbulence level is lower, and so they provide smoother rides. This project was initiated based on the goal of making the ride of the commuter aircraft as smooth as the ride experienced on the major commercial airliners. The objectives of this project were to design a digital, longitudinal mode ride quality augmentation system (RQAS) for a commuter aircraft, and to investigate the effect of selected parameters on those designs.

Altus II aircraft flying over southern California desert

NASA Technical Reports Server (NTRS)

1998-01-01

The snow-capped peak of Mt. San Antonio in the San Gabriel range is visible as the the remotely piloted Altus II flies over Southern California's high desert. The Altus II was flown as a performance and propulsion testbed for future high-altitude science platform aircraft under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program at the Dryden Flight Research Center, Edwards, Calif. The rear-engined Altus II and its sister ship, the Altus I, were built by General Atomics/Aeronautical Systems, Inc., of San Diego, Calif. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I, built for the Naval Postgraduate School, reached over 43,500 feet with a single-stage turbocharger feeding its four-cylinder Rotax engine in 1997, while the Altus II, incorporating a two-stage turbocharger built by Thermo-Mechanical Systems, reached and sustained an altitudeof 55,000 feet for four hours in 1999. A pilot in a control station on the ground flies 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.

Altus II aircraft flying over southern California desert

NASA Technical Reports Server (NTRS)

1998-01-01

The San Gabriel range is visible as the the remotely piloted Altus II flies over Southern California's high desert. The Altus II was flown as a performance and propulsion testbed for future high-altitude science platform aircraft under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program at the Dryden Flight Research Center, Edwards, Calif. The rear-engined Altus II and its sister ship, the Altus I, were built by General Atomics/Aeronautical Systems, Inc., of San Diego, Calif. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I, built for the Naval Postgraduate School, reached over 43,500 feet with a single-stage turbocharger feeding its four-cylinder Rotax engine in 1997, while the Altus II, incorporating a two-stage turbocharger built by Thermo-Mechanical Systems, reached and sustained an altitudeof 55,000 feet for four hours in 1999. A pilot in a control station on the ground flies 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.

Response Sensitivity of Typical Aircraft Jet Engine Fan Blade-Like Structures to Bird Impacts.

DTIC Science & Technology

1982-05-01

AIRCRAFT ENGINE BU--ETC F/G 21/5 RESPONSE SENSITIVITY OF TYPICAL AIRCRAFT JET ENGINE FAN BLADE -L...SENSITIVITY OF TYPICAL AIRCRAFT JET ENGINE FAN BLADE -LIKE STRUCTURES TO BIRD IMPACTS David P. Bauer Robert S. Bertke University of Dayton Research...COVERED RESPONSE SENSITIVITY OF TYPICAL AIRCRAFT FINAL REPORT JET ENGINE FAN BLADE -LIKE STRUCTURES Oct. 1977 to Jan. 1979 TO BIRD IMPACTS s.

Conceptual design for a laminar-flying-wing aircraft

NASA Astrophysics Data System (ADS)

Saeed, T. I.

The laminar-flying-wing aircraft appears to be an attractive long-term prospect for reducing the environmental impact of commercial aviation. In assessing its potential, a relatively straightforward initial step is the conceptual design of a version with restricted sweep angle. Such a design is the topic of this thesis. Subject to constraints, this research aims to; provide insight into the parameters affecting practical laminar-flow-control suction power requirements; identify a viable basic design specification; and, on the basis of this, an assessment of the fuel efficiency through a detailed conceptual design study. It is shown that there is a minimum power requirement independent of the suction system design, associated with the stagnation pressure loss in the boundary layer. This requirement increases with aerofoil section thickness, but depends only weakly on Mach number and (for a thick, lightly-loaded laminar flying wing) lift coefficient. Deviation from the optimal suction distribution, due to a practical chamber-based architecture, is found to have very little effect on the overall suction coefficient. In the spanwise direction, through suitable choice of chamber depth, the pressure drop due to frictional and inertial effects may be rendered negligible. Finally, it is found that the pressure drop from the aerofoil surface to the pump collector ducts determines the power penalty. To identify the viable basic design specification, a high-level exploration of the laminar flying wing design space is performed. The characteristics of the design are assessed as a function of three parameters: thickness-to-chord ratio, wingspan, and unit Reynolds number. A feasible specification, with 20% thickness-to-chord, 80 m span and a unit Reynolds number of 8 x 106 m-1, is identified; it corresponds to a 187 tonne aircraft which cruises at Mach 0.67 and altitude 22,500 ft, with lift coefficient 0.14. On the basis of this specification, a detailed conceptual design is

Lateral-Directional Eigenvector Flying Qualities Guidelines for High Performance Aircraft

NASA Technical Reports Server (NTRS)

Davidson, John B.; Andrisani, Dominick, II

1996-01-01

This report presents the development of lateral-directional flying qualities guidelines with application to eigenspace (eigenstructure) assignment methods. These guidelines will assist designers in choosing eigenvectors to achieve desired closed-loop flying qualities or performing trade-offs between flying qualities and other important design requirements, such as achieving realizable gain magnitudes or desired system robustness. This has been accomplished by developing relationships between the system's eigenvectors and the roll rate and sideslip transfer functions. Using these relationships, along with constraints imposed by system dynamics, key eigenvector elements are identified and guidelines for choosing values of these elements to yield desirable flying qualities have been developed. Two guidelines are developed - one for low roll-to-sideslip ratio and one for moderate-to-high roll-to-sideslip ratio. These flying qualities guidelines are based upon the Military Standard lateral-directional coupling criteria for high performance aircraft - the roll rate oscillation criteria and the sideslip excursion criteria. Example guidelines are generated for a moderate-to-large, an intermediate, and low value of roll-to-sideslip ratio.

The solar-powered Helios Prototype flying wing frames two modified F-15 research aircraft in a hanga

NASA Technical Reports Server (NTRS)

2002-01-01

The solar-powered Helios Prototype flying wing frames two modified F-15 research aircraft in a hangar at NASA's Dryden flight Research Center, Edwards, California. The elongated 247-foot span lightweight aircraft, resting on its ground maneuvering dolly, stretched almost the full length of the 300-foot long hangar while on display during a visit of NASA Administrator Sean O'Keefe and other NASA officials on Jan. 31, 2002. The unique solar-electric flying wing reached an altitude of 96,863 feet during an almost 17-hour flight near Hawaii on Aug. 13, 2001, a world record for sustained horizontal flight by a non-rocket powered aircraft. Developed by AeroVironment, Inc., under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, the Helios Prototype is the forerunner of a planned fleet of slow-flying, long duration, high-altitude uninhabited aerial vehicles (UAV) which can serve as 'atmospheric satellites,' performing Earth science missions or functioning as telecommunications relay platforms in the stratosphere.

How to fly an aircraft with control theory and splines

NASA Technical Reports Server (NTRS)

Karlsson, Anders

1994-01-01

When trying to fly an aircraft as smoothly as possible it is a good idea to use the derivatives of the pilot command instead of using the actual control. This idea was implemented with splines and control theory, in a system that tries to model an aircraft. Computer calculations in Matlab show that it is impossible to receive enough smooth control signals by this way. This is due to the fact that the splines not only try to approximate the test function, but also its derivatives. A perfect traction is received but we have to pay in very peaky control signals and accelerations.

These two NASA F/A-18 aircraft are flying a test point for the Autonomous Formation Flight project o

NASA Technical Reports Server (NTRS)

2001-01-01

Two NASA F/A-18 aircraft are flying a test point for the Autonomous Formation Flight project over California's Mojave Desert. This second flight phase is mapping the wingtip vortex of the lead aircraft, the Systems Research Aircraft (tail number 847), on the trailing F/A-18 tail number 847. Wingtip vortex is a spiraling wind flowing from the wing during flight. The project is studying the drag and fuel reduction of precision formation flying.

A Simulation Study on Take-Off and Landing Dynamics of the Aircraft of a Fly-By-Wire Control System

DTIC Science & Technology

1993-01-07

L:V,"DIN G DYN;AMICS OF THE AIRCRAFT OF A FLY-BY-WIRE CONTROL SYSTEM by Y achang Feng, Gang Chert, Peiqiong Li 93-00985 Distribution unlimit ed. FASTC...FLY-BY-WIRE CONTROL SYSTEM By: Yachang Feng, Gang Chen, Peiqiong- Li English pages: 17 Source: Hangkon, Xuebao, Vol. 12, No. 6, June, 1991; pp. 252-258...Landing Dynamics of the Aircraft of a Fly-By-Wire Control System Beijing University of Aeronautics and Astronautics Yachang FENG, Gang CHEN and Peiqiong Li

Topological structures of vortex flow on a flying wing aircraft, controlled by a nanosecond pulse discharge plasma actuator

NASA Astrophysics Data System (ADS)

Du, Hai; Shi, Zhiwei; Cheng, Keming; Wei, Dechen; Li, Zheng; Zhou, Danjie; He, Haibo; Yao, Junkai; He, Chengjun

2016-06-01

Vortex control is a thriving research area, particularly in relation to flying wing or delta wing aircraft. This paper presents the topological structures of vortex flow on a flying wing aircraft controlled by a nanosecond plasma dielectric barrier discharge actuator. Experiments, including oil flow visualization and two-dimensional particle image velocimetry (PIV), were conducted in a wind tunnel with a Reynolds number of 0.5 × 106. Both oil and PIV results show that the vortex can be controlled. Oil topological structures on the aircraft surface coincide with spatial PIV flow structures. Both indicate vortex convergence and enhancement when the plasma discharge is switched on, leading to a reduced region of separated flow.

A design study for a simple-to-fly, constant attitude light aircraft

NASA Technical Reports Server (NTRS)

Smetana, F. O.; Humphreys, D. E.; Montoya, R. J.; Rickard, W. W.; Wilkinson, I. E.

1973-01-01

The activities during a four-year study by doctoral students to evolve in detail a design for a simple-to-fly, constant attitude light airplane are described. The study indicated that such aircraft could materially reduce the hazards to light airplane occupants which arise from the high pilot work load and poor visibility that occur during landing. Preliminary cost studies indicate that in volume production this system would increase the cost of the aircraft in roughly the same fashion that automatic transmission, power steering, power brakes, and cruise control increase the cost of a compact car.

Ocean Color Inferred from Radiometers on Low-Flying Aircraft

PubMed Central

Churnside, James H.; Wilson, James J.

2008-01-01

The color of sunlight reflected from the ocean to orbiting visible radiometers has provided a great deal of information about the global ocean, after suitable corrections are made for atmospheric effects. Similar ocean-color measurements can be made from a low-flying aircraft to get higher spatial resolution and to obtain measurements under clouds. A different set of corrections is required in this case, and we describe algorithms to correct for clouds and sea-surface effects. An example is presented and errors in the corrections discussed. PMID:27879739

Using Sorties vs. Flying Hours to Predict Aircraft Spares Demand

DTIC Science & Technology

1997-04-01

the war plans, the demand for air- craft spares was substantially less than expected. This expected demand was based on the standard U.S. Air Force...by some combination of them. The Air Force’s new war plans for tactical aircraft in the 1993 USAF War and Mobilization Plan, Volume 5 (WMP-5) have...to continue to use flying hours as the basis for predicting wartime demand from peacetime experience, the cost of the war - time spares requirement

Fly in Atmosphere by Drag Force - Easy Thrust Generation Aircraft Engine Based Physics

NASA Astrophysics Data System (ADS)

Pierre Celestin, Mwizerwa

2013-11-01

This paper aims to present to the science community another way to fly in atmosphere, a way which is much more cheaper, efficient, safe and easy. Over the years scientists have been trying to find a way to built the vertically taking off vehicles but there have been no satisfactory success(what have been found was very expensive), Even aircrafts we know now need very sophisticated and expensive engines and not efficient enough. This way of flying may help our governments to spend less money on technologies and will help people to travel at very low prices so that, it may be a solution to the crisis which the world faces nowadays. In other words, it is my proposal to the next generation technologies we was looking for for years because everything can fly from the car to the trucks, the spaceships and even the hotels maybe constructed and fly as we construct the ships which sail in the oceans. My way of flying will have many applications in all the aspect of travel as it is going to be explained.

The Cognitive Challenges of Flying a Remotely Piloted Aircraft

NASA Technical Reports Server (NTRS)

Hobbs, Alan; Cardoza, Colleen; Null, Cynthia

2016-01-01

A large variety of Remotely Piloted Aircraft (RPA) designs are currently in production or in development. These aircraft range from small electric quadcopters that are flown close to the ground within visual range of the operator, to larger systems capable of extended flight in airspace shared with conventional aircraft. Before RPA can operate routinely and safely in civilian airspace, we need to understand the unique human factors associated with these aircraft. The task of flying an RPA in civilian airspace involves challenges common to the operation of other highly-automated systems, but also introduces new considerations for pilot perception, decision-making, and action execution. RPA pilots participated in focus groups where they were asked to recall critical incidents that either presented a threat to safety, or highlighted a case where the pilot contributed to system resilience or mission success. Ninety incidents were gathered from focus-groups. Human factor issues included the impact of reduced sensory cues, traffic separation in the absence of an out-the-window view, control latencies, vigilance during monotonous and ultra-long endurance flights, control station design considerations, transfer of control between control stations, the management of lost link procedures, and decision-making during emergencies. Some of these concerns have received significant attention in the literature, or are analogous to human factors of manned aircraft. The presentation will focus on issues that are poorly understood, and have not yet been the subject of extensive human factors study. Although many of the reported incidents were related to pilot error, the participants also provided examples of the positive contribution that humans make to the operation of highly-automated systems.

Flying Unmanned Aircraft: A Pilot's Perspective

NASA Technical Reports Server (NTRS)

Pestana, Mark E.

2011-01-01

The National Aeronautics and Space Administration (NASA) is pioneering various Unmanned Aircraft System (UAS) technologies and procedures which may enable routine access to the National Airspace System (NAS), with an aim for Next Gen NAS. These tools will aid in the development of technologies and integrated capabilities that will enable high value missions for science, security, and defense, and open the door to low-cost, extreme-duration, stratospheric flight. A century of aviation evolution has resulted in accepted standards and best practices in the design of human-machine interfaces, the displays and controls of which serve to optimize safe and efficient flight operations and situational awareness. The current proliferation of non-standard, aircraft-specific flight crew interfaces in UAS, coupled with the inherent limitations of operating UAS without in-situ sensory input and feedback (aural, visual, and vestibular cues), has increased the risk of mishaps associated with the design of the "cockpit." The examples of current non- or sub- standard design features range from "annoying" and "inefficient", to those that are difficult to manipulate or interpret in a timely manner, as well as to those that are "burdensome" and "unsafe." A concerted effort is required to establish best practices and standards for the human-machine interfaces, for the pilot as well as the air traffic controller. In addition, roles, responsibilities, knowledge, and skill sets are subject to redefining the terms, "pilot" and "air traffic controller", with respect to operating UAS, especially in the Next-Gen NAS. The knowledge, skill sets, training, and qualification standards for UAS operations must be established, and reflect the aircraft-specific human-machine interfaces and control methods. NASA s recent experiences flying its MQ-9 Ikhana in the NAS for extended duration, has enabled both NASA and the FAA to realize the full potential for UAS, as well as understand the implications of

Piloting Vertical Flight Aircraft: A Conference on Flying Qualities and Human Factors

NASA Technical Reports Server (NTRS)

Blanken, Christopher L. (Editor); Whalley, Matthew S. (Editor)

1993-01-01

This document contains papers from a specialists' meeting entitled 'Piloting Vertical Flight Aircraft: A Conference on Flying Qualities and Human Factors.' Vertical flight aircraft, including helicopters and a variety of Vertical Takeoff and Landing (VTOL) concepts, place unique requirements on human perception, control, and performance for the conduct of their design missions. The intent of this conference was to examine, for these vehicles, advances in: (1) design of flight control systems for ADS-33C standards; (2) assessment of human factors influences of cockpit displays and operational procedures; (3) development of VTOL design and operational criteria; and (4) development of theoretical methods or models for predicting pilot/vehicle performance and mission suitability. A secondary goal of the conference was to provide an initial venue for enhanced interaction between human factors and handling qualities specialists.

Technical problems encountered with the LALA-1 flying laboratory

NASA Technical Reports Server (NTRS)

Swidzinski, J.

1978-01-01

A description is given of structural design changes necessitated by the conversion of the An-2R agricultural support aircraft into a flying test bed to be used in feasibility studies evaluating jet engines in agricultural support aircraft. The entire rear of the fuselage was radically modified to permit mounting of the Al-25 jet engine directly behind the trailing edge of the upper wing. The standard piston engine was retained to permit comparison between the two types of power plants in typical agricultural support operations.

Thermodynamic correction of particle concentrations measured by underwing probes on fast flying aircraft

NASA Astrophysics Data System (ADS)

Weigel, R.; Spichtinger, P.; Mahnke, C.; Klingebiel, M.; Afchine, A.; Petzold, A.; Krämer, M.; Costa, A.; Molleker, S.; Jurkat, T.; Minikin, A.; Borrmann, S.

2015-12-01

Particle concentration measurements with underwing probes on aircraft are impacted by air compression upstream of the instrument body as a function of flight velocity. In particular for fast-flying aircraft the necessity arises to account for compression of the air sample volume. Hence, a correction procedure is needed to invert measured particle number concentrations to ambient conditions that is commonly applicable for different instruments to gain comparable results. In the compression region where the detection of particles occurs (i.e. under factual measurement conditions), pressure and temperature of the air sample are increased compared to ambient (undisturbed) conditions in certain distance away from the aircraft. Conventional procedures for scaling the measured number densities to ambient conditions presume that the particle penetration speed through the instruments' detection area equals the aircraft speed (True Air Speed, TAS). However, particle imaging instruments equipped with pitot-tubes measuring the Probe Air Speed (PAS) of each underwing probe reveal PAS values systematically below those of the TAS. We conclude that the deviation between PAS and TAS is mainly caused by the compression of the probed air sample. From measurements during two missions in 2014 with the German Gulfstream G-550 (HALO - High Altitude LOng range) research aircraft we develop a procedure to correct the measured particle concentration to ambient conditions using a thermodynamic approach. With the provided equation the corresponding concentration correction factor ξ is applicable to the high frequency measurements of each underwing probe which is equipped with its own air speed sensor (e.g. a pitot-tube). ξ-values of 1 to 0.85 are calculated for air speeds (i.e. TAS) between 60 and 260 m s-1. From HALO data it is found that ξ does not significantly vary between the different deployed instruments. Thus, for the current HALO underwing probe configuration a parameterisation of

Preliminary system design study for a digital fly-by-wire flight control system for an F-8C aircraft

NASA Technical Reports Server (NTRS)

Seacord, C. L.; Vaughn, D. K.

1976-01-01

The design of a fly-by-wire control system having a mission failure probability of less than one millionth failures per flight hour is examined. Emphasis was placed on developing actuator configurations that would improve the system performance, and consideration of the practical aspects of sensor/computer and computer/actuator interface implementation. Five basic configurations were defined as appropriate candidates for the F-8C research aircraft. Options on the basic configurations were included to cover variations in flight sensors, redundancy levels, data transmission techniques, processor input/output methods, and servo actuator arrangements. The study results can be applied to fly by wire systems for transport aircraft in general and the space shuttle.

Preliminary tests of vulnerability of typical aircraft electronics to lightning-induced voltages

NASA Technical Reports Server (NTRS)

Plumer, J. A.; Walko, L. C.

1974-01-01

Tests made on two pieces of typical aircraft electronics equipment to ascertain their vulnerability to simulated lightning-induced transient voltages representative of those which might occur in flight when the aircraft is struck by lightning were conducted. The test results demonstrated that such equipment can be interfered with or damaged by transient voltages as low as 21 volts peak. Greater voltages can cause failure of semiconductor components within the equipment. The results emphasize a need for establishment of coordinated system susceptibility and component vulnerability criteria to achieve lightning protection of aerospace electrical and electronic systems.

Investigation of controlled flight into terrain : aircraft accidents involving turbine-powered aircraft with six or more passenger seats flying under FAR part 91 flight rules and the potential for their prevention by ground proximity warning systems

DOT National Transportation Integrated Search

1996-03-01

This two-volume study documents an investigation of controlled flight into terrain (CFIT) aircraft accidents involving turbine-powered aircraft with six or more passenger seats flying under Federal Aviation Regulations (FAR) Part 91 flight rules, and...

32 CFR 855.13 - Civil fly-ins.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Civil fly-ins. 855.13 Section 855.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits § 855.13 Civil fly-ins. (a) Civil...

32 CFR 855.13 - Civil fly-ins.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Civil fly-ins. 855.13 Section 855.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits § 855.13 Civil fly-ins. (a) Civil...

NASA advanced design program. Design and analysis of a radio-controlled flying wing aircraft

NASA Technical Reports Server (NTRS)

1993-01-01

The main challenge of this project was to design an aircraft that will achieve stability while flying without a horizontal tail. The project focused on both the design, analysis and construction of a remotely piloted, elliptical shaped flying wing. The design team was composed of four sub-groups each of which dealt with the different aspects of the design, namely aerodynamics, stability and control, propulsion, and structures. Each member of the team initially researched the background information pertaining to specific facets of the project. Since previous work on this topic was limited, most of the focus of the project was directed towards developing an understanding of the natural instability of the aircraft. Once the design team entered the conceptual stage of the project, a series of compromises had to be made to satisfy the unique requirements of each sub-group. As a result of the numerous calculations and iterations necessary, computers were utilized extensively. In order to visualize the design and layout of the wing, engines and control surfaces, a solid modeling package was used to evaluate optimum design placements. When the design was finalized, construction began with the help of all the members of the project team. The nature of the carbon composite construction process demanded long hours of manual labor. The assembly of the engine systems also required precision hand work. The final product of this project is the Elang, a one-of-a-kind remotely piloted aircraft of composite construction powered by two ducted fan engines.

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

NASA Technical Reports Server (NTRS)

Navarro, Robert

2007-01-01

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.

Thermodynamic correction of particle concentrations measured by underwing probes on fast-flying aircraft

NASA Astrophysics Data System (ADS)

Weigel, Ralf; Spichtinger, Peter; Mahnke, Christoph; Klingebiel, Marcus; Afchine, Armin; Petzold, Andreas; Krämer, Martina; Costa, Anja; Molleker, Sergej; Reutter, Philipp; Szakáll, Miklós; Port, Max; Grulich, Lucas; Jurkat, Tina; Minikin, Andreas; Borrmann, Stephan

2016-10-01

Particle concentration measurements with underwing probes on aircraft are impacted by air compression upstream of the instrument body as a function of flight velocity. In particular, for fast-flying aircraft the necessity arises to account for compression of the air sample volume. Hence, a correction procedure is needed to invert measured particle number concentrations to ambient conditions that is commonly applicable to different instruments to gain comparable results. In the compression region where the detection of particles occurs (i.e. under factual measurement conditions), pressure and temperature of the air sample are increased compared to ambient (undisturbed) conditions in certain distance away from the aircraft. Conventional procedures for scaling the measured number densities to ambient conditions presume that the air volume probed per time interval is determined by the aircraft speed (true air speed, TAS). However, particle imaging instruments equipped with pitot tubes measuring the probe air speed (PAS) of each underwing probe reveal PAS values systematically below those of the TAS. We conclude that the deviation between PAS and TAS is mainly caused by the compression of the probed air sample. From measurements during two missions in 2014 with the German Gulfstream G-550 (HALO - High Altitude LOng range) research aircraft we develop a procedure to correct the measured particle concentration to ambient conditions using a thermodynamic approach. With the provided equation, the corresponding concentration correction factor ξ is applicable to the high-frequency measurements of the underwing probes, each of which is equipped with its own air speed sensor (e.g. a pitot tube). ξ values of 1 to 0.85 are calculated for air speeds (i.e. TAS) between 60 and 250 m s-1. For different instruments at individual wing position the calculated ξ values exhibit strong consistency, which allows for a parameterisation of ξ as a function of TAS for the current HALO

Analytical redundancy management mechanization and flight data analysis for the F-8 digital fly-by-wire aircraft flight control sensors

NASA Technical Reports Server (NTRS)

Deckert, J. C.

1983-01-01

The details are presented of an onboard digital computer algorithm designed to reliably detect and isolate the first failure in a duplex set of flight control sensors aboard the NASA F-8 digital fly-by-wire aircraft. The algorithm's successful flight test program is summarized, and specific examples are presented of algorithm behavior in response to software-induced signal faults, both with and without aircraft parameter modeling errors.

Aircraft as Research Tools

NASA Technical Reports Server (NTRS)

1999-01-01

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

Development and application of linear and nonlinear methods for interpretation of lightning strikes to in-flight aircraft

NASA Technical Reports Server (NTRS)

Rudolph, Terence; Perala, Rodney A.; Easterbrook, Calvin C.; Parker, Steven L.

1986-01-01

Since 1980, NASA has been collecting direct strike lightning data by flying an instrumented F-106B aircraft into thunderstorms. The continuing effort to interpret the measured data is reported here. Both linear and nonlinear finite difference modeling techniques are applied to the problem of lightning triggered by an aircraft in a thunderstorm. Five different aircraft are analyzed to determine the effect of aircraft size and shape on lightning triggering. The effect of lightning channel impedance on aircraft response is investigated. The particle environment in thunderstorms and electric field enhancements by typical ice particles is also investigated.

System for indicating fuel-efficient aircraft altitude

NASA Technical Reports Server (NTRS)

Gary, B. L. (Inventor)

1984-01-01

A method and apparatus are provided for indicating the altitude at which an aircraft should fly so the W/d ratio (weight of the aircraft divided by the density of air) more closely approaches the optimum W/d for the aircraft. A passive microwave radiometer on the aircraft is directed at different angles with respect to the horizon to determine the air temperature, and therefore the density of the air, at different altitudes. The weight of the aircraft is known. The altitude of the aircraft is changed to fly the aircraft at an altitude at which is W/d ratio more closely approaches the optimum W/d ratio for that aircraft.

41 CFR 301-70.909 - What disclosure information must we give to anyone who flies on our Government aircraft?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false What disclosure information must we give to anyone who flies on our Government aircraft? 301-70.909 Section 301-70.909 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES...

41 CFR 301-70.909 - What disclosure information must we give to anyone who flies on our Government aircraft?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 41 Public Contracts and Property Management 4 2014-07-01 2014-07-01 false What disclosure information must we give to anyone who flies on our Government aircraft? 301-70.909 Section 301-70.909 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES...

41 CFR 301-70.909 - What disclosure information must we give to anyone who flies on our Government aircraft?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 41 Public Contracts and Property Management 4 2013-07-01 2012-07-01 true What disclosure information must we give to anyone who flies on our Government aircraft? 301-70.909 Section 301-70.909 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES...

41 CFR 301-70.909 - What disclosure information must we give to anyone who flies on our Government aircraft?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false What disclosure information must we give to anyone who flies on our Government aircraft? 301-70.909 Section 301-70.909 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES...

A Flying Summer Camp

ERIC Educational Resources Information Center

Mercurio, Frank X.

1975-01-01

Describes a five-day summer camp which provided 12 children, ages 9-14, with a complete flying experience. The training consisted of ground school and one hour actual flying time, including the basics of aircraft control and a flight prepared and executed by the students. (MLH)

Aircraft of the future

NASA Technical Reports Server (NTRS)

Yeger, S.

1985-01-01

Some basic problems connected with attempts to increase the size and capacity of transport aircraft are discussed. According to the square-cubic law, the increase in structural weight is proportional to the third power of the increase in the linear dimensions of the aircraft when geomettric similarity is maintained, while the surface area of the aircraft increases according to the second power. A consequence is that the fraction of useful weight will decrease as aircraft increase in size. However, in flying-wing designs in which the whole load on the wing is proportional to the distribution of lifting forces, the total bending moment on the wing will be sharply reduced, enabling lighter construction. Flying wings may have an ultimate capacity of 3000 passengers.

Mapping automotive like controls to a general aviation aircraft

NASA Astrophysics Data System (ADS)

Carvalho, Christopher G.

The purpose of this thesis was to develop fly-by-wire control laws enabling a general aviation aircraft to be flown with automotive controls, i.e. a steering wheel and gas/brake pedals. There was a six speed shifter used to change the flight mode of the aircraft. This essentially allows the pilot to have control over different aspects of the flight profile such as climb/descend or cruise. A highway in the sky was used to aid in the navigation since it is not intuitive to people without flight experience how to navigate from the sky or when to climb and descend. Many believe that general aviation could become as widespread as the automobile. Every person could have a personal aircraft at their disposal and it would be as easy to operate as driving an automobile. The goal of this thesis is to fuse the ease of drivability of a car with flight of a small general aviation aircraft. A standard automotive control hardware setup coupled with variably autonomous control laws will allow new pilots to fly a plane as easily as driving a car. The idea is that new pilots will require very little training to become proficient with these controls. Pilots with little time to stay current can maintain their skills simply by driving a car which is typically a daily activity. A human factors study was conducted to determine the feasibility of the applied control techniques. Pilot performance metrics were developed to compare candidates with no aviation background and experienced pilots. After analyzing the relative performance between pilots and non-pilots, it has been determined that the control system is robust and easy to learn. Candidates with no aviation experience whatsoever can learn to fly an aircraft as safely and efficiently as someone with hundreds of hours of flight experience using these controls.

Flying wings / flying fuselages

NASA Technical Reports Server (NTRS)

Wood, Richard M.; Bauer, Steven X. S.

2001-01-01

The present paper has documented the historical relationships between various classes of all lifting vehicles, which includes the flying wing, all wing, tailless, lifting body, and lifting fuselage. The diversity in vehicle focus was to ensure that all vehicle types that map have contributed to or been influenced by the development of the classical flying wing concept was investigated. The paper has provided context and perspective for present and future aircraft design studies that may employ the all lifting vehicle concept. The paper also demonstrated the benefit of developing an understanding of the past in order to obtain the required knowledge to create future concepts with significantly improved aerodynamic performance.

Pathfinder-Plus aircraft in flight

NASA Technical Reports Server (NTRS)

1998-01-01

The Pathfinder-Plus solar-powered aircraft is shown taking off from a runway, then flying at low altitude over the ocean. The vehicle, which looks like a flying ruler, operates at low airspeed. Among the missions proposed for a solar-powered aircraft are communications relay, atmospheric studies, pipeline monitoring and gas leak detection, environmental monitoring using thermal and radar images, and disaster relief and monitoring.

XV-15 Tilt Rotor fly-by-wire collective control demonstrator development specifications

NASA Technical Reports Server (NTRS)

Meuleners, R. J.

1981-01-01

A fly by wire system in the collective control system for XV-15 Tilt Rotor Research Aircraft was evaluated. The collective control system was selected because it requires a system tracking accuracy between right and left rotors of approximately 0.1%. The performance characteristics of the collectors axel provide typical axis control response data. The demonstrator is bread boarded as a dual system instead of the triplex system.

Characterization of typical heavy metals in pyrolysis MSWI fly ash.

PubMed

Xu, Tengtun; Wang, Li'ao; Zeng, Yunmin; Zhao, Xue; Wang, Lei; Zhan, Xinyuan; Li, Tong; Yang, Lu

2018-06-07

Thermal treatment methods are used extensively in the process of municipal solid waste incineration fly ash. However, the characterization of heavy metals during this process should be understood more clearly in order to control secondary pollution. In this paper, the content, speciation and leaching toxicity of mercury (Hg), plumbum (Pb), cadmium (Cd) and zinc (Zn) in fly ash treated under different temperatures and time were firstly analysed as pre-tests. Later, pilot-scale pyrolysis equipment was used to explore the concentration and speciation changes in the heavy metals of fly ash. Finally, the phase constitution and microstructure changes in fly ash were compared before and after pyrolysis using X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The results showed that (a) The appropriate processing temperature was between 400°C and 450°C, and the processing time should be 1 h. (b) The stability of heavy metals in fly ash increased after pyrolysis. (c) XRD and SEM results indicated that phase constitution changed a little, but the microstructure varied to a porous structure similar to that of a coral reef after pyrolysis. These results suggest that pyrolysis could be an effective method in controlling heavy metal pollution in fly ash.

Impact of Airspace Charges on Transatlantic Aircraft Trajectories

NASA Technical Reports Server (NTRS)

Sridhar, Banavar; Ng, Hok K.; Linke, Florian; Chen, Neil Y.

2015-01-01

Aircraft flying over the airspace of different countries are subject to over-flight charges. These charges vary from country to country. Airspace charges, while necessary to support the communication, navigation and surveillance services, may lead to aircraft flying routes longer than wind-optimal routes and produce additional carbon dioxide and other gaseous emissions. This paper develops an optimal route between city pairs by modifying the cost function to include an airspace cost whenever an aircraft flies through a controlled airspace without landing or departing from that airspace. It is assumed that the aircraft will fly the trajectory at a constant cruise altitude and constant speed. The computationally efficient optimal trajectory is derived by solving a non-linear optimal control problem. The operational strategies investigated in this study for minimizing aircraft fuel burn and emissions include flying fuel-optimal routes and flying cost-optimal routes that may completely or partially reduce airspace charges en route. The results in this paper use traffic data for transatlantic flights during July 2012. The mean daily savings in over-flight charges, fuel cost and total operation cost during the period are 17.6 percent, 1.6 percent, and 2.4 percent respectively, along the cost- optimal trajectories. The transatlantic flights can potentially save $600,000 in fuel cost plus $360,000 in over-flight charges daily by flying the cost-optimal trajectories. In addition, the aircraft emissions can be potentially reduced by 2,070 metric tons each day. The airport pairs and airspace regions that have the highest potential impacts due to airspace charges are identified for possible reduction of fuel burn and aircraft emissions for the transatlantic flights. The results in the paper show that the impact of the variation in fuel price on the optimal routes is to reduce the difference between wind-optimal and cost-optimal routes as the fuel price increases. The

Full scale visualization of the wing tip vortices generated by a typical agricultural aircraft

NASA Technical Reports Server (NTRS)

Cross, E. J., Jr.; Bridges, P.; Brownlee, J. A.; Liningston, W. W.

1980-01-01

The trajectories of the wing tip vortices of a typical agricultural aircraft were experimentally determined by flight test. A flow visualization method, similar to the vapor screen method used in wind tunnels, was used to obtain trajectory data for a range of flight speeds, airplane configurations, and wing loadings. Detailed measurements of the spanwise surface pressure distribution were made for all test points. Further, a powered 1/8 scale model of the aircraft was designed, built, and used to obtain tip vortex trajectory data under conditions similar to that of the full-scale test. The effects of light wind on the vortices were demonstrated, and the interaction of the flap vortex and the tip vortex was clearly shown in photographs and plotted trajectory data.

Using Fly-By-Wire Technology in Future Models of the UH-60 and Other Rotary Wing Aircraft

NASA Technical Reports Server (NTRS)

Solem, Courtney K.

2011-01-01

Several fixed-winged airplanes have successfully used fly-by-wire (FBW) technology for the last 40 years. This technology is now beginning to be incorporated into rotary wing aircraft. By using FBW technology, manufacturers are expecting to improve upon the weight, maintenance time and costs, handling and reliability of the aircraft. Before mass production of this new system begins in new models such as the UH-60MU, testing must be conducted to insure the safety of this technology as well as to reassure others it will be worth the time and money to make such a dramatic change to a perfectly functional machine. The RASCAL JUH-60A has been modified for these purposes. This Black Hawk helicopter has already been equipped with the FBW technology and can be configured as a near perfect representation of the UH-60MU. Because both machines have very similar qualities, the data collected from the RASCAL can be used to make future decisions about the UH-60MU. The U.S. Army AFDD Flight Project Office oversees all the design modifications for every hardware system used in the RASCAL aircraft. This project deals with specific designs and analyses of unique RASCAL aircraft subsystems and their modifications to conduct flight mechanics research.

Fly-by-Wire Systems Enable Safer, More Efficient Flight

NASA Technical Reports Server (NTRS)

2012-01-01

Using the ultra-reliable Apollo Guidance Computer that enabled the Apollo Moon missions, Dryden Flight Research Center engineers, in partnership with industry leaders such as Cambridge, Massachusetts-based Draper Laboratory, demonstrated that digital computers could be used to fly aircraft. Digital fly-by-wire systems have since been incorporated into large airliners, military jets, revolutionary new aircraft, and even cars and submarines.

X-36 Tailless Fighter Agility Research Aircraft in flight

NASA Technical Reports Server (NTRS)

1997-01-01

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.

X-36 Tailless Fighter Agility Research Aircraft in flight

NASA Technical Reports Server (NTRS)

1997-01-01

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.

J-FLiC UAS Flights for Acoustic Testing Research

NASA Technical Reports Server (NTRS)

Motter, Mark A.; High, James W.

2016-01-01

The jet-powered flying testbed (J-FLiC) unmanned aircraft system (UAS) successfully completed twenty-six flights at Fort AP Hill, VA, from 27 August until September 3 2015, supporting tests of a microphone array system for aircraft noise measurement. The test vehicles, J-FLiC NAVY2 (N508NU), and J-FLiC 4 (N509NU), were flown under manual and autopiloted control in a variety of test conditions: clean at speeds ranging from 80 to 150 knots; and full landing configuration at speeds ranging from 50 to 95 knots. During the test campaign, autopilot capability was incrementally improved to ultimately provide a high degree of accuracy and repeatability of the critical test requirements for airspeed, altitude, runway alignment and position over the microphone array. Manual flights were performed for test conditions at the both ends of the speed envelope where autopiloted flight would have required flight beyond visual range and more extensive developmental work. The research objectives of the campaign were fully achieved. The ARMD Integrated Systems Research Program (ISRP) Environmentally Responsible Aviation (ERA) Project aims to develop the enabling capabilities/technologies that will allow prediction/reduction of aircraft noise. A primary measurement tool for ascertaining and characterizing empirically the effectiveness of various noise reduction technologies is a microphone phased array system. Such array systems need to be vetted and certified for operational use via field deployments and overflights of the array with test aircraft, in this case with sUAS aircraft such as J-FLiC.

Flight Tests of a Remaining Flying Time Prediction System for Small Electric Aircraft in the Presence of Faults

NASA Technical Reports Server (NTRS)

Hogge, Edward F.; Kulkarni, Chetan S.; Vazquez, Sixto L.; Smalling, Kyle M.; Strom, Thomas H.; Hill, Boyd L.; Quach, Cuong C.

2017-01-01

This paper addresses the problem of building trust in the online prediction of a battery powered aircraft's remaining flying time. A series of flight tests is described that make use of a small electric powered unmanned aerial vehicle (eUAV) to verify the performance of the remaining flying time prediction algorithm. The estimate of remaining flying time is used to activate an alarm when the predicted remaining time is two minutes. This notifies the pilot to transition to the landing phase of the flight. A second alarm is activated when the battery charge falls below a specified limit threshold. This threshold is the point at which the battery energy reserve would no longer safely support two repeated aborted landing attempts. During the test series, the motor system is operated with the same predefined timed airspeed profile for each test. To test the robustness of the prediction, half of the tests were performed with, and half were performed without, a simulated powertrain fault. The pilot remotely engages a resistor bank at a specified time during the test flight to simulate a partial powertrain fault. The flying time prediction system is agnostic of the pilot's activation of the fault and must adapt to the vehicle's state. The time at which the limit threshold on battery charge is reached is then used to measure the accuracy of the remaining flying time predictions. Accuracy requirements for the alarms are considered and the results discussed.

Detecting aircraft with a low-resolution infrared sensor.

PubMed

Jakubowicz, Jérémie; Lefebvre, Sidonie; Maire, Florian; Moulines, Eric

2012-06-01

Existing computer simulations of aircraft infrared signature (IRS) do not account for dispersion induced by uncertainty on input data, such as aircraft aspect angles and meteorological conditions. As a result, they are of little use to estimate the detection performance of IR optronic systems; in this case, the scenario encompasses a lot of possible situations that must be indeed addressed, but cannot be singly simulated. In this paper, we focus on low-resolution infrared sensors and we propose a methodological approach for predicting simulated IRS dispersion of poorly known aircraft and performing aircraft detection on the resulting set of low-resolution infrared images. It is based on a sensitivity analysis, which identifies inputs that have negligible influence on the computed IRS and can be set at a constant value, on a quasi-Monte Carlo survey of the code output dispersion, and on a new detection test taking advantage of level sets estimation. This method is illustrated in a typical scenario, i.e., a daylight air-to-ground full-frontal attack by a generic combat aircraft flying at low altitude, over a database of 90,000 simulated aircraft images. Assuming a white noise or a fractional Brownian background model, detection performances are very promising.

NASA's Zero-g aircraft operations

NASA Technical Reports Server (NTRS)

Williams, R. K.

1988-01-01

NASA's Zero-g aircraft, operated by the Johnson Space Center, provides the unique weightless or zero-g environment of space flight for hardware development and test and astronaut training purposes. The program, which began in 1959, uses a slightly modified Boeing KC-135A aircraft, flying a parabolic trajectory, to produce weightless periods of 20 to 25 seconds. The program has supported the Mercury, Gemini, Apollo, Skylab, Apollo-Soyuz and Shuttle programs as well as a number of unmanned space operations. Typical experiments for flight in the aircraft have included materials processing experiments, welding, fluid manipulation, cryogenics, propellant tankage, satellite deployment dynamics, planetary sciences research, crew training with weightless indoctrination, space suits, tethers, etc., and medical studies including vestibular research. The facility is available to microgravity research organizations on a cost-reimbursable basis, providing a large, hands-on test area for diagnostic and support equipment for the Principal Investigators and providing an iterative-type design approach to microgravity experiment development. The facility allows concepts to be proven and baseline experimentation to be accomplished relatively inexpensively prior to committing to the large expense of a space flight.

Learning to Fly.

ERIC Educational Resources Information Center

Weil, Patricia E.

1983-01-01

Presents information on where to learn to fly, which aircraft is best for this purpose, and approximate costs. Includes additional information on certificates, licenses, and ratings, and a description of the two phases of the General Aviation Manufacturers Association flight training program. (JN)

The conceptual design of a Mach 2 Oblique Flying Wing supersonic transport

NASA Technical Reports Server (NTRS)

Vandervelden, Alexander J. M.

1989-01-01

This paper is based on a performance and economics study of a Mach two oblique flying wing transport aircraft that is to replace the B747B. In order to fairly compare our configuration with the B747B an equal structural technology level is assumed. It will be shown that the oblique flying wing configuration will equal or outperform the B747 in speed, economy and comfort while a modern stability and control system will balance the aircraft and smooth out gusts. The aircraft is designed to comply with the FAR25 airworthiness requirements and FAR36 stage 3 noise regulations. Geometry, aerodynamics, stability and control parameters of the oblique flying wing transport are discussed.

Effect of time delay on flying qualities: An update

NASA Technical Reports Server (NTRS)

Smith, R. E.; Sarrafian, S. K.

1986-01-01

Flying qualities problems of modern, full-authority electronic flight control systems are most often related to the introduction of additional time delay in aircraft response to a pilot input. These delays can have a significant effect on the flying qualities of the aircraft. Time delay effects are reexamined in light of recent flight test experience with aircraft incorporating new technology. Data from the X-29A forward-swept-wing demonstrator, a related preliminary in-flight experiment, and other flight observations are presented. These data suggest that the present MIL-F-8785C allowable-control system time delay specifications are inadequate or, at least, incomplete. Allowable time delay appears to be a function of the shape of the aircraft response following the initial delay. The cockpit feel system is discussed as a dynamic element in the flight control system. Data presented indicate that the time delay associated with a significant low-frequency feel system does not result in the predicted degradation in aircraft flying qualities. The impact of the feel system is discussed from two viewpoints: as a filter in the control system which can alter the initial response shape and, therefore, the allowable time delay, and as a unique dynamic element whose delay contribution can potentially be discounted by special pilot loop closures.

Back symptoms in aviators flying different aircraft.

PubMed

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

2012-07-01

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

Northrop Grumman Corporation's modified U.S. Navy F-5E Shaped Sonic Boom Demonstration (SSBD) aircraft flies over Lake Isabella, Calif., on Aug. 4, 2003

NASA Image and Video Library

2003-08-04

Northrop Grumman Corporation's modified U.S. Navy F-5E Shaped Sonic Boom Demonstration (SSBD) aircraft flies over Lake Isabella, California on Aug. 4, 2003. NASA Dryden provided range, air and ground data-gathering support for the SSBD project, which is part of DARPA's Quiet Supersonic Platform (QSP) program.

Effect of multiple engine placement on aeroelastic trim and stability of flying wing aircraft

NASA Astrophysics Data System (ADS)

Mardanpour, Pezhman; Richards, Phillip W.; Nabipour, Omid; Hodges, Dewey H.

2014-01-01

Effects of multiple engine placement on flutter characteristics of a backswept flying wing resembling the HORTEN IV are investigated using the code NATASHA (Nonlinear Aeroelastic Trim And Stability of HALE Aircraft). Four identical engines with defined mass, inertia, and angular momentum are placed in different locations along the span with different offsets from the elastic axis while fixing the location of the aircraft c.g. The aircraft experiences body freedom flutter along with non-oscillatory instabilities that originate from flight dynamics. Multiple engine placement increases flutter speed particularly when the engines are placed in the outboard portion of the wing (60-70% span), forward of the elastic axis, while the lift to drag ratio is affected negligibly. The behavior of the sub- and supercritical eigenvalues is studied for two cases of engine placement. NATASHA captures a hump body-freedom flutter with low frequency for the clean wing case, which disappears as the engines are placed on the wings. In neither case is there any apparent coalescence between the unstable modes. NATASHA captures other non-oscillatory unstable roots with very small amplitude, apparently originating with flight dynamics. For the clean-wing case, in the absence of aerodynamic and gravitational forces, the regions of minimum kinetic energy density for the first and third bending modes are located around 60% span. For the second mode, this kinetic energy density has local minima around the 20% and 80% span. The regions of minimum kinetic energy of these modes are in agreement with calculations that show a noticeable increase in flutter speed if engines are placed forward of the elastic axis at these regions.

Flight deck magnetic fields in commercial aircraft.

PubMed

Nicholas, J S; Butler, G C; Lackland, D T; Hood, W C; Hoel, D G; Mohr, L C

2000-11-01

Airline pilots are exposed to magnetic fields generated by the aircraft's electrical system. The objectives of this study were (1) to directly measure flight deck magnetic fields in terms of personal exposure to the pilots when flying on different aircraft types over a 75-hour flight-duty month, and (2) to compare magnetic field exposures across flight deck types and job titles. Measurements were taken using personal dosimeters carried by either the Captain or the First Officer on Boeing 737/200, Boeing 747/400, Boeing 767/300ER, and Airbus 320 aircraft. Approximately 1,008 block hours were recorded at a sampling frequency of 3 seconds. Total block time exposure to the pilots ranged from a harmonic geometric mean of 6.7 milliGauss (mG) for the Boeing 767/300ER to 12.7 mG for the Boeing 737/200. Measured flight deck magnetic field levels were substantially above the 0.8-1 mG level typically found in the home or office and suggest the need for further study to evaluate potential health effects of long-term exposure. Copyright 2000 Wiley-Liss, Inc.

X-36 Tailless Fighter Agility Research Aircraft in flight

NASA Technical Reports Server (NTRS)

1997-01-01

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.

Longitudinal flying qualities criteria for single-pilot instrument flight operations

NASA Technical Reports Server (NTRS)

Stengel, R. F.; Bar-Gill, A.

1983-01-01

Modern estimation and control theory, flight testing, and statistical analysis were used to deduce flying qualities criteria for General Aviation Single Pilot Instrument Flight Rule (SPIFR) operations. The principal concern is that unsatisfactory aircraft dynamic response combined with high navigation/communication workload can produce problems of safety and efficiency. To alleviate these problems. The relative importance of these factors must be determined. This objective was achieved by flying SPIFR tasks with different aircraft dynamic configurations and assessing the effects of such variations under these conditions. The experimental results yielded quantitative indicators of pilot's performance and workload, and for each of them, multivariate regression was applied to evaluate several candidate flying qualities criteria.

Derivation and definition of a linear aircraft model

NASA Technical Reports Server (NTRS)

Duke, Eugene L.; Antoniewicz, Robert F.; Krambeer, Keith D.

1988-01-01

A linear aircraft model for a rigid aircraft of constant mass flying over a flat, nonrotating earth is derived and defined. The derivation makes no assumptions of reference trajectory or vehicle symmetry. The linear system equations are derived and evaluated along a general trajectory and include both aircraft dynamics and observation variables.

Shuttle Carrier Aircraft

NASA Image and Video Library

2014-04-23

It has been called the world's greatest piggyback ride: a space shuttle, atop a Boeing 747 jet aircraft. But this is no ordinary 747, this is the Shuttle Carrier Aircraft...the SCA. This specially modified jumbo jet was not only a taxi service for the shuttle, but also helped in the development of the shuttle itself. In 30 years of flying, the majestic image of a spacecraft joined to the SCA, became a symbol of American invention and ingenuity.

Computers Take Flight: A History of NASA's Pioneering Digital Fly-By-Wire Project

NASA Technical Reports Server (NTRS)

Tomayko, James E.

2000-01-01

An overview of the NASA F-8 Fly-by Wire project is presented. The project made two significant contributions to the new technology: (1) a solid design base of techniques that work and those that do not, and (2) credible evidence of good flying qualities and the ability of such a system to tolerate real faults and to continue operation without degradation. In 1972 the F-8C aircraft used in the program became he first digital fly-by-wire aircraft to operate without a mechanical backup system.

Flight-Effects on Predicted Fan Fly-By Noise

NASA Technical Reports Server (NTRS)

Heidmann, M. F.; Clark, B. J.

1977-01-01

The impact on PNLT (Perceived Noise Level, Tone corrected) and Fly-by EPNL (Effective Perceived Noise Level) when forward motion reduces the noise generated by the bypass fan of an aircraft engine was studied. Calculated noise spectra for a typical subsonic tip speed fan designed for blade passage frequency (BPF) tone cutoff were translated in frequency by systematically varying the BPF from 0.5 to 8 kHz. Two cases of predicted flight-effects on fan source noises were considered: reduced BPF tone level of 8 db and reduced broadband noise level of about 2 db in addition to reduced tone level. The maximum reduction in PNLT of the noise as emitted from the fan occurred when the BPF was at 4 kHz where the reductions were 7.4 and 10.0 db. The maximum reduction in EPNL of the noise as received during a 500-foot altitude fly-by occurred when the BPF was at 2.5 kHz where the reductions were 5.0 and 7.8 db.

Current Methods Modeling and Simulating Icing Effects on Aircraft Performance, Stability, Control

NASA Technical Reports Server (NTRS)

Ratvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam

2010-01-01

Icing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to the performance changes, icing can also affect control surface effectiveness, hinge moments, and damping. These effects result in altered aircraft stability and control and flying qualities. Over the past 80 years, methods have been developed to understand how icing affects performance, stability, and control. Emphasis has been on wind-tunnel testing of two-dimensional subscale airfoils with various ice shapes to understand their effect on the flowfield and ultimately the aerodynamics. This research has led to wind-tunnel testing of subscale complete aircraft models to identify the integrated effects of icing on the aircraft system in terms of performance, stability, and control. Data sets of this nature enable pilot-in-the-loop simulations to be performed for pilot training or engineering evaluation of system failure impacts or control system design.

Lockheed ER-2 #806 high altitude research aircraft in flight

NASA Image and Video Library

1998-11-17

ER-2 tail number 806, is one of two Airborne Science ER-2s used as science platforms by Dryden. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, the ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

Lockheed ER-2 #809 high altitude research aircraft in flight

NASA Image and Video Library

2001-08-01

ER-2 tail number 809, is one of two Airborne Science ER-2s used as science platforms by Dryden. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, the ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

Lockheed ER-2 #806 high altitude research aircraft during landing

NASA Image and Video Library

1998-12-18

ER-2 tail number 806, is one of two Airborne Science ER-2s used as science platforms by Dryden. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, the ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet. The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F-118 turbofan engine rated at 17,000 pounds thrust powers the ER-2.

The practical difficulties of commercial flying

NASA Technical Reports Server (NTRS)

Courtney, F T

1924-01-01

This paper relates some of the problems commercial aircraft companies have in attracting larger numbers of paying customers. The author discusses some remedies such as changing the public perception of flying as dangerous.

Flying qualities - A costly lapse in flight-control design

NASA Technical Reports Server (NTRS)

Berry, D. T.

1982-01-01

Generic problems in advanced aircraft with advanced control systems which suffer from control sensitivity, sluggish response, and pilot-induced oscillation tendencies are examined, with a view to improving techniques for eliminating the problems in the design phase. Results of two NASA and NASA/AIAA workshops reached a consensus that flying qualities criteria do not match control system development, control system designers are not relying on past experience in their field, ground-based simulation is relied on too heavily, and communications between flying qualities and control systems engineers need improvement. A summation is offered in that hardware and software have outstripped the pilot's capacity to use the capabilities which new aircraft offer. The flying qualities data base is stressed to be dynamic, and continually redefining the man/machine relationships.

Interaction of Aircraft Wakes From Laterally Spaced Aircraft

NASA Technical Reports Server (NTRS)

Proctor, Fred H.

2009-01-01

Large Eddy Simulations are used to examine wake interactions from aircraft on closely spaced parallel paths. Two sets of experiments are conducted, with the first set examining wake interactions out of ground effect (OGE) and the second set for in ground effect (IGE). The initial wake field for each aircraft represents a rolled-up wake vortex pair generated by a B-747. Parametric sets include wake interactions from aircraft pairs with lateral separations of 400, 500, 600, and 750 ft. The simulation of a wake from a single aircraft is used as baseline. The study shows that wake vortices from either a pair or a formation of B-747 s that fly with very close lateral spacing, last longer than those from an isolated B-747. For OGE, the inner vortices between the pair of aircraft, ascend, link and quickly dissipate, leaving the outer vortices to decay and descend slowly. For the IGE scenario, the inner vortices ascend and last longer, while the outer vortices decay from ground interaction at a rate similar to that expected from an isolated aircraft. Both OGE and IGE scenarios produce longer-lasting wakes for aircraft with separations less than 600 ft. The results are significant because concepts to increase airport capacity have been proposed that assume either aircraft formations and/or aircraft pairs landing on very closely spaced runways.

Pilot response to peripheral vision cues during instrument flying tasks.

DOT National Transportation Integrated Search

1968-02-01

In an attempt to more closely associate the visual aspects of instrument flying with that of contact flight, a study was made of human response to peripheral vision cues relating to aircraft roll attitude. Pilots, ranging from 52 to 12,000 flying hou...

Flight-test evaluation of STOL control and flight director concepts in a powered-lift aircraft flying curved decelerating approaches

NASA Technical Reports Server (NTRS)

Hindson, W. S.; Hardy, G. H.; Innis, R. C.

1981-01-01

Flight tests were carried out to assess the feasibility of piloted steep curved, and decelerating approach profiles in powered lift STOL aircraft. Several STOL control concepts representative of a variety of aircraft were evaluated in conjunction with suitably designed flight directions. The tests were carried out in a real navigation environment, employed special electronic cockpit displays, and included the development of the performance achieved and the control utilization involved in flying 180 deg turning, descending, and decelerating approach profiles to landing. The results suggest that such moderately complex piloted instrument approaches may indeed be feasible from a pilot acceptance point of view, given an acceptable navigation environment. Systems with the capability of those used in this experiment can provide the potential of achieving instrument operations on curved, descending, and decelerating landing approaches to weather minima corresponding to CTOL Category 2 criteria, while also providing a means of realizing more efficient operations during visual flight conditions.

Human factors of advanced technology (glass cockpit) transport aircraft

NASA Technical Reports Server (NTRS)

Wiener, Earl L.

1989-01-01

A three-year study of airline crews at two U.S. airlines who were flying an advanced technology aircraft, the Boeing 757 is discussed. The opinions and experiences of these pilots as they view the advanced, automated features of this aircraft, and contrast them with previous models they have flown are discussed. Training for advanced automation; (2) cockpit errors and error reduction; (3) management of cockpit workload; and (4) general attitudes toward cockpit automation are emphasized. The limitations of the air traffic control (ATC) system on the ability to utilize the advanced features of the new aircraft are discussed. In general the pilots are enthusiastic about flying an advanced technology aircraft, but they express mixed feelings about the impact of automation on workload, crew errors, and ability to manage the flight.

Real-Time Global Nonlinear Aerodynamic Modeling for Learn-To-Fly

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

2016-01-01

Flight testing and modeling techniques were developed to accurately identify global nonlinear aerodynamic models for aircraft in real time. The techniques were developed and demonstrated during flight testing of a remotely-piloted subscale propeller-driven fixed-wing aircraft using flight test maneuvers designed to simulate a Learn-To-Fly scenario. Prediction testing was used to evaluate the quality of the global models identified in real time. The real-time global nonlinear aerodynamic modeling algorithm will be integrated and further tested with learning adaptive control and guidance for NASA Learn-To-Fly concept flight demonstrations.

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

NASA Technical Reports Server (NTRS)

1996-01-01

,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.

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

NASA Technical Reports Server (NTRS)

1996-01-01

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.

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

NASA Technical Reports Server (NTRS)

1996-01-01

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.

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

NASA Technical Reports Server (NTRS)

1996-01-01

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.

Overview of Propulsion Systems for a Mars Aircraft

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.; Miller, Christopher J.; Reed, Brian D.; Kohout, Lisa L.; Loyselle, Patricia L.

2001-01-01

The capabilities and performance of an aircraft depends greatly on the ability of the propulsion system to provide thrust. Since the beginning of powered flight, performance has increased in step with advancements in aircraft propulsion systems. These advances in technology from combustion engines to jets and rockets have enabled aircraft to exploit our atmospheric environment and fly at altitudes near the Earth's surface to near orbit at speeds ranging from hovering to several times the speed of sound. One of the main advantages of our atmosphere for these propulsion systems is the availability of oxygen. Getting oxygen basically "free" from the atmosphere dramatically increases the performance and capabilities of an aircraft. This is one of the reasons our present-day aircraft can perform such a wide range of tasks. But this advantage is limited to Earth; if we want to fly an aircraft on another planetary body, such as Mars, we will either have to carry our own source of oxygen or use a propulsion system that does not require it. The Mars atmosphere, composed mainly of carbon dioxide, is very thin. Because of this low atmospheric density, an aircraft flying on Mars will most likely be operating, in aerodynamical terms, within a very low Reynolds number regime. Also, the speed of sound within the Martian environment is approximately 20 percent less than it is on Earth. The reduction in the speed of sound plays an important role in the aerodynamic performance of both the aircraft itself and the components of the propulsion system, such as the propeller. This low Reynolds number-high Mach number flight regime is a unique flight environment that is very rarely encountered here on Earth.

75 FR 9327 - Aircraft Noise Certification Documents for International Operations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-02

... in 14 CFR part 91 Aircraft, Noise control, Reporting and recordkeeping requirements. The Amendment 0...; Amendment No. 91-312] RIN 2120-AJ31 Aircraft Noise Certification Documents for International Operations... operating rules to require U.S. operators flying outside the United States to carry aircraft noise...

Northrop Grumman Corporation's modified U.S. Navy F-5E Shaped Sonic Boom Demonstration (SSBD) aircraft flies over the company's Palmdale, Calif. facilities on Aug. 2, 2003

NASA Image and Video Library

2003-08-02

Northrop Grumman Corporation's modified U.S. Navy F-5E Shaped Sonic Boom Demonstration (SSBD) aircraft flies over the company's Palmdale, California facilities on Aug. 2, 2003. NASA Dryden provided range, air and ground data-gathering support for the SSBD project, which is part of DARPA's Quiet Supersonic Platform (QSP) program.

YO-3A acoustics research aircraft systems manual

NASA Technical Reports Server (NTRS)

Cross, J. L.

1984-01-01

The flight testing techniques, equipment, and procedures employed during air-to-air acoustic testing of helicopters using the NASA YO-3A Acoustic Research Aircraft are discussed. The research aircraft instrumentation system is described as well as hardware installation on the test aircraft and techniques used during the tests. Emphasis is placed on formation flying, position locations, test matrices, and test procedures.

Combining tracer flux ratio methodology with low-flying aircraft measurements to estimate dairy farm CH4 emissions

NASA Astrophysics Data System (ADS)

Daube, C.; Conley, S.; Faloona, I. C.; Yacovitch, T. I.; Roscioli, J. R.; Morris, M.; Curry, J.; Arndt, C.; Herndon, S. C.

2017-12-01

Livestock activity, enteric fermentation of feed and anaerobic digestion of waste, contributes significantly to the methane budget of the United States (EPA, 2016). Studies question the reported magnitude of these methane sources (Miller et. al., 2013), calling for more detailed research of agricultural animals (Hristov, 2014). Tracer flux ratio is an attractive experimental method to bring to this problem because it does not rely on estimates of atmospheric dispersion. Collection of data occurred during one week at two dairy farms in central California (June, 2016). Each farm varied in size, layout, head count, and general operation. The tracer flux ratio method involves releasing ethane on-site with a known flow rate to serve as a tracer gas. Downwind mixed enhancements in ethane (from the tracer) and methane (from the dairy) were measured, and their ratio used to infer the unknown methane emission rate from the farm. An instrumented van drove transects downwind of each farm on public roads while tracer gases were released on-site, employing the tracer flux ratio methodology to assess simultaneous methane and tracer gas plumes. Flying circles around each farm, a small instrumented aircraft made measurements to perform a mass balance evaluation of methane gas. In the course of these two different methane quantification techniques, we were able to validate yet a third method: tracer flux ratio measured via aircraft. Ground-based tracer release rates were applied to the aircraft-observed methane-to-ethane ratios, yielding whole-site methane emission rates. Never before has the tracer flux ratio method been executed with aircraft measurements. Estimates from this new application closely resemble results from the standard ground-based technique to within their respective uncertainties. Incorporating this new dimension to the tracer flux ratio methodology provides additional context for local plume dynamics and validation of both ground and flight-based data.

A flight test method for pilot/aircraft analysis

NASA Technical Reports Server (NTRS)

Koehler, R.; Buchacker, E.

1986-01-01

In high precision flight maneuvres a pilot is a part of a closed loop pilot/aircraft system. The assessment of the flying qualities is highly dependent on the closed loop characteristics related to precision maneuvres like approach, landing, air-to-air tracking, air-to-ground tracking, close formation flying and air-to air refueling of the receiver. The object of a research program at DFVLR is the final flight phase of an air to ground mission. In this flight phase the pilot has to align the aircraft with the target, correct small deviations from the target direction and keep the target in his sights for a specific time period. To investigate the dynamic behavior of the pilot-aircraft system a special ground attack flight test technique with a prolonged tracking maneuvres was developed. By changing the targets during the attack the pilot is forced to react continously on aiming errors in his sights. Thus the closed loop pilot/aircraft system is excited over a wide frequency range of interest, the pilot gets more information about mission oriented aircraft dynamics and suitable flight test data for a pilot/aircraft analysis can be generated.

PTERA - Modular Aircraft Flight Test

NASA Image and Video Library

2016-01-13

Aerospace testing can be costly and time consuming but a new modular, subscale remotely piloted aircraft offers NASA researchers more affordable options for developing a wide range of cutting edge aviation and space technologies. The Prototype-Technology Evaluation and Research Aircraft (PTERA), developed by Area-I, Inc., of Kennesaw, Georgia, is an extremely versatile and high quality, yet inexpensive, flying laboratory bridging the gap between wind tunnels and crewed flight testing.

Static Aeroelasticity in Combat Aircraft.

DTIC Science & Technology

1986-01-01

stiffness scaled beam machined along a predicted elastic axis, and load iola- tion cuts forward and aft of the beam, has proved to be most successful...aircraft components. Many papers deal with the activities in the field of structural optimization.’ 4sing fiber composites , a new design technique...Supersonic Design Composite Structures Fly - by - Wire Thin Profiles Aeroelastic Tailoring Unstable Aircraft V Variable Camber Lght Weight Pilot Handling

Development of flying qualities criteria for single pilot instrument flight operations

NASA Technical Reports Server (NTRS)

Bar-Gill, A.; Nixon, W. B.; Miller, G. E.

1982-01-01

Flying qualities criteria for Single Pilot Instrument Flight Rule (SPIFR) operations were investigated. The ARA aircraft was modified and adapted for SPIFR operations. Aircraft configurations to be flight-tested were chosen and matched on the ARA in-flight simulator, implementing modern control theory algorithms. Mission planning and experimental matrix design were completed. Microprocessor software for the onboard data acquisition system was debugged and flight-tested. Flight-path reconstruction procedure and the associated FORTRAN program were developed. Algorithms associated with the statistical analysis of flight test results and the SPIFR flying qualities criteria deduction are discussed.

Current Methods for Modeling and Simulating Icing Effects on Aircraft Performance, Stability and Control

NASA Technical Reports Server (NTRS)

Ralvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam

2008-01-01

Icing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to the performance changes, icing can also affect control surface effectiveness, hinge moments, and damping. These effects result in altered aircraft stability and control and flying qualities. Over the past 80 years, methods have been developed to understand how icing affects performance, stability and control. Emphasis has been on wind tunnel testing of two-dimensional subscale airfoils with various ice shapes to understand their effect on the flow field and ultimately the aerodynamics. This research has led to wind tunnel testing of subscale complete aircraft models to identify the integrated effects of icing on the aircraft system in terms of performance, stability, and control. Data sets of this nature enable pilot in the loop simulations to be performed for pilot training, or engineering evaluation of system failure impacts or control system design.

Aircraft

DOEpatents

Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

1998-01-01

This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

Aircraft

DOEpatents

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

1998-09-22

This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

Measurement of Altitude in Blind Flying

NASA Technical Reports Server (NTRS)

Brombacher, W G

1934-01-01

In this note, instruments for measuring altitude and rate of change of altitude in blind flying and landing of aircraft and their performance are discussed. Of those indicating the altitude above ground level, the sonic altimeter is the most promising. Its present bulk, intermittent operation, and more or less unsatisfactory means of indication are serious drawbacks to its use. The sensitive type aneroid altimeter is also discussed and errors in flying at a pressure level and in landing are discussed in detail.

The F-18 systems research aircraft facility

NASA Technical Reports Server (NTRS)

Sitz, Joel R.

1992-01-01

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.

Real time aircraft fly-over noise discrimination

NASA Astrophysics Data System (ADS)

Genescà, M.; Romeu, J.; Pàmies, T.; Sánchez, A.

2009-06-01

A method for measuring aircraft noise time history with automatic elimination of simultaneous urban noise is presented in this paper. A 3 m-long 12-microphone sparse array has been proven to give good performance in a wide range of urban placements. Nowadays, urban placements have to be avoided because their background noise has a great influence on the measurements made by sound level meters or single microphones. Because of the small device size and low number of microphones (that make it so easy to set up), the resolution of the device is not high enough to provide a clean aircraft noise time history by only applying frequency domain beamforming to the spatial cross-correlations of the microphones' signals. Therefore, a new step to the processing algorithm has been added to eliminate this handicap.

A Blanik L-23 glider carrying a microphone and a pressure transducer flies near a BADS sensor following flight under the path of the F-5E SSBE aircraft

NASA Image and Video Library

2004-01-13

A United States Air Force Test Pilot School Blanik L-23 glider carrying a microphone and a pressure transducer flies near a BADS (Boom Amplitudes Direction System) sensor following flight at an altitude of 10 thousand feet under the path of the F-5E SSBE aircraft. The SSBE (Shaped Sonic Boom Experiment) was formerly known as the Shaped Sonic Boom Demonstration, or SSBD, and is part of DARPA's Quiet Supersonic Platform (QSP) program. On August 27, 2003, the F-5E SSBD aircraft demonstrated a method to reduce the intensity of sonic booms.

Safety Passage in the Flying Canoes

NASA Technical Reports Server (NTRS)

1984-01-01

Jungle Aviation and Radio Service (JAARS) delivers missionaries to remote outposts under sometimes hazardous flying conditions. A serious accident led JAARS' to initiate a crash survivability research program based on NASA technology. In 1978, JAARS sought help from Langley Research Center and was invited to participate in Langley's crashworthiness program. With assistance from Langley, JAARS developed an impact absorbing aircraft seat designed to minimize crash injury. The seat design is available to all missionary aircraft and JAARS is offering it for commercial manufacture.

Dabbling duck behavior and aircraft activity in coastal North Carolina

USGS Publications Warehouse

Conomy, J.T.; Collazo, J.A.; Dubovsky, J.A.; Fleming, W.J.

1998-01-01

Requests to increase military aircraft activity in some training facilities in the United States have prompted the need to determine if waterfowl and other wildlife are adversely affected by aircraft disturbance. We quantified behavioral responses of wintering American black ducks (Anas rubripes), American wigeon (A. americana), gadwall (A. strepera), and American green-winged teal (A. crecca carolinensis) exposed to low-level flying military aircrafts at Piney and Cedar islands, North Carolina, in 1991 and 1992. Waterfowl spent ???1.4% of their time responding to aircraft, which included flying, swimming, and alert behaviors. Mean duration of responses by species ranged from 10 to 40 sec. Costs to each species were deemed low because disruptions represented a low percentage of their time-activity budgets only a small proportion of birds reacted to disturbance (13/672; 2%); and the likelihood of resuming the activity disrupted by an aircraft disturbance event was high (64%). Recorded levels of aircraft disturbance (i.e., x?? = 85.1 dBA) were not adversely affecting the time-activity budgets of selected waterfowl species wintering at Piney and Cedar islands.

Investigations of simulated aircraft flight through thunderstorm outflows

NASA Technical Reports Server (NTRS)

Frost, W.; Crosby, B.

1978-01-01

The effects of wind shear on aircraft flying through thunderstorm gust fronts were investigated. A computer program was developed to solve the two dimensional, nonlinear equations of aircraft motion, including wind shear. The procedure described and documented accounts for spatial and temporal variations of the aircraft within the flow regime. Analysis of flight paths and control inputs necessary to maintain specified trajectories for aircraft having characteristics of DC-8, B-747, augmentor wing STOL, and DHC-6 aircraft was recorded. From the analysis an attempt was made to find criteria for reduction of the hazards associated with landing through thunderstorm gust fronts.

Dynamics of the aircraft in a vortex wake

NASA Astrophysics Data System (ADS)

Gaifullin, A. M.; Sviridenko, Yu N.

2018-03-01

This paper considers the aerodynamics and the dynamics of an aircraft on various modes when the aircraft enters a strongly swirling flow. This is the case when an aircraft purposefully enters the jet-vortex wake of another aircraft in the course of in-flight refuelling, when an aircraft is flying in the trail of an aircraft carrier during landing, or when an aircraft accidentally enters other aircrafts’ vortex wakes. These situations, according to pilots’ evaluation, are the most dangerous and the most difficult modes for piloting. That is why their real time modelling on flight simulators has taken on particular importance. This article provides the algorithms and methodology of mathematical modelling of aerodynamic forces and moments which act upon an aircraft in vortex wakes.

Process for Refining and Validating a Finite Element Model of an Experimental High-Altitude, Long-Endurance (HALE) Aircraft

DTIC Science & Technology

2011-06-01

7 Figure 4. Helios flying near the Hawaiian islands of Niihau and Lehua [15] ................... 8 Figure 5. Plan view of ERAST Program aircraft...Figure 4. Helios flying near the Hawaiian islands of Niihau and Lehua [15] 9 Figure 5. Plan view of ERAST Program aircraft

Arctic regional methane fluxes by ecotope as derived using eddy covariance from a low-flying aircraft

NASA Astrophysics Data System (ADS)

Sayres, David S.; Dobosy, Ronald; Healy, Claire; Dumas, Edward; Kochendorfer, John; Munster, Jason; Wilkerson, Jordan; Baker, Bruce; Anderson, James G.

2017-07-01

The Arctic terrestrial and sub-sea permafrost region contains approximately 30 % of the global carbon stock, and therefore understanding Arctic methane emissions and how they might change with a changing climate is important for quantifying the global methane budget and understanding its growth in the atmosphere. Here we present measurements from a new in situ flux observation system designed for use on a small, low-flying aircraft that was deployed over the North Slope of Alaska during August 2013. The system combines a small methane instrument based on integrated cavity output spectroscopy (ICOS) with an air turbulence probe to calculate methane fluxes based on eddy covariance. We group surface fluxes by land class using a map based on LandSat Thematic Mapper (TM) data with 30 m resolution. We find that wet sedge areas dominate the methane fluxes with a mean flux of 2.1 µg m-2 s-1 during the first part of August. Methane emissions from the Sagavanirktok River have the second highest at almost 1 µg m-2 s-1. During the second half of August, after soil temperatures had cooled by 7 °C, methane emissions fell to between 0 and 0.5 µg m-2 s-1 for all areas measured. We compare the aircraft measurements with an eddy covariance flux tower located in a wet sedge area and show that the two measurements agree quantitatively when the footprints of both overlap. However, fluxes from sedge vary at times by a factor of 2 or more even within a few kilometers of the tower demonstrating the importance of making regional measurements to map out methane emissions spatial heterogeneity. Aircraft measurements of surface flux can play an important role in bridging the gap between ground-based measurements and regional measurements from remote sensing instruments and models.

Physiological responses of pilots to severe weather flying.

DOT National Transportation Integrated Search

1966-07-01

Selected measurements of stress-related and other physiological variables were made on jet aircraft pilots participating in USWB-NSSL turbulent weather programs. Data were gathered from two categories of flying conditions: (1) storm penetration fligh...

Integrated controls for a new aircraft generation

NASA Technical Reports Server (NTRS)

Mace, W. D.; Howell, W. E.

1978-01-01

Many of the commercial aircraft now flying will have to be phased out in the early 1980s because of fuel inefficiency and unacceptable noise levels. This paper discusses the role of new digital technology in making aircraft more fuel efficient, more reliable, and quieter. Attention is given to the integration of sensing and control functions in an aircraft in order to provide a simple, lightweight, and high-redundancy system. Technology under development now is expected to come on-line in the 1990s.

Assessment of flying-quality criteria for air-breathing aerospacecraft

NASA Technical Reports Server (NTRS)

Mcruer, Duane T.; Myers, Thomas T.; Hoh, Roger H.; Ashkenas, Irving L.; Johnston, Donald E.

1992-01-01

A study of flying quality requirements for air breathing aerospacecraft gives special emphasis to the unusual operational requirements and characteristics of these aircraft, including operation at hypersonic speed. The report considers distinguishing characteristics of these vehicles, including dynamic deficiencies and their implications for control. Particular emphasis is given to the interaction of the airframe and propulsion system, and the requirements for dynamic systems integration. Past operational missions are reviewed to define tasks and maneuvers to be considered for this class of aircraft. Areas of special concern with respect to vehicle dynamics and control are identified. Experience with the space shuttle orbiter is reviewed with respect to flight control system mechanization and flight experience in approach and landing flying qualities for the National Aerospace Plane (NASP).

Space Shuttle Discovery DC Fly-Over

NASA Image and Video Library

2012-04-17

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA), flies over the Washington skyline as seen from a NASA T-38 aircraft, Tuesday, April 17, 2012. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Robert Markowitz)

NASA S-3 Viking Aircraft

NASA Image and Video Library

2010-04-07

This photo shows NASA Glenn’s S-3 Viking Aircraft flying over downtown Cleveland, Ohio. The S-3 continues to conduct important research including regular flights over Lake Erie and other waterways to image algal blooms that have plagued the area’s waters.

Prospective communications research to support fly by light/power by wire

NASA Technical Reports Server (NTRS)

Game, David

1994-01-01

A NASA Research Grant NAG-1-1309, Distributed Fiber Optic Systems for Commercial Aircraft, was awarded during July 1991. This report primarily constitutes a summary of findings of the original background research done at that time. NASA is embarking on a research project to design the next generation of commercial aircraft, fly by light/power by wire. The objectives of this effort are to improve commercial aircraft design by (1) reducing the weight of the aircraft to improve efficiency and (2) improving the fault tolerance and safety of the aircraft by enhancing current systems with new technologies or introducing new systems into the aircraft.

Experiments Result in Safer, Spin-Resistant Aircraft

NASA Technical Reports Server (NTRS)

2014-01-01

The General Aviation Spin Program at Langley Research Center devised the first-of-their-kind guidelines for designing more spin-resistant aircraft. Thanks to NASA's contributions, the Federal Aviation Administration introduced the Part 23 spin-resistance standard in 1991. Los Angeles-based ICON Aircraft has now manufactured a new plane for consumer recreational flying that meets the complete set of criteria specified for Part 23 testing.

Flying an Autonomous Formation Flight mission, two F/A-18s from the NASA Dryden Flight Research Cent

NASA Technical Reports Server (NTRS)

2001-01-01

Flying an Autonomous Formation Flight mission, two F/A-18's from the NASA Dryden Flight Research Center, Edwards, California, gain altitude near Rogers Dry Lake. The Systems Research Aircraft (tail number 845) and F/A-18 tail number 847 are flying the second phase of a project that is demonstrating a 15-percent fuel savings of the trailing aircraft during cruise flight. Project goal was a 10-percent savings. The drag-reduction study mimics the formation of migrating birds. Scientists have known for years that the trailing birds require less energy than flying solo.

Multibody aircraft study, volume 2

NASA Technical Reports Server (NTRS)

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

1981-01-01

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.

Multibody aircraft study, volume 1

NASA Technical Reports Server (NTRS)

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

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.

NASA Dryden's two T-38A mission support aircraft fly in tight formation while conducting a pitot-static airspeed calibration check near Edwards Air Force Base

NASA Image and Video Library

2007-09-26

NASA Dryden Flight Research Center's two T-38A Talon mission support aircraft flew together for the first time on Sept. 26, 2007 while conducting pitot-static airspeed calibration checks during routine pilot proficiency flights. The two aircraft, flown by NASA research pilots Kelly Latimer and Frank Batteas, joined up with a NASA Dryden F/A-18 flown by NASA research pilot Dick Ewers to fly the airspeed calibrations at several speeds and altitudes that would be flown by the Stratospheric Observatory for Infrared Astronomy (SOFIA) Boeing 747SP during its initial flight test phase. The T-38s, along with F/A-18s, serve in a safety chase role during those test missions, providing critical instrument and visual monitoring for the flight test series.

High angle of attack flying qualities criteria for longitudinal rate command systems

NASA Technical Reports Server (NTRS)

Wilson, David J.; Citurs, Kevin D.; Davidson, John B.

1994-01-01

This study was designed to investigate flying qualities requirements of alternate pitch command systems for fighter aircraft at high angle of attack. Flying qualities design guidelines have already been developed for angle of attack command systems at 30, 45, and 60 degrees angle of attack, so this research fills a similar need for rate command systems. Flying qualities tasks that require post-stall maneuvering were tested during piloted simulations in the McDonnell Douglas Aerospace Manned Air Combat Simulation facility. A generic fighter aircraft model was used to test angle of attack rate and pitch rate command systems for longitudinal gross acquisition and tracking tasks at high angle of attack. A wide range of longitudinal dynamic variations were tested at 30, 45, and 60 degrees angle of attack. Pilot comments, Cooper-Harper ratings, and pilot induced oscillation ratings were taken from five pilots from NASA, USN, CAF, and McDonnell Douglas Aerospace. This data was used to form longitudinal design guidelines for rate command systems at high angle of attack. These criteria provide control law design guidance for fighter aircraft at high angle of attack, low speed flight conditions. Additional time history analyses were conducted using the longitudinal gross acquisition data to look at potential agility measures of merit and correlate agility usage to flying qualities boundaries. This paper presents an overview of this research.

The Development of a Highly Reliable Power Management and Distribution System for Civil Transport Aircraft

NASA Technical Reports Server (NTRS)

Coleman, Anthony S.; Hansen, Irving G.

1994-01-01

NASA is pursuing a program in Advanced Subsonic Transport (AST) to develop the technology for a highly reliable Fly-By-Light/Power-By-WIre aircraft. One of the primary objectives of the program is to develop the technology base for confident application of integrated PBW components and systems to transport aircraft to improve operating reliability and efficiency. Technology will be developed so that the present hydraulic and pneumatic systems of the aircraft can be systematically eliminated and replaced by electrical systems. These motor driven actuators would move the aircraft wing surfaces as well as the rudder to provide steering controls for the pilot. Existing aircraft electrical systems are not flight critical and are prone to failure due to Electromagnetic Interference (EMI) (1), ground faults and component failures. In order to successfully implement electromechanical flight control actuation, a Power Management and Distribution (PMAD) System must be designed having a reliability of 1 failure in 10(exp +9) hours, EMI hardening and a fault tolerance architecture to ensure uninterrupted power to all aircraft flight critical systems. The focus of this paper is to analyze, define, and describe technically challenging areas associated with the development of a Power By Wire Aircraft and typical requirements to be established at the box level. The authors will attempt to propose areas of investigation, citing specific military standards and requirements that need to be revised to accommodate the 'More Electric Aircraft Systems'.

Grob aircraft construction: The G 110 flies

NASA Technical Reports Server (NTRS)

Malzbender, B.

1982-01-01

Description, specifications and test flight performance of the G 110 are provided. The G 110 completely incorporates modern GfK construction techniques which heretofore have been developed and perfected for the construction of sailplanes. The G 110 is a prototype of a GfK constructed motorized aircraft and shows much promise for the future of German aviation.

VENUS Atmospheric Exploration by Solar Aircraft

NASA Astrophysics Data System (ADS)

Landis, G. A.; Lamarre, C.; Colozza, A.

2002-01-01

much easier than on planets such as Mars. Above the clouds, solar energy is available in abundance on Venus. Venus has a solar flux of 2600 W/m2, compared to Earth's 1370 W/m2. The solar intensity is 20 to 50% of the exoatmospheric intensity (depending on wavelength) at the bottom of the cloud layer at 50 km, and increases to nearly 95% of the exoatmospheric intensity at 65 km, the top of the main cloud layer, and the slow rotation of Venus allows an airplane to be designed for flight within continuous sunlight, eliminating the need for energy storage for nighttime flight. challenge for a Venus aircraft will be the fierce winds and caustic atmosphere. The wind reaches a speed of about 95m/s at the cloud top level, and in order to remain on the sunlit side of Venus, an exploration aircraft will have to be capable of sustained flight at or above the wind speed. desirable that the number of moving parts be minimized. Figure 1 shows a concept for a Venus airplane design that requires only two folds to fold the wing into an aeroshell, and no folds to deploy the tail. Because of the design constraint that the two- fold wing is to fit into a small aeroshell, the wing area is maximum at extremely low aspect ratio, and higher aspect ratios can be achieved only by reducing the wing area. To fit the circular aeroshell, the resulting design trade-off increases wing area by accepting the design compromise of an extremely short tail moment and small tail area (stabilizer area 9% of wing area). In terms of flight behavior, the aircraft is essentially a flying wing design with the addition of a small control surface. A more conventional aircraft design can be made by folding or telescoping the tail boom as well as the wing. Typical flight altitudes for analysis were 65 to 75 km above the surface. For exploration of lower altitudes, it is feasible to glide down to low altitudes for periods of several hours, accepting the fact that the airplane ground track will blow downwind, and

Aptitude and Trait Predictors of Manned and Unmanned Aircraft Pilot Job Performance

DTIC Science & Technology

2016-04-22

actually fly RPAs. To address this gap, the present study evaluated pre-accession trait (Big Five personality domains) and aptitude (spatial...knowledge, and personality traits that predict successful job performance for manned aircraft pilots also predict successful job performance for RPA...aptitude and personality traits , job performance, remotely-piloted aircraft, unmanned aircraft systems 16. SECURITY CLASSIFICATION OF: 17

Cost Avoidance Techniques for RC-135 Program Flying Training

DTIC Science & Technology

2013-06-01

135, age has an even greater impact . Built in the 1960’s, RC-135s have covered tours 8 over Vietnam and Operations Southern/Northern Watch. Over...of one PFT done on a weekly basis, although seemingly insignificant, could have enormous impact over time. Even the smallest regular cost savings...Force Flying Hour Costs Four variables make up the flying hour program. They are supplies (tools used to repair aircraft), impact card (purchases by

Dryden F-8 Research Aircraft Fleet 1973 in flight, DFBW and SCW

NASA Technical Reports Server (NTRS)

1973-01-01

F-8 Digital Fly-By-Wire (left) and F-8 Supercritical Wing in flight. These two aircraft fundamentally changed the nature of aircraft design. The F-8 DFBW pioneered digital flight controls and led to such computer-controlled airacrft as the F-117A, X-29, and X-31. Airliners such as the Boeing 777 and Airbus A320 also use digital fly-by-wire systems. The other aircraft is a highly modified F-8A fitted with a supercritical wing. Dr. Richard T. Whitcomb of Langley Research Center originated the supercritical wing concept in the late 1960s. (Dr. Whitcomb also developed the concept of the 'area rule' in the early 1950s. It singificantly reduced transonic drag.) The F-8 Digital Fly-By-Wire (DFBW) flight research project validated the principal concepts of all-electric flight control systems now used on nearly all modern high-performance aircraft and on military and civilian transports. The first flight of the 13-year project was on May 25, 1972, with research pilot Gary E. Krier at the controls of a modified F-8C Crusader that served as the testbed for the fly-by-wire technologies. The project was a joint effort between the NASA Flight Research Center, Edwards, California, (now the Dryden Flight Research Center) and Langley Research Center. It included a total of 211 flights. The last flight was December 16, 1985, with Dryden research pilot Ed Schneider at the controls. The F-8 DFBW system was the forerunner of current fly-by-wire systems used in the space shuttles and on today's military and civil aircraft to make them safer, more maneuverable, and more efficient. Electronic fly-by-wire systems replaced older hydraulic control systems, freeing designers to design aircraft with reduced in-flight stability. Fly-by-wire systems are safer because of their redundancies. They are more maneuverable because computers can command more frequent adjustments than a human pilot can. For airliners, computerized control ensures a smoother ride than a human pilot alone can provide

Large capacity oblique all-wing transport aircraft

NASA Technical Reports Server (NTRS)

Galloway, Thomas L.; Phillips, James A.; Kennelly, Robert A., Jr.; Waters, Mark H.

1996-01-01

Dr. R. T. Jones first developed the theory for oblique wing aircraft in 1952, and in subsequent years numerous analytical and experimental projects conducted at NASA Ames and elsewhere have established that the Jones' oblique wing theory is correct. Until the late 1980's all proposed oblique wing configurations were wing/body aircraft with the wing mounted on a pivot. With the emerging requirement for commercial transports with very large payloads, 450-800 passengers, Jones proposed a supersonic oblique flying wing in 1988. For such an aircraft all payload, fuel, and systems are carried within the wing, and the wing is designed with a variable sweep to maintain a fixed subsonic normal Mach number. Engines and vertical tails are mounted on pivots supported from the primary structure of the wing. The oblique flying wing transport has come to be known as the Oblique All-Wing (OAW) transport. This presentation gives the highlights of the OAW project that was to study the total concept of the OAW as a commercial transport.

Chemical hazards in aeromedical aircraft.

PubMed

Tupper, C R

1989-01-01

Several potentially hazardous chemicals are required to make modern military aircraft fly. With each airevac mission, the possibility exists for structural failure of a fluid system, resulting in contamination to flight/medical crews, patients, and passengers. Aeromedical Evacuation Crewmembers (AECMs) need to be aware of the hazardous chemicals used in aircraft and areas where there is an increased risk to those in and around the aircraft. This study identified potential areas for chemical leakage, such as refuel receptacles, hydraulic reservoirs, hydraulic motors, doors, ramps, engines, and more. Further, it identified the basic first aid procedures to perform on people contaminated with jet fuel, hydraulic fluid, engine oil, fire extinguisher agents, LOX and other fluids. First aid procedures are basic and can be performed with supplies and equipment on a routine aeromedical evacuation mission, AECMs trained in a basic awareness of hazardous aircraft chemicals will result in crews better prepared to cope with the unique risks of transporting patients in a complicated military aircraft.

Aircraft Configuration and Flight Crew Compliance with Procedures While Conducting Flight Deck Based Interval Management (FIM) Operations

NASA Technical Reports Server (NTRS)

Shay, Rick; Swieringa, Kurt A.; Baxley, Brian T.

2012-01-01

Flight deck based Interval Management (FIM) applications using ADS-B are being developed to improve both the safety and capacity of the National Airspace System (NAS). FIM is expected to improve the safety and efficiency of the NAS by giving pilots the technology and procedures to precisely achieve an interval behind the preceding aircraft by a specific point. Concurrently but independently, Optimized Profile Descents (OPD) are being developed to help reduce fuel consumption and noise, however, the range of speeds available when flying an OPD results in a decrease in the delivery precision of aircraft to the runway. This requires the addition of a spacing buffer between aircraft, reducing system throughput. FIM addresses this problem by providing pilots with speed guidance to achieve a precise interval behind another aircraft, even while flying optimized descents. The Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR) human-in-the-loop experiment employed 24 commercial pilots to explore the use of FIM equipment to conduct spacing operations behind two aircraft arriving to parallel runways, while flying an OPD during high-density operations. This paper describes the impact of variations in pilot operations; in particular configuring the aircraft, their compliance with FIM operating procedures, and their response to changes of the FIM speed. An example of the displayed FIM speeds used incorrectly by a pilot is also discussed. Finally, this paper examines the relationship between achieving airline operational goals for individual aircraft and the need for ATC to deliver aircraft to the runway with greater precision. The results show that aircraft can fly an OPD and conduct FIM operations to dependent parallel runways, enabling operational goals to be achieved efficiently while maintaining system throughput.

Using In Situ Eddy Covariance Flux Measurements from a Low Flying Aircraft in the Arctic to Measure Regional Methane Fluxes.

NASA Astrophysics Data System (ADS)

Sayres, D. S.; Dobosy, R.; Healy, C. E.; Dumas, E. J.; Kochendorfer, J.; Munster, J. B.; Wilkerson, J.; Baker, B.; Anderson, J. G.

2016-12-01

The Arctic terrestrial and subsea permafrost region contains approximately 30% of the global carbon stock and therefore understanding Arctic methane emissions and how they might change with a changing climate is important for quantifying the global methane budget and understanding its growth in the atmosphere. Here we present measurements from a new in situ flux observation system designed for use on a small, low-flying aircraft that flew over the North Slope of Alaska during August of 2013. The system combines a small methane instrument based on Integrated Cavity Output Spectroscopy (ICOS) with an air turbulence probe to calculate methane fluxes based on eddy covariance. Surface fluxes are grouped by ecotope using a map based on LandSat 30 meter resolution data. We find that wet sedge areas dominate the methane fluxes during the first part of August, with methane emissions from the Sagavanirktok river being the second highest. We compare the aircraft measurements with an eddy covariance flux tower located in a wet sedge area and show that the two measurements agree quantitatively when the footprints of both overlap. However, fluxes from sedge vary at times by a factor of two or more even within a few kilometers of the tower demonstrating the importance of making regional measurements to map out methane emission spatial heterogeneity. Aircraft measurements of surface flux can play an important role in bridging the gap between ground-based measurements and regional measurements from remote sensing instruments and models.

Formation flying benefits based on vortex lattice calculations

NASA Technical Reports Server (NTRS)

Maskew, B.

1977-01-01

A quadrilateral vortex-lattice method was applied to a formation of three wings to calculate force and moment data for use in estimating potential benefits of flying aircraft in formation on extended range missions, and of anticipating the control problems which may exist. The investigation led to two types of formation having virtually the same overall benefits for the formation as a whole, i.e., a V or echelon formation and a double row formation (with two staggered rows of aircraft). These formations have unequal savings on aircraft within the formation, but this allows large longitudinal spacings between aircraft which is preferable to the small spacing required in formations having equal benefits for all aircraft. A reasonable trade-off between a practical formation size and range benefit seems to lie at about three to five aircraft with corresponding maximum potential range increases of about 46 percent to 67 percent. At this time it is not known what fraction of this potential range increase is achievable in practice.

The Evolution of Instrument Flying in the U.S. Army.

DTIC Science & Technology

1988-04-01

had learned to fly in World War One without instruments. They either distrusted instruments and avoided clouds, or were "seat-of- the-pants" flyers...hooded flight training, Basic students received six hours, and Advanced students received fifteen. Primary and Basic students learned aircraft control and...instrument maneuvers while Advanced students learned radio-navigation.;’ The twenty-seven hours of instrument 23 flying represented 11 percent of the

Role of research aircraft in technology development

NASA Technical Reports Server (NTRS)

Szalai, K. J.

1984-01-01

The United States's aeronautical research program has been rich in the use of research aircraft to explore new flight regimes, develop individual aeronautical concepts, and investigate new vehicle classes and configurations. This paper reviews the NASA supercritical wing, digital fly-by-wire, HiMAT, and AD-1 oblique-wing flight research programs, and draws from these examples general conclusions regarding the role and impact of research aircraft in technology development. The impact of a flight program on spinoff technology is also addressed. The secondary, serendipitous results are often highly significant. Finally, future research aircraft programs are examined for technology trends and expected results.

Remotely piloted aircraft in the civil environment

NASA Technical Reports Server (NTRS)

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

1977-01-01

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.

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

NASA Technical Reports Server (NTRS)

1996-01-01

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.

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

NASA Technical Reports Server (NTRS)

1996-01-01

-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.

Space shuttle flying qualities and criteria assessment

NASA Technical Reports Server (NTRS)

Myers, T. T.; Johnston, D. E.; Mcruer, Duane T.

1987-01-01

Work accomplished under a series of study tasks for the Flying Qualities and Flight Control Systems Design Criteria Experiment (OFQ) of the Shuttle Orbiter Experiments Program (OEX) is summarized. The tasks involved review of applicability of existing flying quality and flight control system specification and criteria for the Shuttle; identification of potentially crucial flying quality deficiencies; dynamic modeling of the Shuttle Orbiter pilot/vehicle system in the terminal flight phases; devising a nonintrusive experimental program for extraction and identification of vehicle dynamics, pilot control strategy, and approach and landing performance metrics, and preparation of an OEX approach to produce a data archive and optimize use of the data to develop flying qualities for future space shuttle craft in general. Analytic modeling of the Orbiter's unconventional closed-loop dynamics in landing, modeling pilot control strategies, verification of vehicle dynamics and pilot control strategy from flight data, review of various existent or proposed aircraft flying quality parameters and criteria in comparison with the unique dynamic characteristics and control aspects of the Shuttle in landing; and finally a summary of conclusions and recommendations for developing flying quality criteria and design guides for future Shuttle craft.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing on Lakebed

NASA Technical Reports Server (NTRS)

1997-01-01

A quarter-scale model of the Centurion solar-powered flying wing rests on the clay of El Mirage Dry Lake in Southern California's high desert after completion of of a March 1997 flight test. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing on Lakebed

NASA Technical Reports Server (NTRS)

1997-01-01

A quarter-scale model of the Centurion solar-powered flying wing rests on the clay of El Mirage Dry Lake in Southern California's high desert after completion of a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft

The design of a joined wing flight demonstrator aircraft

NASA Technical Reports Server (NTRS)

Smith, S. C.; Cliff, S. E.; Kroo, I. M.

1987-01-01

A joined-wing flight demonstrator aircraft has been developed at the NASA Ames Research Center in collaboration with ACA Industries. The aircraft is designed to utilize the fuselage, engines, and undercarriage of the existing NASA AD-1 flight demonstrator aircraft. The design objectives, methods, constraints, and the resulting aircraft design, called the JW-1, are presented. A wind-tunnel model of the JW-1 was tested in the NASA Ames 12-foot wind tunnel. The test results indicate that the JW-1 has satisfactory flying qualities for a flight demonstrator aircraft. Good agreement of test results with design predictions confirmed the validity of the design methods used for application to joined-wing configurations.

Applications of advanced electric/electronic technology to conventional aircraft

NASA Technical Reports Server (NTRS)

Heimbold, R. L.

1980-01-01

The desirability of seven advanced technologies as applied to three commercial aircraft of 1985 to 1995 was investigated. Digital fly by wire, multiplexing, ring laser gyro, integrated avionics, all electric airplane, electric load management, and fiber optics were considered for 500 passenger, 50 passenger, and 30 passenger aircraft. The major figure of merit used was Net Value of Technology based on procurement and operating cost over the life of the aircraft. An existing computer program, ASSET, was used to resize the aircraft and evalute fuel usage and maintenance costs for each candidate configuration. Conclusions were that, for the 500 passenger aircraft, all candidates had a worthwhile payoff with the all electric airplane having a large payoff.

Evaluation of Flying Qualities and Guidance Displays for an Advanced Tilt-Wing STOL Transport Aircraft in Final Approach and Landing

NASA Technical Reports Server (NTRS)

Frost, Chad R.; Franklin, James A.; Hardy, Gordon H.

2002-01-01

A piloted simulation was performed on the Vertical Motion Simulator at NASA Ames Research Center to evaluate flying qualities of a tilt-wing Short Take-Off and Landing (STOL) transport aircraft during final approach and landing. The experiment was conducted to assess the design s handling qualities, and to evaluate the use of flightpath-centered guidance for the precision approach and landing tasks required to perform STOL operations in instrument meteorological conditions, turbulence, and wind. Pilots rated the handling qualities to be satisfactory for all operations evaluated except those encountering extreme crosswinds and severe windshear; even in these difficult meteorological conditions, adequate handling qualities were maintained. The advanced flight control laws and guidance displays provided consistent performance and precision landings.

Flying Cars

NASA Technical Reports Server (NTRS)

Crow, Steven

1996-01-01

Flying cars have nearly mythical appeal to nonpilots, a group that includes almost the whole human race. The appeal resides in the perceived utility of flying cars, vehicles that offer portal-to-portal transportation, yet break the bonds of road and traffic and travel freely through the sky at the drivers will. Part of the appeal is an assumption that flying cars can be as easy to fly as to drive. Flying cars have been part of the dream of aviation since the dawn of powered flight. Glenn Curtiss built, displayed, and maybe even flew a flying car in 1917, the Curtiss Autoplane. Many roadable airplanes were built in the 1930's, like the Waterman Arrowbile and the Fulton Airphibian. Two flying cars came close to production in the early 1950's. Ted Hall built a series of flying cars culminating in the Convaircar, sponsored by Consolidated Vultee, General Motors, and Hertz. Molt Taylor built and certified his Aerocar, and Ford came close to producing them. Three Aerocars are still flyable, two in museums in Seattle and Oshkosh, and the third owned and flown by Ed Sweeny. Flying cars do have problems, which so far have prevented commercial success. An obvious problem is complexity of the vehicle, the infrastructure, or both. Another is the difficulty of matching low power for normal driving with high power in flight. An automobile uses only about 20 hp at traffic speeds, while a personal airplane needs about 160 hp at speeds typical of flight. Many automobile engines can deliver 160 hp, but not for very long. A more subtle issue involves the drag of automobiles and airplanes. A good personal airplane can fly 30 miles per gallon of fuel at 200 mph. A good sports car would need 660 hp at the same speed and would travel only 3 miles per gallon. The difference is drag area, about 4.5 sq ft for the automobile and 1.4 sq ft for the airplane. A flying car better have the drag area of the airplane, not the car!

Automated optimization techniques for aircraft synthesis

NASA Technical Reports Server (NTRS)

Vanderplaats, G. N.

1976-01-01

Application of numerical optimization techniques to automated conceptual aircraft design is examined. These methods are shown to be a general and efficient way to obtain quantitative information for evaluating alternative new vehicle projects. Fully automated design is compared with traditional point design methods and time and resource requirements for automated design are given. The NASA Ames Research Center aircraft synthesis program (ACSYNT) is described with special attention to calculation of the weight of a vehicle to fly a specified mission. The ACSYNT procedures for automatically obtaining sensitivity of the design (aircraft weight, performance and cost) to various vehicle, mission, and material technology parameters are presented. Examples are used to demonstrate the efficient application of these techniques.

Human-centered aircraft automation: A concept and guidelines

NASA Technical Reports Server (NTRS)

Billings, Charles E.

1991-01-01

Aircraft automation is examined and its effects on flight crews. Generic guidelines are proposed for the design and use of automation in transport aircraft, in the hope of stimulating increased and more effective dialogue among designers of automated cockpits, purchasers of automated aircraft, and the pilots who must fly those aircraft in line operations. The goal is to explore the means whereby automation may be a maximally effective tool or resource for pilots without compromising human authority and with an increase in system safety. After definition of the domain of the aircraft pilot and brief discussion of the history of aircraft automation, a concept of human centered automation is presented and discussed. Automated devices are categorized as a control automation, information automation, and management automation. The environment and context of aircraft automation are then considered, followed by thoughts on the likely future of automation of that category.

Pilot Ed Lewis with T-34C aircraft on ramp

NASA Image and Video Library

1998-03-04

NASA pilot Ed Lewis with the T-34C aircraft on the Dryden Flight Research Center Ramp. The aircraft was previously used at the Lewis Research Center in propulsion experiments involving turboprop engines, and was used as a chase aircraft at Dryden for smaller and slower research projects. Chase aircraft accompany research flights for photography and video purposes, and also as support for safety and research. At Dryden, the T-34 is used mainly for smaller remotely piloted vehicles which fly slower than NASA's F-18's, used for larger scale projects. This aircraft was returned to the U.S. Navy in May of 2002.

Aircraft Mechanics Series. Duty Task List.

ERIC Educational Resources Information Center

Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

This task list is intended for use in planning and/or evaluating a competency-based course in aircraft mechanics. The guide outlines the tasks entailed in 24 different duties typically required of employees in the following occupations: airframe mechanic, power plant mechanic, aircraft mechanic, aircraft sheet metal worker, aircraft electrician,…

Design of a spanloader cargo aircraft

NASA Technical Reports Server (NTRS)

1989-01-01

With a growing demand for fast international freight service, the slow-moving cargo ships currently in use will soon find a substantial portion of their clients looking elsewhere. One candidate for filling this expected gap in the freight market is a span-loading aircraft (or 'flying wing') capable of long-range operation with extremely large payloads. This report summarizes the design features of an aircraft capable of fulfilling a long-haul, high-capacity cargo mission. The spanloader seeks to gain advantage over conventional aircraft by eliminating the aircraft fuselage and thus reducing empty weight. The primary disadvantage of this configuration is that the cargo-containing wing tends to be thick, thus posing a challenge to the airfoil designer. It also suffers from stability and control problems not encountered by conventional aircraft. The result is an interesting, challenging exercise in unconventional design. The report that follows is a student written synopsis of an effort judged to be the best of eight designs developed during the year 1988-1989.

Oblique Wing Research Aircraft on ramp

NASA Technical Reports Server (NTRS)

1976-01-01

This 1976 photograph of the Oblique Wing Research Aircraft was taken in front of the NASA Flight Research Center hangar, located at Edwards Air Force Base, California. In the photograph the noseboom, pitot-static probe, and angles-of-attack and sideslip flow vanes(covered-up) are attached to the front of the vehicle. The clear nose dome for the television camera, and the shrouded propellor for the 90 horsepower engine are clearly seen. The Oblique Wing Research Aircraft was a small, remotely piloted, research craft designed and flight tested to look at the aerodynamic characteristics of an oblique wing and the control laws necessary to achieve acceptable handling qualities. NASA Dryden Flight Research Center and the NASA Ames Research Center conducted research with this aircraft in the mid-1970s to investigate the feasibility of flying an oblique wing aircraft.

High-speed Civil Transport Aircraft Emissions

NASA Technical Reports Server (NTRS)

Miake-Lye, Richard C.; Matulaitis, J. A.; Krause, F. H.; Dodds, Willard J.; Albers, Martin; Hourmouziadis, J.; Hasel, K. L.; Lohmann, R. P.; Stander, C.; Gerstle, John H.

1992-01-01

Estimates are given for the emissions from a proposed high speed civil transport (HSCT). This advanced technology supersonic aircraft would fly in the lower stratosphere at a speed of roughly Mach 1.6 to 3.2 (470 to 950 m/sec or 920 to 1850 knots). Because it would fly in the stratosphere at an altitude in the range of 15 to 23 km commensurate with its design speed, its exhaust effluents could perturb the chemical balance in the upper atmosphere. The first step in determining the nature and magnitude of any chemical changes in the atmosphere resulting from these proposed aircraft is to identify and quantify the chemically important species they emit. Relevant earlier work is summarized, dating back to the Climatic Impact Assessment Program of the early 1970s and current propulsion research efforts. Estimates are provided of the chemical composition of an HSCT's exhaust, and these emission indices are presented. Other aircraft emissions that are not due to combustion processes are also summarized; these emissions are found to be much smaller than the exhaust emissions. Future advances in propulsion technology, in experimental measurement techniques, and in understanding upper atmospheric chemistry may affect these estimates of the amounts of trace exhaust species or their relative importance.

Technologies for Aircraft Noise Reduction

NASA Technical Reports Server (NTRS)

Huff, Dennis L.

2006-01-01

Technologies for aircraft noise reduction have been developed by NASA over the past 15 years through the Advanced Subsonic Technology (AST) Noise Reduction Program and the Quiet Aircraft Technology (QAT) project. This presentation summarizes highlights from these programs and anticipated noise reduction benefits for communities surrounding airports. Historical progress in noise reduction and technologies available for future aircraft/engine development are identified. Technologies address aircraft/engine components including fans, exhaust nozzles, landing gear, and flap systems. New "chevron" nozzles have been developed and implemented on several aircraft in production today that provide significant jet noise reduction. New engines using Ultra-High Bypass (UHB) ratios are projected to provide about 10 EPNdB (Effective Perceived Noise Level in decibels) engine noise reduction relative to the average fleet that was flying in 1997. Audio files are embedded in the presentation that estimate the sound levels for a 35,000 pound thrust engine for takeoff and approach power conditions. The predictions are based on actual model scale data that was obtained by NASA. Finally, conceptual pictures are shown that look toward future aircraft/propulsion systems that might be used to obtain further noise reduction.

Progress in aircraft design since 1903

NASA Technical Reports Server (NTRS)

1974-01-01

Significant developments in aviation history are documented to show the advancements in aircraft design which have taken place since 1903. Each aircraft is identified according to the manufacturer, powerplant, dimensions, normal weight, and typical performance. A narrative summary of the major accomplishments of the aircraft is provided. Photographs of each aircraft are included.

Advanced control technology and its potential for future transport aircraft

NASA Technical Reports Server (NTRS)

1976-01-01

The topics covered include fly by wire, digital control, control configured vehicles, applications to advanced flight vehicles, advanced propulsion control systems, and active control technology for transport aircraft.

Interaction of feel system and flight control system dynamics on lateral flying qualities

NASA Technical Reports Server (NTRS)

Bailey, R. E.; Knotts, L. H.

1990-01-01

An experimental investigation of the influence of lateral feel system characteristics on fighter aircraft roll flying qualities was conducted using the variable stability USAF NT-33. Forty-two evaluation flights were flown by three engineering test pilots. The investigation utilized the power approach, visual landing task and up-and-away tasks including formation, gun tracking, and computer-generated compensatory attitude tracking tasks displayed on the Head-Up Display. Experimental variations included the feel system frequency, force-deflection gradient, control system command type (force or position input command), aircraft roll mode time constant, control system prefilter frequency, and control system time delay. The primary data were task performance records and evaluation pilot comments and ratings using the Cooper-Harper scale. The data highlight the unique and powerful effect of the feel system of flying qualities. The data show that the feel system is not 'equivalent' in flying qualities influence to analogous control system elements. A lower limit of allowable feel system frequency appears warranted to ensure good lateral flying qualities. Flying qualities criteria should most properly treat the feel system dynamic influence separately from the control system, since the input and output of this dynamic element is apparent to the pilot and thus, does not produce a 'hidden' effect.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Silhouetted under a bright blue sky, a quarter-scale model of the Centurion solar-powered flying wing shows off its long, narrow wing as it flies over the broad expanse of El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del

Methane eddy covariance flux measurements from a low flying aircraft: Bridging the scale gap between local and regional emissions estimates

NASA Astrophysics Data System (ADS)

Sayres, D. S.; Dobosy, R.; Dumas, E. J.; Kochendorfer, J.; Wilkerson, J.; Anderson, J. G.

2017-12-01

The Arctic contains a large reservoir of organic matter stored in permafrost and clathrates. Varying geology and hydrology across the Arctic, even on small scales, can cause large variability in surface carbon fluxes and partitioning between methane and carbon dioxide. This makes upscaling from point source measurements such as small flux towers or chambers difficult. Ground based measurements can yield high temporal resolution and detailed information about a specific location, but due to the inaccessibility of most of the Arctic to date have only made measurements at very few sites. In August 2013, a small aircraft, flying low over the surface (5-30 m), and carrying an air turbulence probe and spectroscopic instruments to measure methane, carbon dioxide, nitrous oxide, water vapor and their isotopologues, flew over the North Slope of Alaska. During the six flights multiple comparisons were made with a ground based Eddy Covariance tower as well as three region surveys flights of fluxes over three areas each approximately 2500 km2. We present analysis using the Flux Fragment Method and surface landscape classification maps to relate the fluxes to different surface land types. We show examples of how we use the aircraft data to upscale from a eddy covariance tower and map spatial variability across different ecotopes.

Meet your Aircraft Quiz

DOT National Transportation Integrated Search

1995-01-01

This quiz is designed to help a pilot meet his or her aircraft. Although no attempt is made to cover in depth all of the information contained in the typical Pilot's Operating Handbook (POH), Owner's Manual (OM), or Aircraft Flight Manual (AFM), the ...

Evaluating and minimizing noise impact due to aircraft flyover

NASA Technical Reports Server (NTRS)

Jacobson, I. D.

1980-01-01

The results of a study on the evaluation and reduction of noise impact to a community due to aircraft landing and takeoff operations are presented. The case of multiple aircrafts flying on several trajectories, for either approach/landings or takeoffs was examined. An extremely realistic model of the flight path was developed. The annoyance criterion used was the noise impact index (NII). The algorithm was applied to Patrick Henry International Airport.

Pilot Preferences on Displayed Aircraft Control Variables

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.; Gregory, Irene M.

2013-01-01

The experiments described here explored how pilots want available maneuver authority information transmitted and how this information affects pilots before and after an aircraft failure. The aircraft dynamic variables relative to flight performance were narrowed to energy management variables. A survey was conducted to determine what these variables should be. Survey results indicated that bank angle, vertical velocity, and airspeed were the preferred variables. Based on this, two displays were designed to inform the pilot of available maneuver envelope expressed as bank angle, vertical velocity, and airspeed. These displays were used in an experiment involving control surface failures. Results indicate the displayed limitations in bank angle, vertical velocity, and airspeed were helpful to the pilots during aircraft surface failures. However, the additional information did lead to a slight increase in workload, a small decrease in perceived aircraft flying qualities, and no effect on aircraft situation awareness.

Roles, uses, and benefits of general aviation aircraft in aerospace engineering education

NASA Technical Reports Server (NTRS)

Odonoghue, Dennis P.; Mcknight, Robert C.

1994-01-01

Many colleges and universities throughout the United States offer outstanding programs in aerospace engineering. In addition to the fundamentals of aerodynamics, propulsion, flight dynamics, and air vehicle design, many of the best programs have in the past provided students the opportunity to design and fly airborne experiments on board various types of aircraft. Sadly, however, the number of institutions offering such 'airborne laboratories' has dwindled in recent years. As a result, opportunities for students to apply their classroom knowledge, analytical skills, and engineering judgement to the development and management of flight experiments on an actual aircraft are indeed rare. One major reason for the elimination of flight programs by some institutions, particularly the smaller colleges, is the prohibitive cost of operating and maintaining an aircraft as a flying laboratory. The purpose of this paper is to discuss simple, low-cost, relevant flight experiments that can be performed using readily available general aviation aircraft. This paper examines flight experiments that have been successfully conducted on board the NASA Lewis Research Center's T-34B aircraft, as part of the NASA/AIAA/University Flight Experiment Program for Students (NAUFEPS) and discusses how similar experiments could be inexpensively performed on other general aviation aircraft.

Flared landing approach flying qualities. Volume 2: Appendices

NASA Technical Reports Server (NTRS)

Weingarten, Norman C.; Berthe, Charles J., Jr.; Rynaski, Edmund G.; Sarrafian, Shahan K.

1986-01-01

An in-flight research study was conducted utilizing the USAF/Total In-Flight Simulator (TIFS) to investigate longitudinal flying qualities for the flared landing approach phase of flight. A consistent set of data were generated for: determining what kind of command response the pilot prefers/requires in order to flare and land an aircraft with precision, and refining a time history criterion that took into account all the necessary variables and the characteristics that would accurately predict flying qualities. Seven evaluation pilots participated representing NASA Langley, NASA Dryden, Calspan, Boeing, Lockheed, and DFVLR (Braunschweig, Germany). The results of the first part of the study provide guidelines to the flight control system designer, using MIL-F-8785-(C) as a guide, that yield the dynamic behavior pilots prefer in flared landings. The results of the second part provide the flying qualities engineer with a derived flying qualities predictive tool which appears to be highly accurate. This time-domain predictive flying qualities criterion was applied to the flight data as well as six previous flying qualities studies, and the results indicate that the criterion predicted the flying qualities level 81% of the time and the Cooper-Harper pilot rating, within + or - 1%, 60% of the time.

Response of geese to aircraft disturbances

USGS Publications Warehouse

Ward, David; Stehn, Robert A.; Derksen, Dirk V.

2000-01-01

Low-flying aircraft can affect behavior, physiology, and distribution of wildlife (Manci et al., 1988), and over time, may impact a population by reducing survival and reproductive performance. Thus, it is important to identify the particular aspects of overflights that affect animals so that management strategies can be developed to minimize adverse effects.Waterfowl are particularly sensitive to low-flying aircraft (Manci et al., 1988) and respond at all stages of their annual cycle, including breeding (Gollop et al., 1974a; Laing, 1991), molting (Derksen et al., 1979; Mosbech and Glahder, 1991), migration (Jones and Jones, 1966; Belanger and Bedard, 1989), and wintering (Owens, 1977; Kramer et al., 1979; Henry, 1980). Waterfowl response can be quite variable both within and among species (Fleming et al., 1996). For example, response can vary with age, sex, and body condition of individual, habitat type and quality, and previous exposure to aircraft (Dahlgren and Korshgen, 1992). However, the most important factors influencing a response are aircraft type (Davis and Wiseley, 1974; Jensen, 1990), noise (Mosbech and Glahder, 1991; Temple, 1993), and proximity to the birds, as measured in altitude and lateral distance (Derksen et al., 1979; Belanger and Bedard, 1989; Ward et al., 1994). Wildlife managers can reduce impacts on a population by controlling or modifying these factors.In an experimental study conducted at Izembek Lagoon in southwestern Alaska in 1985-1988 (Ward and Stehn, 1989), we conducted planned aircraft overflights with control of aircraft type, noise, altitude, and lateral distance to flocks (hereafter called lateral distance) to measure behavioral response of fall-staging Pacific brant (Branta bernicla nigricans) and Canada geese (B. canadensis taverneri) to fixed- and rotary-wing aircraft. These data were then used to develop predictive models of the relationship between aircraft type, noise, altitude, and lateral distance and the response of

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Illuminated by early-morning sunlight, a quarter-scale model of the Solar-powered, remotely piloted Centurion ultra-high-altitude flying wing demonstrates its abilities during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Illuminated by early-morning sunlight, a quarter-scale model of the solar-powered, remotely piloted Centurion ultra-high-altitude flying wing soars over California's Mojave Desert on a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for

Recommendations for field measurements of aircraft noise

NASA Technical Reports Server (NTRS)

Marsh, A. H.

1982-01-01

Specific recommendations for environmental test criteria, data acquisition procedures, and instrument performance requirements for measurement of noise levels produced by aircraft in flight are provided. Recommendations are also given for measurement of associated airplane and engine parameters and atmospheric conditions. Recommendations are based on capabilities which were available commercially in 1981; they are applicable to field tests of aircraft flying subsonically past microphones located near the surface of the ground either directly under or to the side of a flight path. Aircraft types covered by the recommendations include fixed-wing airplanes powered by turbojet or turbofan engines or by propellers. The recommended field-measurement procedures are consistent with assumed requirements for data processing and analysis.

USAF Test Pilot School. Flying Qualities Textbook, Volume 2, Part 1

DTIC Science & Technology

1986-04-01

Qualities Flight Testing, Performance and Flying Qaulities Branch, Flight Test Engneerd ision, 6510th Test Wing, Air Force Flight Mayst Ce1ter, Edwards...For these aircraft, the program manager may re*uire a mil spec written specifically for the aircraft and control system involwd. 5.20.2 _EL k,Tt...OR MANAGED IN CONTEXT OF MISSION, WITH AVAILABLE PILOT ATTENTION. S UNCONTROLLABLE CONTROL WILL BE LOST DURING SOME PORTION OF MISSION. ACCEPTABLE

Propulsion system study for Small Transport Aircraft Technology (STAT)

NASA Technical Reports Server (NTRS)

Smith, C. E.; Hirschkron, R.; Warren, R. E.

1981-01-01

Propulsion system technologies applicable to the generation of commuter airline aircraft expected to enter service in the 1990's are identified and evaluated in terms of their impact on aircraft operating economics and fuel consumption. The most promising technologies in the areas of engine, propeller, gearbox, and nacelle design are recommended for future research. Each item under consideration is evaluated relative to a modern baseline engine, the General Electric CT7-5, in a current technology aircraft flying a fixed range and payload. The analysis is presented for two aircraft sizes (30 and 50 passenger), over a range of mission lengths (100 to 1100 km) and fuel costs ($264 to $396 per cu m).

A new direction in energy conversion - The all-electric aircraft

NASA Technical Reports Server (NTRS)

Spitzer, C. R.

1985-01-01

This paper reviews recent studies of all-electric aircraft that use electric-only secondary power and flight critical fly-by-wire flight controls, and brings to the attention of the power system designer the intrinsic advantages of such aircraft. The all-electric aircraft is made possible by the development of rare earth magnet materials and fault tolerant systems technologies. Recent studies have shown all-electric aircraft to be more efficient than conventional designs and offer substantial operating costs reductions. Compared to present aircraft, an all-electric transport can save at least 10 percent in fuel burn. The cornerstone of an all-electric aircraft is the electric secondary power system. This paper reviews the major features of flight critical electric secondary power systems. Research required to lay the foundation for an all-electric aircraft is briefly discussed.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing Landing during First

NASA Technical Reports Server (NTRS)

1997-01-01

A quarter-scale model of the future Centurion solar-powered high-altitude research aircraft settles in for landing after a March 1997 test flight at El Mirage Dry Lake, California. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he

V/STOL Dynamics, Control, and Flying Qualities

NASA Technical Reports Server (NTRS)

Franklin, James A.

2000-01-01

This publication presents material that constituted the lectures presented by the author as part of Course AA 234, Dynamics, Control, and Flying Qualities of Vertical/Short Takeoff and Landing (V/STOL) Aircraft that was taught in the Department of Aeronautics and Astronautics at Stanford University. It covers representative operations of vertical and short takeoff and landing (V/STOL) aircraft, a discussion of the pilot's strategy in controlling these aircraft, the equations of motion pertinent to V/STOL tasks, and their application in the analysis of longitudinal and lateral-directional control in hover and forward flight. Following that development, which applies to the characteristics of the basic airframe and propulsion system, the text concludes with a discussion of the contributions of control augmentation in specific flight tasks and of the integration of modern electronic displays with these controls.

Prediction of the Electromagnetic Field Distribution in a Typical Aircraft Using the Statistical Energy Analysis

NASA Astrophysics Data System (ADS)

Kovalevsky, Louis; Langley, Robin S.; Caro, Stephane

2016-05-01

Due to the high cost of experimental EMI measurements significant attention has been focused on numerical simulation. Classical methods such as Method of Moment or Finite Difference Time Domain are not well suited for this type of problem, as they require a fine discretisation of space and failed to take into account uncertainties. In this paper, the authors show that the Statistical Energy Analysis is well suited for this type of application. The SEA is a statistical approach employed to solve high frequency problems of electromagnetically reverberant cavities at a reduced computational cost. The key aspects of this approach are (i) to consider an ensemble of system that share the same gross parameter, and (ii) to avoid solving Maxwell's equations inside the cavity, using the power balance principle. The output is an estimate of the field magnitude distribution in each cavity. The method is applied on a typical aircraft structure.

Techno-economic requirements for composite aircraft components

NASA Technical Reports Server (NTRS)

Palmer, Ray

1993-01-01

The primary reason for use of composites is to save structural weight. A well designed composite aircraft structure will usually save 25-30 percent of a well designed metal structure. The weight savings then translates into improved performance of the aircraft in measures of greater payload, increased flying range or improved efficiency - less use of fuel. Composite materials offer technical advantages. Key technical advantages that composites offer are high stiffness, tailored strength capability, fatigue resistance, and corrosion resistance. Low thermal expansion properties produce dimensionally stable structures over a wide range of temperature. Specialty resin 'char' forming characteristics in a fire environment offer potential fire barrier application and safer aircraft. The materials and processes of composite fabrication offer the potential for lower cost structures in the near future. The application of composite materials to aircraft are discussed.

Fly-by-light technology development plan

NASA Technical Reports Server (NTRS)

Todd, J. R.; Williams, T.; Goldthorpe, S.; Hay, J.; Brennan, M.; Sherman, B.; Chen, J.; Yount, Larry J.; Hess, Richard F.; Kravetz, J.

1990-01-01

The driving factors and developments which make a fly-by-light (FBL) viable are discussed. Documentation, analyses, and recommendations are provided on the major issues pertinent to facilitating the U.S. implementation of commercial FBL aircraft before the turn of the century. Areas of particular concern include ultra-reliable computing (hardware/software); electromagnetic environment (EME); verification and validation; optical techniques; life-cycle maintenance; and basis and procedures for certification.

Intelligent Control Approaches for Aircraft Applications

NASA Technical Reports Server (NTRS)

Gundy-Burlet, Karen; KrishnaKumar, K.; Soloway, Don; Kaneshige, John; Clancy, Daniel (Technical Monitor)

2001-01-01

This paper presents an overview of various intelligent control technologies currently being developed and studied under the Intelligent Flight Control (IFC) program at the NASA Ames Research Center. The main objective of the intelligent flight control program is to develop the next generation of flight controllers for the purpose of automatically compensating for a broad spectrum of damaged or malfunctioning aircraft components and to reduce control law development cost and time. The approaches being examined include: (a) direct adaptive dynamic inverse controller and (b) an adaptive critic-based dynamic inverse controller. These approaches can utilize, but do not require, fault detection and isolation information. Piloted simulation studies are performed to examine if the intelligent flight control techniques adequately: 1) Match flying qualities of modern fly-by-wire flight controllers under nominal conditions; 2) Improve performance under failure conditions when sufficient control authority is available; and 3) Achieve consistent handling qualities across the flight envelope and for different aircraft configurations. Results obtained so far demonstrate the potential for improving handling qualities and significantly increasing survivability rates under various simulated failure conditions.

Description and Flight Test Results of the NASA F-8 Digital Fly-by-Wire Control System

NASA Technical Reports Server (NTRS)

1975-01-01

A NASA program to develop digital fly-by-wire (DFBW) technology for aircraft applications is discussed. Phase I of the program demonstrated the feasibility of using a digital fly-by-wire system for aircraft control through developing and flight testing a single channel system, which used Apollo hardware, in an F-8C airplane. The objective of Phase II of the program is to establish a technology base for designing practical DFBW systems. It will involve developing and flight testing a triplex digital fly-by-wire system using state-of-the-art airborne computers, system hardware, software, and redundancy concepts. The papers included in this report describe the Phase I system and its development and present results from the flight program. Man-rated flight software and the effects of lightning on digital flight control systems are also discussed.

The Electrocardiogram and Ischemic Heart Disease in Aircraft Pilots

PubMed Central

Manning, G. W.

1965-01-01

A review of the Royal Canadian Air Force electrocardiographic (ECG) program for selection of aircrew and detection of coronary disease in trained aircrew is presented. Twenty reported cases of death due to coronary disease in pilots while at the controls of an aircraft are reviewed. The use of routine electrocardiography in the selection of aircrew has proved to be of considerable value, particularly in view of the high cost of training. The ECG continues to be our most sensitive means of detecting asymptomatic coronary disease in aircrew personnel. It is apparent that from both the military and commercial standpoint the incidence of aircraft accidents due to coronary disease is extremely small. This is due in large part to the careful medical supervision of flying personnel including the routine use of electrocardiography in the assessment of flying fitness of aircrew. PMID:14323657

Aircraft loss-of-control prevention and recovery: A hybrid control strategy

NASA Astrophysics Data System (ADS)

Dongmo, Jean-Etienne Temgoua

The Complexity of modern commercial and military aircrafts has necessitated better protection and recovery systems. With the tremendous advances in computer technology, control theory and better mathematical models, a number of issues (Prevention, Reconfiguration, Recovery, Operation near critical points, ... etc) moderately addressed in the past have regained interest in the aeronautical industry. Flight envelope is essential in all flying aerospace vehicles. Typically, flying the vehicle means remaining within the flight envelope at all times. Operation outside the normal flight regime is usually subject to failure of components (Actuators, Engines, Deflection Surfaces) , pilots's mistakes, maneuverability near critical points and environmental conditions (crosswinds...) and in general characterized as Loss-Of-Control (LOC) because the aircraft no longer responds to pilot's inputs as expected. For the purpose of this work, (LOC) in aircraft is defined as the departure from the safe set (controlled flight) recognized as the maximum controllable (reachable) set in the initial flight envelope. The LOC can be reached either through failure, unintended maneuvers, evolution near irregular points and disturbances. A coordinated strategy is investigated and designed to ensure that the aircraft can maneuver safely in their constraint domain and can also recover from abnormal regime. The procedure involves the computation of the largest controllable (reachable) set (Safe set) contained in the initial prescribed envelope. The problem is posed as a reachability problem using Hamilton-Jacobi Partial Differential Equation (HJ-PDE) where a cost function is set to he minimized along trajectory departing from the given set. Prevention is then obtained by computing the controller which would allow the flight vehicle to remain in the maximum controlled set in a multi-objective set up. Then the recovery procedure is illustrated with a two-point boundary value problem. Once

Venus Atmospheric Exploration by Solar Aircraft

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; LaMarre, C.; Colozza, A.

2002-01-01

The Venus atmosphere is a favorable environment for flying powered aircraft. The atmospheric pressure makes flight much easier than on planets such as Mars. Above the clouds, solar energy is available in abundance on Venus, and the slow rotation of Venus allows a solar airplane to be designed for flight within continuous sunlight. The atmosphere between 50 km and 75 km on Venus is one of the most dynamic and interesting regions of the planet. The challenge for a Venus aircraft will be the fierce winds and caustic atmosphere. In order to remain on the sunlit side of Venus, an exploration aircraft will have to be capable of sustained flight at or above the wind speed. An aircraft would be a powerful tool for exploration. By learning how Venus can be so similar to Earth, and yet so different, we will learn to better understand the climate and geological history of the Earth.

Hovering of a jellyfish-like flying machine

NASA Astrophysics Data System (ADS)

Ristroph, Leif; Childress, Stephen

2013-11-01

Ornithopters, or flapping-wing aircraft, offer an alternative to helicopters in achieving maneuverability at small scales, although stabilizing such aerial vehicles remains a key challenge. Here, we present a hovering machine that achieves self-righting flight using flapping wings alone, without relying on additional aerodynamic surfaces and without feedback control. We design, construct, and test-fly a prototype that opens and closes four wings, resembling the motions of swimming jellyfish more so than any insect or bird. Lift measurements and high-speed video of free-flight are used to inform an aerodynamic model that explains the stabilization mechanism. These results show the promise of flapping-flight strategies beyond those that directly mimic the wing motions of flying animals.

The retention of manual flying skills in the automated cockpit.

PubMed

Casner, Stephen M; Geven, Richard W; Recker, Matthias P; Schooler, Jonathan W

2014-12-01

The aim of this study was to understand how the prolonged use of cockpit automation is affecting pilots' manual flying skills. There is an ongoing concern about a potential deterioration of manual flying skills among pilots who assume a supervisory role while cockpit automation systems carry out tasks that were once performed by human pilots. We asked 16 airline pilots to fly routine and nonroutine flight scenarios in a Boeing 747-400 simulator while we systematically varied the level of automation that they used, graded their performance, and probed them about what they were thinking about as they flew. We found pilots' instrument scanning and manual control skills to be mostly intact, even when pilots reported that they were infrequently practiced. However, when pilots were asked to manually perform the cognitive tasks needed for manual flight (e.g., tracking the aircraft's position without the use of a map display, deciding which navigational steps come next, recognizing instrument system failures), we observed more frequent and significant problems. Furthermore, performance on these cognitive tasks was associated with measures of how often pilots engaged in task-unrelated thought when cockpit automation was used. We found that while pilots' instrument scanning and aircraft control skills are reasonably well retained when automation is used, the retention of cognitive skills needed for manual flying may depend on the degree to which pilots remain actively engaged in supervising the automation.

Shuttle Discovery Fly-Over

NASA Image and Video Library

2012-04-17

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) flies over the Steven F. Udvar-Hazy Center, Tuesday, April 17, 2012, in Washington. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Smithsonian Institution/Dane Penland)

Interpreting the handling qualities of aircraft with stability and control augmentation

NASA Technical Reports Server (NTRS)

Hodgkinson, J.; Potsdam, E. H.; Smith, R. E.

1990-01-01

The general process of designing an aircraft for good flying qualities is first discussed. Lessons learned are pointed out, with piloted evaluation emerging as a crucial element. Two sources of rating variability in performing these evaluations are then discussed. First, the finite endpoints of the Cooper-Harper scale do not bias parametric statistical analyses unduly. Second, the wording of the scale does introduce some scatter. Phase lags generated by augmentation systems, as represented by equivalent time delays, often cause poor flying qualities. An analysis is introduced which allows a designer to relate any level of time delay to a probability of loss of aircraft control. This view of time delays should, it is hoped, allow better visibility of the time delays in the design process.

Experimental investigation of lift enhancement for flying wing aircraft using nanosecond DBD plasma actuators

NASA Astrophysics Data System (ADS)

Yao, Junkai; Zhou, Danjie; He, Haibo; He, Chengjun; Shi, Zhiwei; Du, Hai

2017-04-01

The effects of the arrangement position and control parameters of nanosecond dielectric barrier discharge (NS-DBD) plasma actuators on lift enhancement for flying wing aircraft were investigated through wind tunnel experiments at a flow speed of 25 m s-1. The aerodynamic forces and moments were obtained by a six-component balance at angles of attack ranging from -4° to 28°. The lift, drag and pitching moment coefficients were compared for the cases with and without plasma control. The results revealed that the maximum control effect was achieved by placing the actuator at the leading edge of the inner and middle wing, for which the maximum lift coefficient increased by 37.8% and the stall angle of attack was postponed by 8° compared with the plasma-off case. The effects of modulation frequency and discharge voltage were also investigated. The results revealed that the lift enhancement effect of the NS-DBD plasma actuators was strongly influenced by the modulation frequency. Significant control effects were obtained at f = 70 Hz, corresponding to F + ≈ 1. The result for the pitching moment coefficient demonstrated that the plasma actuator can induce the reattachment of the separation flows when it is actuated. However, the results indicated that the discharge voltage had a negligible influence on the lift enhancement effect.

In-flight detection and identification and accommodation of aircraft icing

NASA Astrophysics Data System (ADS)

Caliskan, Fikret; Hajiyev, Chingiz

2012-11-01

The recent improvements and research on aviation have focused on the subject of aircraft safe flight even in the severe weather conditions. As one type of such weather conditions, aircraft icing considerably has negative effects on the aircraft flight performance. The risks of the iced aerodynamic surfaces of the flying aircraft have been known since the beginning of the first flights. Until recent years, as a solution for this event, the icing conditions ahead flight route are estimated from radars or other environmental sensors, hence flight paths are changed, or, if it exists, anti-icing/de-icing systems are used. This work aims at the detection and identification of airframe icing based on statistical properties of aircraft dynamics and reconfigurable control protecting aircraft from hazardous icing conditions. In this paper, aircraft icing identification based on neural networks is investigated. Following icing identification, reconfigurable control is applied for protecting the aircraft from hazardous icing conditions.

Effects of Low Flying Aircraft on Archaeological Structures

DTIC Science & Technology

1988-09-26

obtained from direct observation of aircraft overflights at one particular site, Ixng House, near Kayenta . Arizona. 2. THE SITE The Long House site is...located approximately 20 km southwest of Kayenta , Arizona, as shown in Figure 1. The Long House ruins were part of an extensive Anasazi agricultural...community that was (Received for Publication 22 September 1988) 1 UTAH COLORADO ARIZONANEW MEXICO LONG HOUSE I FARMINGTON SITE KAYENTA I CHACO CANYON

The atmospheric effects of stratospheric aircraft: A current consensus

NASA Technical Reports Server (NTRS)

Douglass, A. R.; Carroll, M. A.; Demore, W. B.; Holton, J. R.; Isaksen, I. S. A.; Johnston, H. S.; Ko, M. K. W.

1991-01-01

In the early 1970's, a fleet of supersonic aircraft flying in the lower stratosphere was proposed. A large fleet was never built for economic, political, and environmental reasons. Technological improvements may make it economically feasible to develop supersonic aircraft for current markets. Some key results of earlier scientific programs designed to assess the impact of aircraft emissions on stratospheric ozone are reviewed, and factors that must be considered to assess the environmental impact of aircraft exhaust are discussed. These include the amount of nitrogen oxides injected in the stratosphere, horizontal transport, and stratosphere/troposphere assessment models are presented. Areas in which improvements in scientific understanding and model representation must be made to reduce the uncertainty in model calculations are identified.

Cessna UC–78 Bobcat at the Aircraft Engine Research Laboratory

NASA Image and Video Library

1943-10-21

The Aircraft Engine Research Laboratory acquired the five-seat Cessna UC–78 in March 1943 to maintain the proficiency of its pilots. The UC–78 was referred to as the “Bamboo Bomber” because of its wooden wings and tail and its fabric-covered steel body. The aircraft was produced in 1939 for civilian use, but the military soon began ordering them as training aircraft. The military also began using the aircraft for personnel transport. Cessna produced over 4600 of the aircraft for the military during World War II. The National Advisory Committee for Aeronautics’ (NACA) pilot Howard Lilly flew the UC–78 extensively during its residency in Cleveland. The aircraft was used for ferrying staff members to nearby locations and helping the pilots keep their flying hours up. The UC–78 was transferred in October 1945.

AutoGNI, the Robot Under the Aircraft Floor: An Automated System for Sampling Giant Aerosol Particles by Impaction in the Free Airstream Outside a Research Aircraft

NASA Astrophysics Data System (ADS)

Jensen, J. B.; Schwenz, K.; Aquino, J.; Carnes, J.; Webster, C.; Munnerlyn, J.; Wissman, T.; Lugger, T.

2017-12-01

Giant sea-salt aerosol particles, also called Giant Cloud Condensation Nuclei (GCCN), have been proposed as a means of rapidly forming precipitation sized drizzle drops in warm marine clouds (e.g., Jensen and Nugent, 2017). Such rare particles are best sampled from aircraft in air below cloud base, where normal laser optical instruments have too low sample volume to give statistically significant samples of the large particle tail. An automated sampling system (the AutoGNI) has been built to operate from inside a pressurized aircraft. Under the aircraft floor, a pressurized vessel contains 32 custom-built polycarbonate microscope slides. Using robotics with 5 motor drives and 18 positioning switches, the AutoGNI can take slides from their holding cassettes, pass them onto a caddy in an airfoil that extends 200 mm outside the aircraft, where they are exposed in the free airstream, thus avoiding the usual problems with large particle losses in air intakes. Slides are typically exposed for 10-30 s in the marine boundary layer, giving sample volumes of about 100-300 L or more. Subsequently the slides are retracted into the pressure vessel, stored and transported for laboratory microscope image analysis, in order to derive size-distribution histograms. While the aircraft is flying, the AutoGNI system is remotely controlled from a laptop on the ground, using an encrypted commercial satellite connection to the NSF/NCAR GV research aircraft's main server, and onto the AutoGNI microprocessor. The sampling of such GCCN is becoming increasingly important in order to provide complete input data for model calculations of aerosol-cloud interactions and their feedbacks in climate prediction. The AutoGNI has so far been sampling sea-salt GCCN in the Magellan Straight during the 2016 ORCAS project and over the NW Pacific during the 2017 ARISTO project, both from the NSF/NCAR GV research aircraft. Sea-salt particle sizes of 1.4 - 32 μm dry diameter have been observed.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

With the snow-covered San Gabriel Mountains as a backdrop and a motorcycle-mounted chase crew alongside, a quarter-scale model of the Centurion solar-powered flying wing soars over El Mirage Dry Lake on an early test flight in March 1997. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Framed by wispy contrails left by passing jets high above, a quarter-scale model of the Centurion solar-electric flying wing shows off its graceful lines during a March 1997 test flight at El Mirage Dry Lake in California's Mojave Desert. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Trailed by a van carrying the remote pilot and observers, a radio-controlled quarter-scale model of the Centurion solar-electric flying wing makes a low pass over El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Silhouetted under a bright blue sky, a quarter-scale model of the Centurion solar-powered flying wing shows off its internal rib structure as it floats over the El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

Flight test results for the Daedalus and Light Eagle human powered aircraft

NASA Technical Reports Server (NTRS)

Sullivan, R. Bryan; Zerweckh, Siegfried H.

1988-01-01

The results of the flight test program of the Daedalus and Light Eagle human powered aircraft in the winter of 1987/88 are given. The results from experiments exploring the Light Eagle's rigid body and structural dynamics are presented. The interactions of these dynamics with the autopilot design are investigated. Estimates of the power required to fly the Daedalus aircraft are detailed. The system of sensors, signal conditioning boards, and data acquisition equipment used to record the flight data is also described. In order to investigate the dynamics of the aircraft, flight test maneuvers were developed to yield maximum data quality from the point of view of estimating lateral and longitudinal stability derivatives. From this data, structural flexibility and unsteady aerodynamics have been modeled in an ad hoc manner and are used to augment the equations of motion with flexibility effects. Results of maneuvers that were flown are compared with the predictions from the flexibility model. To extend the ad hoc flexibility model, a fully flexible aeroelastic model has been developed. The model is unusual in the approximate equality of many structural natural frequencies and the importance of unsteady aerodynamic effects. the Gossamer Albatross. It is hypothesized that this inverse ground effect is caused by turbulence in the Earth's boundary layer. The diameters of the largest boundary layer eddies (which represent most of the turbulent kinetic energy) are proportional to altitude; thus, closer to the ground, the energy in the boundary layer becomes concentrated in eddies of smaller and smaller diameter. Eventually the eddies become sufficiently small (approximately 0.5 cm) that they trip the laminar boundary layer on the wing. As a result, a greater percentage of the wing area is covered with turbulent flow. Consequently the aircraft's drag and the pow er required both increase as the aircraft flies closer to the ground. The results of the flight test program are

Daedalus Project's Light Eagle - Human powered aircraft

NASA Technical Reports Server (NTRS)

1987-01-01

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

Relation between leaching characteristics of heavy metals and physical properties of fly ashes from typical municipal solid waste incinerators.

PubMed

Ni, Peng; Li, Hailong; Zhao, Yongchun; Zhang, Junying; Zheng, Chuguang

2017-09-01

Due to the alkalinity and high concentration of potentially hazardous heavy metals, fly ash from a municipal solid waste (MSW) incinerator is classified as hazardous waste, which should be of particular concern. Physical and chemical characterizations of the contrasted fly ashes were investigated to explore the relation between leaching characteristics of heavy metals and physical properties of fly ashes. The results showed that CaClOH, NaCl, Ca(OH) 2 , KCl and SiO 2 were primary mineral compositions in the MSWI fly ashes, and the particle size distribution of fly ash ranged between 10 μm and 300 μm. The smaller the particle size distribution of fly ash, the larger the BET-specific surface area, which was beneficial to the leaching of heavy metals. As a result of various pores, it easily accumulated heavy metals as well. The leaching tests exhibited a high leachability of heavy metals and the leaching concentration of Pb in almost all of the fly ash samples went far beyond the Standard for Pollution Control on the Landfill Site of Municipal Solid Waste. Thereupon, it is necessary to establish proper disposal systems and management strategies for environmental protection based on the characteristics of MSW incineration (MSWI) fly ash in China.

X-36 Tailless Fighter Agility Research Aircraft in flight

NASA Image and Video Library

1997-10-30

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

Design of a spanloader cargo aircraft

NASA Technical Reports Server (NTRS)

Weisshaar, Terrence A.

1989-01-01

The design features of an aircraft capable of fulfilling a long haul, high capacity cargo mission are described. This span-loading aircraft, or flying wing, is capable of carrying extremely large payloads and is expected to be in demand to replace the slow-moving cargo ships currently in use. The spanloader seeks to reduce empty weight by eliminating the aircraft fuselage. Disadvantages are the thickness of the cargo-containing wing, and resulting stability and control problems. The spanloader presented here has a small fuselage, low-aspect ratio wings, winglets, and uses six turbofan engines for propulsion. It will have a payload capacity of 300,000 pounds plus 30 first class passengers and 6 crew members. Its projected market is transportation of freight from Europe and the U.S.A. to countries in the Pacific Basin. Cost estimates support its economic feasibility.

Dynamic imaging and RCS measurements of aircraft

NASA Astrophysics Data System (ADS)

Jain, Atul; Patel, Indu

1995-01-01

Results on radar cross section (RCS) measurements and inverse synthetic aperture radar images of a Mooney 231 aircraft using a ground-to-air measurement system (GTAMS) and a KC-135 airplane using an airborne radar are presented. The Mooney 231 flew in a controlled path in both clockwise and counterclockwise orbits, and successively with the gear down, flaps in the take-off position and with the speed brakes up. The data indicates that RCS pattern measurements from both ground-based and airborne radar of flying aircraft are useful and that the inverse synthetic aperture radar (ISAR) images obtained are valuable for signature diagnostics.

Aircraft-Induced Hole Punch and Canal Clouds

NASA Astrophysics Data System (ADS)

Heymsfield, A. J.; Kennedy, P.; Massie, S. T.; Schmitt, C. G.; Wang, Z.; Haimov, S.; Rangno, A.

2009-12-01

The production of holes and channels in altocumulus clouds by two commercial turboprop aircraft is documented for the first time. An unprecedented data set combining in situ measurements from microphysical probes with remote sensing measurements from cloud radar and lidar, all operating from the NSF/NCAR C130 aircraft, as well as ground-based NOAA and CSU radars, is used to describe the radar/lidar properties of a hole punch cloud and channel and the ensuing ice microphysical properties and structure of the ice column that subsequently developed. Ice particle production by commercial turboprop aircraft climbing through clouds much warmer than the regions where contrails are produced has the potential to modify significantly the cloud microphysical properties and effectively seed them under some conditions. Jet aircraft may also be producing hole punch clouds when flying through altocumulus with supercooled droplets at heights lower than their normal cruise altitudes where contrails can form. Commercial aircraft therefore can generate ice and affect the clouds at temperatures as much as 30°C warmer than the -40°C contrail formation threshold temperature.

NASA aircraft trailing vortex research

NASA Technical Reports Server (NTRS)

Mcgowan, W. A.

1971-01-01

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.

Exploiting Formation Flying for Fuel Saving Supersonic Oblique Wing Aircraft

DTIC Science & Technology

2007-07-01

used and developed during recent wing / winglet / morphing design programmes (Refs.13-14). By exploiting this method, we have assessed the aerodynamics...with winglets ”, AIAA-2006-3460. 25th Applied Aero Conference, San Francisco, June 2006. 15. NANGIA, R.K., PALMER, M.E., “Formation Flying of Commercial

Why They Fly: An Expectancy-Based Analysis of the Factors that Motivate Commissioned Army Aviators to Gain Flying Experience

DTIC Science & Technology

2007-06-15

Davis Highway, Suite 1204, Arlington, VA 22202- 4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be... Moroze and Snow (1999) controlled flight into terrain (CFIT) accidents, where the crew unintentionally flies the aircraft into the earth or a man...number of CFIT accidents for the pilots with more flight hours was based on the behavior patterns that result from experience ( Moroze & Snow, 1999

Access improvement to aircraft passengers' hand luggage.

PubMed

Alberda, W; Kampinga, O; Kassels, R; van Kester, R; Noriega, J; Vink, P

2015-01-01

Efficient use of space and passenger comfort in aircraft interiors are major issues. There is not much research available about the flying experience regarding passengers' personal belongings. The objective of this study is to explore concepts within the current aircraft seats which improve the passenger experience related to their personal belongings like wallets, mobile phones and laptops. Through on-site observations, interviews and online questionnaires, data regarding the number of personal belongings taken into the airplane and opinions about access to hand luggage were gathered. These data were used to develop different concepts to optimize the aircraft interior, which were evaluated by passengers. Almost every passenger carries a phone (88%), wallet (94%), travel documents (98%) and keys (76%) with them and they like to have these stored close by. Passengers rate the concept that provides integrated storage in the tray table of the aircraft seat the best. Extra storage possibility in the table-tray seems a promising solution according to the passengers.

Design criteria for flightpath and airspeed control for the approach and landing of STOL aircraft

NASA Technical Reports Server (NTRS)

Franklin, J. A.; Innis, R. C.; Hardy, G. H.; Stephenson, J. D.

1982-01-01

A flight research program was conducted to assess requirements for flightpath and airspeed control for glide-slope tracking during a precision approach and for flare control, particularly as applied to powered-lift, short takeoff and landing (STOL) aircraft. Ames Research Center's Augmentor Wing Research Aircraft was used to fly approaches on a 7.5 deg glide slope to landings on a 30 X 518 m (100 X 1700 ft) STOL runway. The dominant aircraft response characteristics determined were flightpath overshoot, flightpath-airspeed coupling, and initial flightpath response time. The significant contribution to control of the landing flare using pitch attitude was the short-term flightpath response. The limiting condition for initial flightpath response time for flare control with thrust was also identified. It is possible to define flying-qualities design criteria for glide-slope and flare control based on the aforementioned response characteristics.

Adaptation of aeronautical engines to high altitude flying

NASA Technical Reports Server (NTRS)

Kutzbach, K

1923-01-01

Issues and techniques relative to the adaptation of aircraft engines to high altitude flight are discussed. Covered here are the limits of engine output, modifications and characteristics of high altitude engines, the influence of air density on the proportions of fuel mixtures, methods of varying the proportions of fuel mixtures, the automatic prevention of fuel waste, and the design and application of air pressure regulators to high altitude flying. Summary: 1. Limits of engine output. 2. High altitude engines. 3. Influence of air density on proportions of mixture. 4. Methods of varying proportions of mixture. 5. Automatic prevention of fuel waste. 6. Design and application of air pressure regulators to high altitude flying.

Study and Evaluation of Current and Future Aircraft Loaders

DTIC Science & Technology

1986-08-01

Tigers Airlines JFK Airport , NY 10 Feb 86 Boeing Military Airplane Co. Boeing Commercial Airplane Co. Seattle, WA 11 Feb 86 Korean Airlines LAX, CA 12...Nash Boeing Aircraft Co., Seattle, WA Mr. J. Nelson JFK Airport , NY Mr. P. O’Brien ASD/ENCA Wright-Patterson AFB, OH Mr. C. Outran HQ AFLC/DSTMA...Locations 15 Oct 85 TWA Freight Terminal Laimbert Int’l Airport , St. Louis, mO 22 Nov 85 Lockheed - Georgia Aircraft Co. Marietta, GA 13 Dec 85 Flying

Flying SATS Higher Volume Operations: Training, Lessons Learned, and Pilots' Experiences

NASA Technical Reports Server (NTRS)

Conway, Sheila; Williams, Dan; Adams, Catherine; Consiglio, Maria; Murdoch, Jennifer

2005-01-01

Developments in aviation, including new surveillance technologies and quicker, more economical small aircraft, have been identified as driving factors in a potential expansion of the use of non-towered, non-radar airports. The Small Aircraft Transportation System (SATS) project has developed the Higher Volume Operations (HVO) concept that enables pilots to safely arrive and depart these airports in instrument conditions at an increased rate as compared to today's procedures. This is achieved by transferring some traffic management tasks to centralized, ground-based automation, while assigning others to participating pilots aided by on-board tools. This paper describes strategies and lessons learned while training pilots to fly these innovative operations. Pilot approaches to using the experimental displays and dynamic altering systems during training are discussed. Potential operational benefits as well as pit-falls and frustrations expressed by subjects while learning to fly these new procedures are presented. Generally, pilots were comfortable with the procedures and the training process, and expressed interest in its near-term implementation.

A bio-inspired flying robot sheds light on insect piloting abilities.

PubMed

Franceschini, Nicolas; Ruffier, Franck; Serres, Julien

2007-02-20

When insects are flying forward, the image of the ground sweeps backward across their ventral viewfield and forms an "optic flow," which depends on both the groundspeed and the groundheight. To explain how these animals manage to avoid the ground by using this visual motion cue, we suggest that insect navigation hinges on a visual-feedback loop we have called the optic-flow regulator, which controls the vertical lift. To test this idea, we built a micro-helicopter equipped with an optic-flow regulator and a bio-inspired optic-flow sensor. This fly-by-sight micro-robot can perform exacting tasks such as take-off, level flight, and landing. Our control scheme accounts for many hitherto unexplained findings published during the last 70 years on insects' visually guided performances; for example, it accounts for the fact that honeybees descend in a headwind, land with a constant slope, and drown when travelling over mirror-smooth water. Our control scheme explains how insects manage to fly safely without any of the instruments used onboard aircraft to measure the groundheight, groundspeed, and descent speed. An optic-flow regulator is quite simple in terms of its neural implementation and just as appropriate for insects as it would be for aircraft.

Challenge to Aviation: Hatching a Leaner Pterosauer. [Improving Commercial Aircraft Design for Greater Fuel Efficiency

NASA Technical Reports Server (NTRS)

Moss, F. E.

1975-01-01

Modifications in commercial aircraft design, particularly the development of lighter aircraft, are discussed as effective means of reducing aviation fuel consumption. The modifications outlined include: (1) use of the supercritical wing; (2) generation of the winglet; (3) production and flight testing of composite materials; and, (4) implementation of fly-by-wire control systems. Attention is also given to engineering laminar air flow control, improving cargo payloads, and adapting hydrogen fuels for aircraft use.

Civil air transport: A fresh look at power-by-wire and fly-by-light

NASA Technical Reports Server (NTRS)

Sundberg, Gale R.

1991-01-01

Power-by-wire (PBW) is a key element under subsonic transport flight systems technology with potential savings of over 10 percent in operating empty weight and in fuel consumption compared to today's transport aircraft. The PBW technology substitutes electrical actuation in place of centralized hydraulics, uses internal starter-motor/generators and eliminates the need for variable engine bleed air to supply cabin comfort. The application of advanced fiber optics to the electrical power system controls, to built-in-test (BIT) equipment, and to fly-by-light (FBL) flight controls provides additional benefits in lightning and high energy radio frequency (HERF) immunity over existing mechanical or even fly-by-wire controls. The program plan is reviewed and a snapshot is given of the key technologies and their benefits to all future aircraft, both civil and military.

Process modeling KC-135 aircraft

NASA Technical Reports Server (NTRS)

Workman, Gary L.

1991-01-01

Instrumentation will be provided for KC-135 aircraft which will provide a quantitative measure of g-level variation during parabolic flights and its effect on experiments which demonstrate differences in results obtained with differences in convective flow. The flight apparatus will provide video recording of the effects of the g-level variations on varying fluid samples. The apparatus will be constructed to be available to fly on the KC-135 during most missions.

Space Shuttle Discovery Fly-By

NASA Image and Video Library

2012-04-17

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) flies over the Steven F. Udvar-Hazy Center, Tuesday, April 17, 2012, in Washington. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Smithsonian Institution/Eric Long)

Space Shuttle flying qualities and flight control system assessment study, phase 2

NASA Technical Reports Server (NTRS)

Myers, T. T.; Johnston, D. E.; Mcruer, D. T.

1983-01-01

A program of flying qualities experiments as part of the Orbiter Experiments Program (OEX) is defined. Phase 1, published as CR-170391, reviewed flying qualities criteria and shuttle data. The review of applicable experimental and shuttle data to further define the OEX plan is continued. An unconventional feature of this approach is the use of pilot strategy model identification to relate flight and simulator results. Instrumentation, software, and data analysis techniques for pilot model measurements are examined. The relationship between shuttle characteristics and superaugmented aircraft is established. STS flights 1 through 4 are reviewed from the point of view of flying qualities. A preliminary plan for a coordinated program of inflight and simulator research is presented.

Space Shuttle Endeavour flies by Johnson Space Center

NASA Image and Video Library

2008-12-11

JSC2008-E-154359 (11 Dec. 2008) --- The Space Shuttle Endeavour flies over the Clear Lake area and the Johnson Space Center after having spent the night at a stopover in Tarrant County, while mounted on a modified Boeing 747 shuttle carrier aircraft. Endeavour landed in California on Nov. 30 and was en route back to Florida. This photo, taken from the rear station of a NASA T-38 aircraft, shows the main part of the 1625-acre JSC site. The extremely clear weather allows viewing all the way to Houston's central business district. Harris County Domed Stadium and the Houston NFL franchise's stadium are visible in the upper left quadrant of the photo.

Aural detection of small propeller-driven aircraft

DOT National Transportation Integrated Search

1987-10-31

The Federal Aviation Administration (FAA) has conducted numerous flight tests of small propeller-driven aircraft in support of developing aircraft noise regulations. Those test typically measured ground-level noise resulting from high power/high RPM ...

Lightning effects on the NASA F-8 digital-fly-by-wire airplane

NASA Technical Reports Server (NTRS)

Plumer, J. A.; Fisher, F. A.; Walko, L. C.

1975-01-01

The effects of lightning on a Digital Fly-By-Wire (DFBW)aircraft control system were investigated. The aircraft was a NASA operated F-8 fitted with a modified Apollo guidance computer. Current pulses similar in waveshape to natural lightning, but lower in amplitude, were injected into the aircraft. Measurements were made of the voltages induced on the DFBW circuits, the total current induced on the bundles of wires, the magnetic field intensity inside the aircraft, and the current density on the skin of the aircraft. Voltage measurements were made in both the line-to-ground and line-to-line modes. Voltages measured at the non-destructive test level were then scaled upward to determine how much would be produced by actual lightning. A 200,000 ampere severe lightning flash would produce between 40 and 2000 volts in DFBW circuits. Some system components are expected to be vulnerable to these voltages.

Optimizing Aircraft Trajectories with Multiple Cruise Altitudes in the Presence of Winds

NASA Technical Reports Server (NTRS)

Ng, Hok K.; Sridhar, Banavar; Grabbe, Shon

2014-01-01

This study develops a trajectory optimization algorithm for approximately minimizing aircraft travel time and fuel burn by combining a method for computing minimum-time routes in winds on multiple horizontal planes, and an aircraft fuel burn model for generating fuel-optimal vertical profiles. It is applied to assess the potential benefits of flying user-preferred routes for commercial cargo flights operating between Anchorage, Alaska and major airports in Asia and the contiguous United States. Flying wind optimal trajectories with a fuel-optimal vertical profile reduces average fuel burn of international flights cruising at a single altitude by 1-3 percent. The potential fuel savings of performing en-route step climbs are not significant for many shorter domestic cargo flights that have only one step climb. Wind-optimal trajectories reduce fuel burn and travel time relative to the flight plan route by up to 3 percent for the domestic cargo flights. However, for trans-oceanic traffic, the fuel burn savings could be as much as 10 percent. The actual savings in operations will vary from the simulation results due to differences in the aircraft models and user defined cost indices. In general, the savings are proportional to trip length, and depend on the en-route wind conditions and aircraft types.

Cross-Polar Aircraft Trajectory Optimization and Potential Climate Impact

NASA Technical Reports Server (NTRS)

Sridhar, Banavar; Chen, Neil; Ng, Hok

2011-01-01

Cross-Polar routes offer new opportunities for air travel markets. Transpolar flights reduce travel times, fuel burns, and associated environmental emissions by flying direct paths between many North American and Asian cities. This study evaluates the potential benefits of flying wind-optimal polar routes and assessed their potential impact on climate change. An optimization algorithm is developed for transpolar flights to generate wind-optimal trajectories that minimize climate impact of aircraft, in terms of global warming potentials (relative to warming by one kg of CO2) of several types of emissions, while avoiding regions of airspace that facilitate persistent contrail formation. Estimations of global warming potential are incorporated into the objective function of the optimization algorithm to assess the climate impact of aircraft emissions discharged at a given location and altitude. The regions of airspace with very low ambient temperature and areas favorable to persistent contrail formation are modeled as undesirable regions that aircraft should avoid and are formulated as soft state constraints. The fuel burn and climate impact of cross-polar air traffic flying various types of trajectory including flightplan, great circle, wind-optimal, and contrail-avoidance are computed for 15 origin-destination pairs between major international airports in the U.S. and Asia. Wind-optimal routes reduce average fuel burn of flight plan routes by 4.4% on December 4, 2010 and 8.0% on August 7, 2010, respectively. The tradeoff between persistent contrail formation and additional global warming potential of aircraft emissions is investigated with and without altitude optimization. Without altitude optimization, the reduction in contrail travel times is gradual with increase in total fuel consumption. When altitude is optimized, a one percent increase in additional global warming potential, a climate impact equivalent to that of 4070kg and 4220kg CO2 emission, reduces 135

Conceptual Final Paper on the Preliminary Design of an Oblique Flying Wing SST

NASA Technical Reports Server (NTRS)

Van der Velden, Alexander J. M.

1987-01-01

A conceptual Oblique Flying Wing Supersonic Transport Aircraft (OFW, or surfplane because of its shape) was first proposed in 1957. It was reintroduced in 1987 in view of the emerging technology of artificial stabilization. This paper is based on the performance and economics study of an M2 B747-100B replacement aircraft. In order to make a fair comparison of this configuration with the B747, an end-sixties structural technology level is assumed. It is shown that a modern stability and control system can balance the aircraft and smooth out gusts, and that the OFW configuration equals or outperforms the B747 in speed, economy and comfort.

Flying Boresight for Advanced Testing and Calibration of Tracking Antennas and Flight Path Simulations

NASA Astrophysics Data System (ADS)

Hafner, D.

2015-09-01

The application of ground-based boresight sources for calibration and testing of tracking antennas usually entails various difficulties, mostly due to unwanted ground effects. To avoid this problem, DLR MORABA developed a small, lightweight, frequency-adjustable S-band boresight source, mounted on a small remote-controlled multirotor aircraft. Highly accurate GPS-supported, position and altitude control functions allow both, very steady positioning of the aircraft in mid-air, and precise waypoint-based, semi-autonomous flights. In contrast to fixed near-ground boresight sources this flying setup enables to avoid obstructions in the Fresnel zone between source and antenna. Further, it minimizes ground reflections and other multipath effects which can affect antenna calibration. In addition, the large operating range of a flying boresight simplifies measurements in the far field of the antenna and permits undisturbed antenna pattern tests. A unique application is the realistic simulation of sophisticated flight paths, including overhead tracking and demanding trajectories of fast objects such as sounding rockets. Likewise, dynamic tracking tests are feasible which provide crucial information about the antenna pedestal performance — particularly at high elevations — and reveal weaknesses in the autotrack control loop of tracking antenna systems. During acceptance tests of MORABA's new tracking antennas, a manned aircraft was never used, since the Flying Boresight surpassed all expectations regarding usability, efficiency, and precision. Hence, it became an integral part of MORABA's standard antenna setup and calibration procedures.

Flying in a flock comes at a cost in pigeons.

PubMed

Usherwood, James R; Stavrou, Marinos; Lowe, John C; Roskilly, Kyle; Wilson, Alan M

2011-06-22

Flying birds often form flocks, with social, navigational and anti-predator implications. Further, flying in a flock can result in aerodynamic benefits, thus reducing power requirements, as demonstrated by a reduction in heart rate and wingbeat frequency in pelicans flying in a V-formation. But how general is an aerodynamic power reduction due to group-flight? V-formation flocks are limited to moderately steady flight in relatively large birds, and may represent a special case. What are the aerodynamic consequences of flying in the more usual 'cluster' flock? Here we use data from innovative back-mounted Global Positioning System (GPS) and 6-degrees-of-freedom inertial sensors to show that pigeons (1) maintain powered, banked turns like aircraft, imposing dorsal accelerations of up to 2g, effectively doubling body weight and quadrupling induced power requirements; (2) increase flap frequency with increases in all conventional aerodynamic power requirements; and (3) increase flap frequency when flying near, particularly behind, other birds. Therefore, unlike V-formation pelicans, pigeons do not gain an aerodynamic advantage from flying in a flock. Indeed, the increased flap frequency, whether due to direct aerodynamic interactions or requirements for increased stability or control, suggests a considerable energetic cost to flight in a tight cluster flock.

Flying in a flock comes at a cost in pigeons

PubMed Central

Usherwood, James R.; Stavrou, Marinos; Lowe, John C.; Roskilly, Kyle; Wilson, Alan M.

2011-01-01

Flying birds often form flocks, with social1, navigational2 and anti-predator3 implications. Further, flying in a flock can result in aerodynamic benefits, thus reducing power requirements4, as demonstrated by a reduction in heart rate and wingbeat frequency in pelicans flying in a V-formation5. But how general is an aerodynamic power reduction due to group-flight? V-formation flocks are limited to moderately steady flight in relatively large birds, and may represent a special case. What are the aerodynamic consequences of flying in the more usual ‘cluster’ 6,7 flock? Here, we use data from innovative back-mounted GPS and 6 degree of freedom inertial sensors to show that pigeons 1) maintain powered, banked turns like aircraft, imposing dorsal accelerations of up to 2g, effectively doubling body weight and quadrupling induced power requirements; 2) increase flap frequency with increases in all conventional aerodynamic power requirements; and 3) increase flap frequency when flying near, particularly behind, other birds. Therefore, unlike V-formation pelicans, pigeons do not gain an aerodynamic advantage from flying in a flock; indeed, the increased flap frequency – whether due to direct aerodynamic interactions or requirements for increased stability or control – suggests a considerable energetic cost to flight in a tight cluster flock. PMID:21697946

Civil air transport: A fresh look at power-by-wire and fly-by-light

NASA Technical Reports Server (NTRS)

Sundberg, Gale R.

1990-01-01

Power-by-wire (PBW) is a key element under subsonic transport flight systems technology with potential savings of over 10 percent in gross take-off-weight and in fuel consumption compared to today's transport aircraft. The PBW technology substitutes electrical actuation in place of centralized hydraulics, uses internal starter-motor/generators and eliminates the need for variable engine bleed air to supply cabin comfort. The application of advanced fiber optics to the electrical power system controls, to built-in-test (BITE) equipment, and to fly-by-light (FBL) flight controls provides additional benefits in lightning and high energy radio frequency (HERF) immunity over existing mechanical or even fly-by-wire controls. The program plan is reviewed and a snapshot is given of the key technologies and their benefits to all future aircraft, both civil and military.

Path changing methods applied to the 4-D guidance of STOL aircraft.

DOT National Transportation Integrated Search

1971-11-01

Prior to the advent of large-scale commercial STOL service, some challenging navigation and guidance problems must be solved. Proposed terminal area operations may require that these aircraft be capable of accurately flying complex flight paths, and ...

Engine-propeller power plant aircraft community noise reduction key methods

NASA Astrophysics Data System (ADS)

Moshkov P., A.; Samokhin V., F.; Yakovlev A., A.

2018-04-01

Basic methods of aircraft-type flying vehicle engine-propeller power plant noise reduction were considered including single different-structure-and-arrangement propellers and piston engines. On the basis of a semiempirical model the expressions for blade diameter and number effect evaluation upon propeller noise tone components under thrust constancy condition were proposed. Acoustic tests performed at Moscow Aviation institute airfield on the whole qualitatively proved the obtained ratios. As an example of noise and detectability reduction provision a design-and-experimental estimation of propeller diameter effect upon unmanned aircraft audibility boundaries was performed. Future investigation ways were stated to solve a low-noise power plant design problem for light aircraft and unmanned aerial vehicles.

Dryden B-52 Launch Aircraft in Flight over Dryden

NASA Technical Reports Server (NTRS)

1996-01-01

NASA's venerable B-52 mothership flies over the main building at the Dryden Flight Research Center, Edwards, California. 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 has also been 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

Flight dynamic investigations of flying wing with winglet configured unmanned aerial vehicle

NASA Astrophysics Data System (ADS)

Ro, Kapseong

2006-05-01

A swept wing tailless vehicle platform is well known in the radio control (RC) and sailing aircraft community for excellent spiral stability during soaring or thermaling, while exhibiting no Dutch roll behavior at high speed. When an unmanned aerial vehicle (UAV) is subjected to fly a mission in a rugged mountainous terrain where air current or thermal up-drift is frequently present, this is great aerodynamic benefit over the conventional cross-tailed aircraft which requires careful balance between lateral and directional stability. Such dynamic characteristics can be studied through vehicle dynamic modeling and simulation, but it requires configuration aerodynamic data through wind tunnel experiments. Obtaining such data is very costly and time consuming, and it is not feasible especially for low cost and dispensable UAVs. On the other hand, the vehicle autonomy is quite demanding which requires substantial understanding of aircraft dynamic characteristics. In this study, flight dynamics of an UAV platform based on flying wing with a large winglet was investigated through analytical modeling and numerical simulation. Flight dynamic modeling software and experimental formulae were used to obtain essential configuration aerodynamic characteristics, and linear flight dynamic analysis was carried out to understand the effect of wing sweep angle and winglet size on the vehicle dynamic characteristics.

Space Shuttle Discovery Fly-Over

NASA Image and Video Library

2012-04-17

Spectators watch as space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) flies over the National Air and Space Museum’s Steven F. Udvar-Hazy Center, Tuesday, April 17, 2012, in Chantilly, Va. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

Design and Fabrication of Flying Saucer Utilizing Coanda Effect

NASA Astrophysics Data System (ADS)

Aabid, Abdul; Khan, S. A.

2018-05-01

Coanda effect is used in several engineering applications with distinctive designs and structures. It is also applied in aircrafts flying at low speeds for a comfortable ride. In this paper, we have designed and modelled Coanda effect in terms of a flying saucer. The fabrication was done by means of structural and electronic components. Electrical motor was used as a propeller to take off and land vertically (VTOL) along with hovering capability. The rotor disc diameter is smaller than the bulbous body unlike a helicopter which makes to fly very stable. Control flaps were used to regulate the path by altering the flow over the streamlined body. The model was then tested with a remote control. Numerical Simulation of the tesla turbine was done using ANSYS 14.5 software and displacements were obtained by applying different forces on designed model. CATIA V5 was used to analyse the shaft of the model to get minimum value of torque at which the shaft starts to deform.

Aircraft control forces and EMG activity in a C-130 Hercules during strength-critical maneuvers.

PubMed

Hewson, D J; McNair, P J; Marshall, R N

2001-03-01

The force levels required to operate aircraft controls should be readily generated by pilots, without undue fatigue or exertion. However, maximum pilot applied forces, as specified in aircraft design standards, were empirically derived from the subjective comments of test pilots, and may not be applicable for the majority of pilots. Further, experienced RNZAF Hercules flying instructors have indicated that endurance and fatigue are problems for Hercules pilots. The aim of this study was to quantify aircraft control forces during emergency maneuvers in a Hercules aircraft and compare these forces with design standards. In addition, EMG data were recorded as an indicator of muscle fatigue during flight. Six subjects were tested in a C-130 Hercules aircraft. The maneuvers performed were low-level dynamic flight, one engine-off straight-and-level flight, and a two-engines-off simulated approach. The variables recorded were pilot-applied forces and EMG activity. Left rudder pedal force and vastus lateralis activity were both significantly greater during engine-off maneuvers than during low-level dynamic flight (p < 0.05). Maximum aircraft control forces for all controls were within 10% of the design standards. The mean EMG activity across all muscles and maneuvers was 26% MVC, with a peak of 61% MVC in vastus lateralis during the two-engine-off approach. The median frequency of the vastus lateralis EMG signal decreased 13.0% and 16.0% for the one engine-off and two-engine-off maneuvers, respectively. The forces required to fly a Hercules aircraft during emergency maneuvers are similar to the aircraft design standards. However, the levels of vastus lateralis muscle activation observed during the engine-off maneuvers can be sustained for approximately 1 min only. Thus, if two engines fail more than 1 min before landing, pilots may have to alternate control of the aircraft to share the workload and enable the aircraft to land safely.

Escorting commercial aircraft to reduce the MANPAD threat

NASA Astrophysics Data System (ADS)

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

2005-11-01

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

Mechanical Backup For Fly-By-Wire Control System

NASA Technical Reports Server (NTRS)

Stewart, Eric C.

1992-01-01

Mechanical device eliminates need for redundant fly-by-wire subsystems. Main components are two linkages. One connected to control column in conventional, reversible control system. Other slides inside first linkage and connected to pilot's control wheel. In addition to aircraft applications, design used in control systems in which computer control desirable but safety backup systems required; for example, in boat rudders, engine controls in boats and automobiles, and controls in construction equipment.

Social-Ecological Soundscapes: Examining Aircraft-Harvester-Caribou Conflict in Arctic Alaska

NASA Astrophysics Data System (ADS)

Stinchcomb, Taylor R.

As human development expands across the Arctic, it is crucial to carefully assess the impacts to remote natural ecosystems and to indigenous communities that rely on wild resources for nutritional and cultural wellbeing. Because indigenous communities and wildlife populations are interdependent, assessing how human activities impact traditional harvest practices can advance our understanding of the human dimensions of wildlife management. Indigenous communities across Arctic Alaska have expressed concern over the last four decades that low-flying aircraft interfere with their traditional harvest practices. For example, communities often have testified that aircraft disturb caribou (Rangifer tarandus) and thereby reduce harvest opportunities. Despite this longstanding concern, little research exists on the extent of aircraft activity in Arctic Alaska and on how aircraft affect the behavior and perceptions of harvesters. Therefore, the overarching goal of my research was to highlight the importance of aircraft-harvester conflict in Arctic Alaska and begin to address the issue using a scientific and community-driven approach. In Chapter 1, I demonstrated that conflict between aircraft and indigenous harvesters in Arctic Alaska is a widespread, understudied, and complex issue. By conducting a meta-analysis of the available literature, I quantified the deficiency of scientific knowledge about the impacts of aircraft on rural communities and traditional harvest practices in the Arctic. My results indicated that no peer-reviewed literature has addressed the conflict between low-flying aircraft and traditional harvesters in Arctic Alaska. I speculated that the scale over which aircraft, rural communities, and wildlife interact limits scientists' ability to determine causal relationships and therefore detracts from their interest in researching the human dimension of this social-ecological system. Innovative research approaches like soundscape ecology could begin to

Small Aircraft Transportation System, Higher Volume Operations Concept: Off-Nominal Operations

NASA Technical Reports Server (NTRS)

Abbott, Terence S.; Consiglio, Maria C.; Baxley, Brian T.; Williams, Daniel M.; Conway, Sheila R.

2005-01-01

This document expands the Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept to include off-nominal conditions. The general philosophy underlying the HVO concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA). During periods of poor weather, a block of airspace would be established around designated non-towered, non-radar airports. Aircraft flying enroute to a SATS airport would be on a standard instrument flight rules flight clearance with Air Traffic Control providing separation services. Within the SCA, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Previous work developed the procedures for normal HVO operations. This document provides details for off-nominal and emergency procedures for situations that could be expected to occur in a future SCA.

Cross-Polar Aircraft Trajectory Optimization and the Potential Climate Impact

NASA Technical Reports Server (NTRS)

Ng, Hok K.; Sridhar, Banavar; Grabbe, Shon; Chen, Neil

2011-01-01

Cross-Polar routes offer new opportunities for air travel markets. Transpolar flights reduce travel times, fuel burns, and associated environmental emissions by flying direct paths between many North American and Asian cities. This study evaluates the potential benefits of flying wind-optimal polar routes and assessed their potential impact on climate change. An optimization algorithm is developed for transpolar flights to generate wind-optimal trajectories that minimize climate impact of aircraft, in terms of global warming potentials (relative to warming by one kg of CO2) of several types of emissions, while avoiding regions of airspace that facilitate persistent contrail formation. Estimations of global warming potential are incorporated into the objective function of the optimization algorithm to assess the climate impact of aircraft emissions discharged at a given location and altitude. The regions of airspace with very low ambient temperature and areas favorable to persistent contrail formation are modeled as undesirable regions that aircraft should avoid and are formulated as soft state constraints. The fuel burn and climate impact of cross-polar air traffic flying various types of trajectory including flight plan, great circle, wind-optimal, and contrail-avoidance are computed for 15 origin-destination pairs between major international airports in the U.S. and Asia. Wind-optimal routes reduce average fuel burn of flight plan routes by 4.4% on December 4, 2010 and 8.0% on August 7, 2010, respectively. The tradeoff between persistent contrail formation and additional global warming potential of aircraft emissions is investigated with and without altitude optimization. Without altitude optimization, the reduction in contrail travel times is gradual with increase in total fuel consumption. When altitude is optimized, a one percent increase in additional global warming potential, a climate impact equivalent to that of 4070kg and 4220kg CO2 emission, reduces 135

Space Shuttle Discovery DC Fly-Over

NASA Image and Video Library

2012-04-17

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) flies near the U.S. Capitol, Tuesday, April 17, 2012, in Washington. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Michael Porterfield)

Space Shuttle Discovery DC Fly-Over

NASA Image and Video Library

2012-04-17

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) flies over the Steven F. Udvar-Hazy Center, Tuesday, April 17, 2012, in Washington. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Robert Markowitz)

Space Shuttle Discovery DC Fly-Over

NASA Image and Video Library

2012-04-16

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) flies near the U.S. Capitol, Tuesday, April 17, 2012, in Washington. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Rebecca Roth)

Space Shuttle Discovery DC Fly-Over

NASA Image and Video Library

2012-04-17

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) flies near the U.S. Capitol, Tuesday, April 17, 2012, in Washington. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Bill Ingalls)

Discovering the flight autostabilizer of fruit flies by inducing aerial stumbles.

PubMed

Ristroph, Leif; Bergou, Attila J; Ristroph, Gunnar; Coumes, Katherine; Berman, Gordon J; Guckenheimer, John; Wang, Z Jane; Cohen, Itai

2010-03-16

Just as the Wright brothers implemented controls to achieve stable airplane flight, flying insects have evolved behavioral strategies that ensure recovery from flight disturbances. Pioneering studies performed on tethered and dissected insects demonstrate that the sensory, neurological, and musculoskeletal systems play important roles in flight control. Such studies, however, cannot produce an integrative model of insect flight stability because they do not incorporate the interaction of these systems with free-flight aerodynamics. We directly investigate control and stability through the application of torque impulses to freely flying fruit flies (Drosophila melanogaster) and measurement of their behavioral response. High-speed video and a new motion tracking method capture the aerial "stumble," and we discover that flies respond to gentle disturbances by accurately returning to their original orientation. These insects take advantage of a stabilizing aerodynamic influence and active torque generation to recover their heading to within 2 degrees in < 60 ms. To explain this recovery behavior, we form a feedback control model that includes the fly's ability to sense body rotations, process this information, and actuate the wing motions that generate corrective aerodynamic torque. Thus, like early man-made aircraft and modern fighter jets, the fruit fly employs an automatic stabilization scheme that reacts to short time-scale disturbances.

A model for rotorcraft flying qualities studies

NASA Technical Reports Server (NTRS)

Mittal, Manoj; Costello, Mark F.

1993-01-01

This paper outlines the development of a mathematical model that is expected to be useful for rotorcraft flying qualities research. A computer model is presented that can be applied to a range of different rotorcraft configurations. The algorithm computes vehicle trim and a linear state-space model of the aircraft. The trim algorithm uses non linear optimization theory to solve the nonlinear algebraic trim equations. The linear aircraft equations consist of an airframe model and a flight control system dynamic model. The airframe model includes coupled rotor and fuselage rigid body dynamics and aerodynamics. The aerodynamic model for the rotors utilizes blade element theory and a three state dynamic inflow model. Aerodynamics of the fuselage and fuselage empennages are included. The linear state-space description for the flight control system is developed using standard block diagram data.

Modelling and extraction technique for micro-doppler signature of aircraft rotor blades

NASA Astrophysics Data System (ADS)

Praveen, N.; Valarmathi, J.

2017-11-01

The process of detecting and distinguishing between different aircrafts has been a major point of interest in Defence applications. Micro-Doppler effect is one such phenomenon unique for aircrafts with different rotor dynamics and design. In this paper, we focus on deducing a mathematical model for micro-Doppler signature, of aircraft rotor blades assumed to be rotating in a plane perpendicular to the flying direction, induced on the incident radar signal. Also, we use the Wigner-Ville Distribution (WVD) to extract this signature from the radar return. This mathematical model is compared with the simulation results obtained from MATLAB, to validate the results and show the accurateness of the developed model.

CID Aircraft slap-down

NASA Technical Reports Server (NTRS)

1984-01-01

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

Fly-ear inspired acoustic sensors for gunshot localization

NASA Astrophysics Data System (ADS)

Liu, Haijun; Currano, Luke; Gee, Danny; Yang, Benjamin; Yu, Miao

2009-05-01

The supersensitive ears of the parasitoid fly Ormia ochracea have inspired researchers to develop bio-inspired directional microphone for sound localization. Although the fly ear is optimized for localizing the narrow-band calling song of crickets at 5 kHz, experiments and simulation have shown that it can amplify directional cues for a wide frequency range. In this article, a theoretical investigation is presented to study the use of fly-ear inspired directional microphones for gunshot localization. Using an equivalent 2-DOF model of the fly ear, the time responses of the fly ear structure to a typical shock wave are obtained and the associated time delay is estimated by using cross-correlation. Both near-field and far-field scenarios are considered. The simulation shows that the fly ear can greatly amplify the time delay by ~20 times, which indicates that with an interaural distance of only 1.2 mm the fly ear is able to generate a time delay comparable to that obtained by a conventional microphone pair with a separation as large as 24 mm. Since the parameters of the fly ear structure can also be tuned for muzzle blast and other impulse stimulus, fly-ear inspired acoustic sensors offers great potential for developing portable gunshot localization systems.

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

NASA Technical Reports Server (NTRS)

Howell, Charles T., III

2011-01-01

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.

Recommended procedures for measuring aircraft noise and associated parameters

NASA Technical Reports Server (NTRS)

Marsh, A. H.

1977-01-01

Procedures are recommended for obtaining experimental values of aircraft flyover noise levels (and associated parameters). Specific recommendations are made for test criteria, instrumentation performance requirements, data-acquisition procedures, and test operations. The recommendations are based on state-of-the-art measurement capabilities available in 1976 and are consistent with the measurement objectives of the NASA Aircraft Noise Prediction Program. The recommendations are applicable to measurements of the noise produced by an airplane flying subsonically over (or past) microphones located near the surface of the ground. Aircraft types covered by the recommendations are fixed-wing airplanes powered by turbojet or turbofan engines and using conventional aerodynamic means for takeoff and landing. Various assumptions with respect to subsequent data processing and analysis were made (and are described) and the recommended measurement procedures are compatible with the assumptions. Some areas where additional research is needed relative to aircraft flyover noise measurement techniques are also discussed.

Survival of insects in the wheel bays of a Boeing 747B aircraft on flights between tropical and temperate airports

PubMed Central

Russell, R. C.

1987-01-01

Mosquitos (Culex quinquefasciatus), house flies (Musca domestica), and flour beetles (Tribolium confusum) located in cages within the wheel bays of a Boeing 747B aircraft, survived travel on the following normal commercial routes: Sydney—Melbourne; Melbourne—Singapore; Singapore—Bangkok; Bangkok—Singapore; and Singapore—Melbourne. Survival of all three species was high, averaging 84% for mosquitos and higher for flies (93%) and beetles (>99%). Although external temperatures were -42 °C to -54 °C for aircraft cruising at 10 700-11 900 m, minimum temperatures within the wheel bays ranged from +8 °C to +25 °C. PMID:3501345

Small Aircraft RF Interference Path Loss

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

2007-01-01

Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to better interference risk assessment.

Nitrogen oxides at the UTLS: Combining observations from research aircraft and in-service aircraft

NASA Astrophysics Data System (ADS)

Ziereis, Helmut; Stratmann, Greta; Schlager, Hans; Gottschaldt, Klaus-Dirk; Rauthe-Schöch, Armin; Zahn, Andreas; Hoor, Peter; van, Peter

2016-04-01

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 lifetime and their variety of sources there is still a high uncertainty about the abundance of nitrogen oxides in the UTLS. Dedicated aircraft campaigns aim to study specific atmospheric questions like lightning, long range transport or aircraft emissions. Usually, within a short time period comprehensive measurements are performed within a more or less restricted region. Therefore, especially trace constituents like nitrogen oxides with short lifetime and a variety of different sources are not represented adequately. On the other hand, routine measurements from in-service aircraft allow observations over longer time periods and larger regions. However, it is nearly impossible to influence the scheduling of in-service aircraft and thereby time and space of the observations. Therefore, the combination of dedicated aircraft campaigns and routine observations might supplement each other. For this study we combine nitrogen oxides data sets obtained with the IAGOS-CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) flying laboratory and with the German research aircraft HALO (High altitude and long range research aircraft). Data have been acquired within the IAGOS-CARIBIC project on a monthly base using a Lufthansa Airbus A340-600 since December 2004. About four flights are performed each month covering predominantly northern mid-latitudes. Additional flights have been conducted to destinations in South America and South Africa. Since 2012 HALO has been operational. Nitrogen oxides measurements have been performed during six missions covering mid latitudes, tropical as well as Polar

Crew systems and flight station concepts for a 1995 transport aircraft

NASA Technical Reports Server (NTRS)

Sexton, G. A.

1983-01-01

Aircraft functional systems and crew systems were defined for a 1995 transport aircraft through a process of mission analysis, preliminary design, and evaluation in a soft mockup. This resulted in a revolutionary pilot's desk flight station design featuring an all-electric aircraft, fly-by-wire/light flight and thrust control systems, large electronic color head-down displays, head-up displays, touch panel controls for aircraft functional systems, voice command and response systems, and air traffic control systems projected for the 1990s. The conceptual aircraft, for which crew systems were designed, is a generic twin-engine wide-body, low-wing transport, capable of worldwide operation. The flight control system consists of conventional surfaces (some employed in unique ways) and new surfaces not used on current transports. The design will be incorporated into flight simulation facilities at NASA-Langley, NASA-Ames, and the Lockheed-Georgia Company. When interfaced with advanced air traffic control system models, the facilities will provide full-mission capability for researching issues affecting transport aircraft flight stations and crews of the 1990s.

Flight Testing the Rotor Systems Research Aircraft (RSRA)

NASA Technical Reports Server (NTRS)

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

1983-01-01

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.

Altus I aircraft on lakebed

NASA Technical Reports Server (NTRS)

1997-01-01

The remotely-piloted Altus I aircraft climbs away after takeoff from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, were designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet. The Altus II, the first of the two craft to be completed, made its first flight on May 1, 1996. With its engine augmented by a single-stage turbocharger, the Altus II reached an altitude of 37,000 ft during its first series of development flights at Dryden in Aug., 1996. In Oct. of that year, the Altus II was flown in an Atmospheric Radiation Measurement study for the Department of Energy's Sandia National Laboratory in Oklahoma. During the course of those flights, the Altus II set a single-flight endurance record for remotely-operated aircraft of more than 26 hours. The Altus I, completed in 1997, flew a series of development flights at Dryden that summer. Those test flights culminated with the craft reaching an altitude of 43,500 ft while carrying a simulated 300-lb payload, a record for an unmanned aircraft powered by a piston engine augmented with a single-stage turbocharger. The Altus II sustained an altitudeof 55,000 feet for four hours in 1999. A pilot in a control station on the ground flies the

Digital Fly-By-Wire Flight Control Validation Experience

NASA Technical Reports Server (NTRS)

Szalai, K. J.; Jarvis, C. R.; Krier, G. E.; Megna, V. A.; Brock, L. D.; Odonnell, R. N.

1978-01-01

The experience gained in digital fly-by-wire technology through a flight test program being conducted by the NASA Dryden Flight Research Center in an F-8C aircraft is described. The system requirements are outlined, along with the requirements for flight qualification. The system is described, including the hardware components, the aircraft installation, and the system operation. The flight qualification experience is emphasized. The qualification process included the theoretical validation of the basic design, laboratory testing of the hardware and software elements, systems level testing, and flight testing. The most productive testing was performed on an iron bird aircraft, which used the actual electronic and hydraulic hardware and a simulation of the F-8 characteristics to provide the flight environment. The iron bird was used for sensor and system redundancy management testing, failure modes and effects testing, and stress testing in many cases with the pilot in the loop. The flight test program confirmed the quality of the validation process by achieving 50 flights without a known undetected failure and with no false alarms.

Bayesian Software Health Management for Aircraft Guidance, Navigation, and Control

NASA Technical Reports Server (NTRS)

Schumann, Johann; Mbaya, Timmy; Menghoel, Ole

2011-01-01

Modern aircraft, both piloted fly-by-wire commercial aircraft as well as UAVs, more and more depend on highly complex safety critical software systems with many sensors and computer-controlled actuators. Despite careful design and V&V of the software, severe incidents have happened due to malfunctioning software. In this paper, we discuss the use of Bayesian networks (BNs) to monitor the health of the on-board software and sensor system, and to perform advanced on-board diagnostic reasoning. We will focus on the approach to develop reliable and robust health models for the combined software and sensor systems.

Space Shuttle Discovery DC Fly-Over

NASA Image and Video Library

2012-04-17

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) is seen from Top of the Town in Arlington, Virginia as it flies near the U.S. Capitol, Tuesday, April 17, 2012, in Washington. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Chris Gunn)

Space Shuttle Discovery DC Fly-Over

NASA Image and Video Library

2012-04-17

Space shuttle Discovery, mounted atop a NASA 747 Shuttle Carrier Aircraft (SCA) is seen as it flies near the U.S. Capitol, Tuesday, April 17, 2012, in Washington. Discovery, the first orbiter retired from NASA’s shuttle fleet, completed 39 missions, spent 365 days in space, orbited the Earth 5,830 times, and traveled 148,221,675 miles. NASA will transfer Discovery to the National Air and Space Museum to begin its new mission to commemorate past achievements in space and to educate and inspire future generations of explorers. Photo Credit: (NASA/Smithsonian Institution/Harold Dorwin)

System level airworthiness tool: A comprehensive approach to small unmanned aircraft system airworthiness

NASA Astrophysics Data System (ADS)

Burke, David A.

One of the pillars of aviation safety is assuring sound engineering practices through airworthiness certification. As Unmanned Aircraft Systems (UAS) grow in popularity, the need for airworthiness standards and verification methods tailored for UAS becomes critical. While airworthiness practices for large UAS may be similar to manned aircraft, it is clear that small UAS require a paradigm shift from the airworthiness practices of manned aircraft. Although small in comparison to manned aircraft these aircraft are not merely remote controlled toys. Small UAS may be complex aircraft flying in the National Airspace System (NAS) over populated areas for extended durations and beyond line of sight of the operators. A comprehensive systems engineering framework for certifying small UAS at the system level is needed. This work presents a point based tool that evaluates small UAS by rewarding good engineering practices in design, analysis, and testing. The airworthiness requirements scale with vehicle size and operational area, while allowing flexibility for new technologies and unique configurations.

Operational Concept for Flight Crews to Participate in Merging and Spacing of Aircraft

NASA Technical Reports Server (NTRS)

Baxley, Brian T.; Barmore, Bryan E.; Abbott, Terence S.; Capron, William R.

2006-01-01

The predicted tripling of air traffic within the next 15 years is expected to cause significant aircraft delays and create a major financial burden for the airline industry unless the capacity of the National Airspace System can be increased. One approach to improve throughput and reduce delay is to develop new ground tools, airborne tools, and procedures to reduce the variance of aircraft delivery to the airport, thereby providing an increase in runway throughput capacity and a reduction in arrival aircraft delay. The first phase of the Merging and Spacing Concept employs a ground based tool used by Air Traffic Control that creates an arrival time to the runway threshold based on the aircraft s current position and speed, then makes minor adjustments to that schedule to accommodate runway throughput constraints such as weather and wake vortex separation criteria. The Merging and Spacing Concept also employs arrival routing that begins at an en route metering fix at altitude and continues to the runway threshold with defined lateral, vertical, and velocity criteria. This allows the desired spacing interval between aircraft at the runway to be translated back in time and space to the metering fix. The tool then calculates a specific speed for each aircraft to fly while enroute to the metering fix based on the adjusted land timing for that aircraft. This speed is data-linked to the crew who fly this speed, causing the aircraft to arrive at the metering fix with the assigned spacing interval behind the previous aircraft in the landing sequence. The second phase of the Merging and Spacing Concept increases the timing precision of the aircraft delivery to the runway threshold by having flight crews using an airborne system make minor speed changes during enroute, descent, and arrival phases of flight. These speed changes are based on broadcast aircraft state data to determine the difference between the actual and assigned time interval between the aircraft pair. The

B-52 Launch Aircraft in Flight

NASA Technical Reports Server (NTRS)

2001-01-01

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

Utilization of western coal fly ash in construction of highways in the Midwest

DOT National Transportation Integrated Search

2000-03-01

Coal burning utilities in the Midwest are increasingly using sub-bituminous coal from Wyoming. These utilities typically produce fly ash, which, because of its high calcium oxide content, may be classified as Class C fly ash. These ashes are characte...

Vortex-Free Flight Corridors for Aircraft Executing Compressed Landing Operations

NASA Technical Reports Server (NTRS)

Rossow, Vernon J.

2006-01-01

A factor that limits airport arrival and departure rates is the need to wait between operations for the wake vortices of preceding aircraft to decay to a safe level. As airport traffic demand increases, creative methods will be needed to overcome the limitations caused by the hazard posed by vortex wakes so that airport capacities can be increased. The problem addressed here is the design of vortex-free trajectories for aircraft as they fly from their cruise altitudes down to their final approach paths and to a landing. The guidelines presented recommend that the flight path of each aircraft in a group executing nearly-simultaneous landings be spaced far enough apart laterally along organized flight paths so that the vortex wakes of preceding aircraft will not intrude into the airspace to be used by following aircraft. An example is presented as to how a combination of straight lines and circular arcs is able to provide each aircraft in a group with a vortex-free trajectory so that all are able to safely form the pattern needed for nearly simultaneous landings on a set of closely-spaced parallel runways. Although the guidelines me described for aircraft on approach, they are also applicable to departure, and to en route operations.

Flying qualities design criteria applicable to supersonic cruise aircraft

NASA Technical Reports Server (NTRS)

Chalk, C. R.

1980-01-01

A comprehensive set of flying qualities design criteria was prepared for use in the supersonic cruise research program. The framework for stating the design criteria is established and design criteria are included which address specific failures, approach to dangerous flight conditions, flight at high angle of attack, longitudinal and lateral directional stability and control, the primary flight control system, and secondary flight controls. Examples are given of lateral directional design criteria limiting lateral accelerations at the cockpit, time to roll through 30 deg of bank, and time delay in the pilot's command path. Flight test data from the Concorde certification program are used to substantiate a number of the proposed design criteria.

Pilot heart rate during in-flight simulated instrument approaches in a general aviation aircraft.

DOT National Transportation Integrated Search

1970-04-01

Eight instrument rated pilots with flying experience ranging from 600 to 12,271 hours each flew 10 simulated ILS instrument approaches in a single engine, general aviation aircraft equipped with a primary flight display arranged in conventional 'T' c...

Collision avoidance for aircraft in abort landing

NASA Astrophysics Data System (ADS)

Mathwig, Jarret

We study the collision avoidance between two aircraft flying in the same vertical plane: a host aircraft on a glide path and an intruder aircraft on a horizontal trajectory below that of the host aircraft and heading in the opposite direction. Assuming that the intruder aircraft is uncooperative, the host aircraft executes an optimal abort landing maneuver: it applies maximum thrust setting and maximum angle of attack lifting the flight path over the original path, thereby increasing the timewise minimum distance between the two aircraft and, in this way, avoiding the potential collision. In the presence of weak constraints on the aircraft and/or the environment, the angle of attack must be brought to the maximum value and kept there until the maximin point is reached. On the other hand, in the presence of strong constraints on the aircraft and the environment, desaturation of the angle of attack might have to take place before the maximin point is reached. This thesis includes four parts. In the first part, after an introduction and review of the available literature, we reformulate and solve the one-subarc Chebyshev maximin problem as a two-subarc Bolza-Pontryagin problem in which the avoidance and the recovery maneuvers are treated simultaneously. In the second part, we develop a guidance scheme (gamma guidance) capable of approximating the optimal trajectory in real time. In the third part, we present the algorithms employed to solve the one-subarc and two-subarc problems. In the fourth part, we decompose the two-subarc Bolza-Pontryagin problem into two one-subarc problems: the avoidance problem and the recovery problem, to be solved in sequence; remarkably, for problems where the ratio of total maneuver time to avoidance time is sufficiently large (≥5), this simplified procedure predicts accurately the location of the maximin point as well as the maximin distance.

Longitudinal Handling Qualities of the Tu-144LL Airplane and Comparisons With Other Large, Supersonic Aircraft

NASA Technical Reports Server (NTRS)

Cox, Timothy H.; Marshall, Alisa

2000-01-01

Four flights have been conducted using the Tu-144LL supersonic transport aircraft with the dedicated objective of collecting quantitative data and qualitative pilot comments. These data are compared with the following longitudinal flying qualities criteria: Neal-Smith, short-period damping, time delay, control anticipation parameter, phase delay (omega(sp)*T(theta(2))), pitch bandwidth as a function of time delay, and flight path as a function of pitch bandwidth. Determining the applicability of these criteria and gaining insight into the flying qualities of a large, supersonic aircraft are attempted. Where appropriate, YF-12, XB-70, and SR-71 pilot ratings are compared with the Tu-144LL results to aid in the interpretation of the Tu-144LL data and to gain insight into the application of criteria. The data show that approach and landing requirements appear to be applicable to the precision flightpath control required for up-and-away flight of large, supersonic aircraft. The Neal-Smith, control anticipation parameter, and pitch-bandwidth criteria tend to correlate with the pilot comments better than the phase delay criterion, omega(sp)*T(theta(2)). The data indicate that the detrimental flying qualities implication of decoupled pitch-attitude and flightpath responses occurring for high-speed flight may be mitigated by requiring the pilot to close the loop on flightpath or vertical speed.

Alkali-aggregate reactivity of typical siliceious glass and carbonate rocks in alkali-activated fly ash based geopolymers

NASA Astrophysics Data System (ADS)

Lu, Duyou; Liu, Yongdao; Zheng, Yanzeng; Xu, Zhongzi; Shen, Xiaodong

2013-08-01

For exploring the behaviour of alkali-aggregate reactivity (AAR) in alkali-activated geopolymeric materials and assessing the procedures for testing AAR in geopolymers, the expansion behaviour of fly ash based geopolymer mortars with pure silica glass and typical carbonate rocks were studied respectively by curing at various conditions, i.e. 23°C and 38°C with relative humidity over 95%, immersed in 1M NaOH solution at 80°C. Results show that, at various curing conditions, neither harmful ASR nor harmful ACR was observed in geopolymers with the criteria specified for OPC system. However, with the change of curing conditions, the geopolymer binder and reactive aggregates may experience different reaction processes leading to quite different dimensional changes, especially with additional alkalis and elevated temperatures. It suggests that high temperature with additional alkali for accelerating AAR in traditional OPC system may not appropriate for assessing the alkali-aggregate reactivity behaviour in geopolymers designed for normal conditions. On the other hand, it is hopeful to control the dimensional change of geopolymer mortar or concrete by selecting the type of aggregates and the appropriate curing conditions, thus changing the harmful AAR in OPC into beneficial AAR in geopolymers and other alkali-activated cementitious systems.

A neural based intelligent flight control system for the NASA F-15 flight research aircraft

NASA Technical Reports Server (NTRS)

Urnes, James M.; Hoy, Stephen E.; Ladage, Robert N.; Stewart, James

1993-01-01

A flight control concept that can identify aircraft stability properties and continually optimize the aircraft flying qualities has been developed by McDonnell Aircraft Company under a contract with the NASA-Dryden Flight Research Facility. This flight concept, termed the Intelligent Flight Control System, utilizes Neural Network technology to identify the host aircraft stability and control properties during flight, and use this information to design on-line the control system feedback gains to provide continuous optimum flight response. This self-repairing capability can provide high performance flight maneuvering response throughout large flight envelopes, such as needed for the National Aerospace Plane. Moreover, achieving this response early in the vehicle's development schedule will save cost.

Fly-by-Light Advanced Systems Hardware (FLASH) program

NASA Astrophysics Data System (ADS)

Bedoya, Carlos A.

1995-05-01

hundreds of MHz are available. Applications of fiber optic buses would then result in the reduction of wires and connections because of reduction in the number of buses needed for information transfer due to the fact that a large number of different signals can be sent across one fiber by multiplexing each signal. The Advanced Research Projects Agency (ARPA) Technology Reinvestment Project (TRP) Fly-by-Light Advanced Systems Hardware (FLASH) program addresses the development of Fly-by-Light Technology in order to apply the benefits of fiber optics to military and commercial aircraft.

CID Aircraft post-impact lakebed skid

NASA Technical Reports Server (NTRS)

1984-01-01

Moments after hitting and sliding through the wing openers the aircraft burst into flame, with a spectacular fireball seen emanating from the right inboard engine area. 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

Radiation protection aspects of the cosmic radiation exposure of aircraft crew.

PubMed

Bartlett, D T

2004-01-01

Aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 60, the European Union introduced a revised Basic Safety Standards Directive, which included exposure to natural sources of ionising radiation, including cosmic radiation, as occupational exposure. The revised Directive has been incorporated into laws and regulations in the European Union Member States. Where the assessment of the occupational exposure of aircraft crew is necessary, the preferred approach to monitoring is by the recording of staff flying times and calculated route doses. Route doses are to be validated by measurements. This paper gives the general background, and considers the radiation protection aspects of the cosmic radiation exposure of aircraft crew, with the focus on the situation in Europe.

Discovering the flight autostabilizer of fruit flies by inducing aerial stumbles

PubMed Central

Ristroph, Leif; Bergou, Attila J.; Ristroph, Gunnar; Coumes, Katherine; Berman, Gordon J.; Guckenheimer, John; Wang, Z. Jane; Cohen, Itai

2010-01-01

Just as the Wright brothers implemented controls to achieve stable airplane flight, flying insects have evolved behavioral strategies that ensure recovery from flight disturbances. Pioneering studies performed on tethered and dissected insects demonstrate that the sensory, neurological, and musculoskeletal systems play important roles in flight control. Such studies, however, cannot produce an integrative model of insect flight stability because they do not incorporate the interaction of these systems with free-flight aerodynamics. We directly investigate control and stability through the application of torque impulses to freely flying fruit flies (Drosophila melanogaster) and measurement of their behavioral response. High-speed video and a new motion tracking method capture the aerial “stumble,” and we discover that flies respond to gentle disturbances by accurately returning to their original orientation. These insects take advantage of a stabilizing aerodynamic influence and active torque generation to recover their heading to within 2° in < 60 ms. To explain this recovery behavior, we form a feedback control model that includes the fly’s ability to sense body rotations, process this information, and actuate the wing motions that generate corrective aerodynamic torque. Thus, like early man-made aircraft and modern fighter jets, the fruit fly employs an automatic stabilization scheme that reacts to short time-scale disturbances. PMID:20194789

Nitrous oxide pollution from aircraft to increase by 2050

NASA Astrophysics Data System (ADS)

Bhattacharya, Atreyee

2012-09-01

The transportation industry is not only one of the biggest sources of air pollution and a significant player in greenhouse gas-induced global warming, but, as a new study shows, the industry could also be responsible for episodes of ozone (O3 ) pollution, particularly over the United States and northern Europe. Combustion of fuel in cars, shipping vessels, and low-flying aircraft produce nitrogen oxides (NOx), which not only decrease the lifetime of greenhouse gases such as methane but also react with other molecules in the atmosphere to form tropospheric O3, another, more lethal, air pollutant. Hauglustaine and Koff used a global three-dimensional chemistry-climate model to investigate how different components of the transportation industry—cars, ships, and low-flying aircraft—would contribute to NOx pollution over the next few decades under several projected emission scenarios. They found that as road transportation stagnates or even declines due to stricter regulations and congestion, NOx emissions from cars will decrease over time. However, aircraft will increase in number and could contribute between 25% and 48% of NOx emissions, which will be most severe over the United States and Europe—two regions with the highest growth rate in commercial aviation.

Program for narrow-band analysis of aircraft flyover noise using ensemble averaging techniques

NASA Technical Reports Server (NTRS)

Gridley, D.

1982-01-01

A package of computer programs was developed for analyzing acoustic data from an aircraft flyover. The package assumes the aircraft is flying at constant altitude and constant velocity in a fixed attitude over a linear array of ground microphones. Aircraft position is provided by radar and an option exists for including the effects of the aircraft's rigid-body attitude relative to the flight path. Time synchronization between radar and acoustic recording stations permits ensemble averaging techniques to be applied to the acoustic data thereby increasing the statistical accuracy of the acoustic results. Measured layered meteorological data obtained during the flyovers are used to compute propagation effects through the atmosphere. Final results are narrow-band spectra and directivities corrected for the flight environment to an equivalent static condition at a specified radius.

China’s Approach to Technology Acquisition: Part 1. The Aircraft Industry

DTIC Science & Technology

1975-02-01

the possible purchase of used BOAC Bristol Britannia 102 airliners, l even test-flying a demonstration aircraft in England. In the fall of 1963...small contingents of Dutch State Mines technicians who will accompany each of the three plants as they are delivered. The huge cold-strip steel

A brain-machine interface to navigate a mobile robot in a planar workspace: enabling humans to fly simulated aircraft with EEG.

PubMed

Akce, Abdullah; Johnson, Miles; Dantsker, Or; Bretl, Timothy

2013-03-01

This paper presents an interface for navigating a mobile robot that moves at a fixed speed in a planar workspace, with noisy binary inputs that are obtained asynchronously at low bit-rates from a human user through an electroencephalograph (EEG). The approach is to construct an ordered symbolic language for smooth planar curves and to use these curves as desired paths for a mobile robot. The underlying problem is then to design a communication protocol by which the user can, with vanishing error probability, specify a string in this language using a sequence of inputs. Such a protocol, provided by tools from information theory, relies on a human user's ability to compare smooth curves, just like they can compare strings of text. We demonstrate our interface by performing experiments in which twenty subjects fly a simulated aircraft at a fixed speed and altitude with input only from EEG. Experimental results show that the majority of subjects are able to specify desired paths despite a wide range of errors made in decoding EEG signals.

Coupled nonlinear aeroelasticity and flight dynamics of fully flexible aircraft

NASA Astrophysics Data System (ADS)

Su, Weihua

This dissertation introduces an approach to effectively model and analyze the coupled nonlinear aeroelasticity and flight dynamics of highly flexible aircraft. A reduced-order, nonlinear, strain-based finite element framework is used, which is capable of assessing the fundamental impact of structural nonlinear effects in preliminary vehicle design and control synthesis. The cross-sectional stiffness and inertia properties of the wings are calculated along the wing span, and then incorporated into the one-dimensional nonlinear beam formulation. Finite-state unsteady subsonic aerodynamics is used to compute airloads along lifting surfaces. Flight dynamic equations are then introduced to complete the aeroelastic/flight dynamic system equations of motion. Instead of merely considering the flexibility of the wings, the current work allows all members of the vehicle to be flexible. Due to their characteristics of being slender structures, the wings, tail, and fuselage of highly flexible aircraft can be modeled as beams undergoing three dimensional displacements and rotations. New kinematic relationships are developed to handle the split beam systems, such that fully flexible vehicles can be effectively modeled within the existing framework. Different aircraft configurations are modeled and studied, including Single-Wing, Joined-Wing, Blended-Wing-Body, and Flying-Wing configurations. The Lagrange Multiplier Method is applied to model the nodal displacement constraints at the joint locations. Based on the proposed models, roll response and stability studies are conducted on fully flexible and rigidized models. The impacts of the flexibility of different vehicle members on flutter with rigid body motion constraints, flutter in free flight condition, and roll maneuver performance are presented. Also, the static stability of the compressive member of the Joined-Wing configuration is studied. A spatially-distributed discrete gust model is incorporated into the time simulation

A technique for integrating engine cycle and aircraft configuration optimization

NASA Technical Reports Server (NTRS)

Geiselhart, Karl A.

1994-01-01

A method for conceptual aircraft design that incorporates the optimization of major engine design variables for a variety of cycle types was developed. The methodology should improve the lengthy screening process currently involved in selecting an appropriate engine cycle for a given application or mission. The new capability will allow environmental concerns such as airport noise and emissions to be addressed early in the design process. The ability to rapidly perform optimization and parametric variations using both engine cycle and aircraft design variables, and to see the impact on the aircraft, should provide insight and guidance for more detailed studies. A brief description of the aircraft performance and mission analysis program and the engine cycle analysis program that were used is given. A new method of predicting propulsion system weight and dimensions using thermodynamic cycle data, preliminary design, and semi-empirical techniques is introduced. Propulsion system performance and weights data generated by the program are compared with industry data and data generated using well established codes. The ability of the optimization techniques to locate an optimum is demonstrated and some of the problems that had to be solved to accomplish this are illustrated. Results from the application of the program to the analysis of three supersonic transport concepts installed with mixed flow turbofans are presented. The results from the application to a Mach 2.4, 5000 n.mi. transport indicate that the optimum bypass ratio is near 0.45 with less than 1 percent variation in minimum gross weight for bypass ratios ranging from 0.3 to 0.6. In the final application of the program, a low sonic boom fix a takeoff gross weight concept that would fly at Mach 2.0 overwater and at Mach 1.6 overland is compared with a baseline concept of the same takeoff gross weight that would fly Mach 2.4 overwater and subsonically overland. The results indicate that for the design mission

Small Aircraft RF Interference Path Loss Measurements

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

2007-01-01

Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to more meaningful interference risk assessment.

Aircraft Spacings that Produce a Vortex-Free Region Below Flight Formation

NASA Technical Reports Server (NTRS)

Rossow, Vernon J.

2000-01-01

Theoretical estimates are presented for the motion of vortex wakes shed by multiple aircraft flying in close formation. The purpose of the theoretical study was to determine whether the spacings between adjacent aircraft in close formations could be designed so that the lift-generated vortices being trailed would move upward rather than downward. In this way, a region below the formation is produced that is free of vortices. It was found that aircraft can be arranged in formations so that the inboard wake vortices all move upward rather than downward. The two outboard vortices travel downward at a greatly reduced velocity that depends on the number of aircraft in the formation. If the desired motions are to be produced, the lateral spacings between adjacent aircraft centerlines must be between 1.1 and 1.5 wingspans, and the vertical spacings between -0.025 and -0.15 wingspans. Since the range of acceptable spacings is small, it is recommended that the position accuracy between aircraft in the formation be kept within about + or - 0.01 wingspan of the center of acceptable spacings so that aircraft meandering do not cause unwanted vortex excursions. It was also found that, if the in-trail spacings between adjacent aircraft are more than 4 wingspans, the foregoing vertical spacings must be adjusted to allow for the additional downward travel of the vortices shed by leading aircraft.

Flying at no mechanical energy cost: disclosing the secret of wandering albatrosses.

PubMed

Sachs, Gottfried; Traugott, Johannes; Nesterova, Anna P; Dell'Omo, Giacomo; Kümmeth, Franz; Heidrich, Wolfgang; Vyssotski, Alexei L; Bonadonna, Francesco

2012-01-01

Albatrosses do something that no other birds are able to do: fly thousands of kilometres at no mechanical cost. This is possible because they use dynamic soaring, a flight mode that enables them to gain the energy required for flying from wind. Until now, the physical mechanisms of the energy gain in terms of the energy transfer from the wind to the bird were mostly unknown. Here we show that the energy gain is achieved by a dynamic flight manoeuvre consisting of a continually repeated up-down curve with optimal adjustment to the wind. We determined the energy obtained from the wind by analysing the measured trajectories of free flying birds using a new GPS-signal tracking method yielding a high precision. Our results reveal an evolutionary adaptation to an extreme environment, and may support recent biologically inspired research on robotic aircraft that might utilize albatrosses' flight technique for engineless propulsion.

A Simple Two Aircraft Conflict Resolution Algorithm

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.

1999-01-01

Conflict detection and resolution methods are crucial for distributed air-ground traffic management in which the crew in the cockpit, dispatchers in operation control centers and air traffic controllers in the ground-based air traffic management facilities share information and participate in the traffic flow and traffic control imctions.This paper describes a conflict detection and a conflict resolution method. The conflict detection method predicts the minimum separation and the time-to-go to the closest point of approach by assuming that both the aircraft will continue to fly at their current speeds along their current headings. The conflict resolution method described here is motivated by the proportional navigation algorithm. It generates speed and heading commands to rotate the line-of-sight either clockwise or counter-clockwise for conflict resolution. Once the aircraft achieve a positive range-rate and no further conflict is predicted, the algorithm generates heading commands to turn back the aircraft to their nominal trajectories. The speed commands are set to the optimal pre-resolution speeds. Six numerical examples are presented to demonstrate the conflict detection and resolution method.

Aircraft Readiness under Budget Constraint, Its Relationship with Logistics Resources; the Spare Parts Component, a Model for the Portuguese Air Force.

DTIC Science & Technology

1986-12-01

Additional Expenditures for Baseline Scenario .. 75 IV. Total Expenditures for Fiscal Year 1987 for the CHIPMUNK Aircraft Type ... e,........... 76 V. Source...flying hour program for the CHIPMUNK aircraft type. From the relevant information concerned with the fiscal year 1986, the following data elements were...validation goal is to compare model results with the level of budget assigned to this aircraft type. For the fiscal year of 1986 a 20,000,000$00

Transport aircraft accident dynamics

NASA Technical Reports Server (NTRS)

Cominsky, A.

1982-01-01

A study was carried out of 112 impact survivable jet transport aircraft accidents (world wide) of 27,700 kg (60,000 lb.) aircraft and up extending over the last 20 years. This study centered on the effect of impact and the follow-on events on aircraft structures and was confined to the approach, landing and takeoff segments of the flight. The significant characteristics, frequency of occurrence and the effect on the occupants of the above data base were studied and categorized with a view to establishing typical impact scenarios for use as a basis of verifying the effectiveness of potential safety concepts. Studies were also carried out of related subjects such as: (1) assessment of advanced materials; (2) human tolerance to impact; (3) merit functions for safety concepts; and (4) impact analysis and test methods.

Escape strategies for turboprop aircraft in microburst windshear

NASA Technical Reports Server (NTRS)

Bobbitt, Richard B.; Howard, Richard M.

1991-01-01

The dynamic reponse of a P-3 aircraft and a light twin-engine turboprop to a low-level microburst encounter is modeled. The response to the microburst is depicted for various escape maneuvers. Plots of altitude, velocity, and specific energy are shown for all cases. Takeoff escape strategies are discussed. The optimal escape procedure is found to be flying a constant value of pitch angle. Constant angle of attack maneuvers sometimes result in superior performance.

Infrared Signature Modeling and Analysis of Aircraft Plume

NASA Astrophysics Data System (ADS)

Rao, Arvind G.

2011-09-01

In recent years, the survivability of an aircraft has been put to task more than ever before. One of the main reasons is the increase in the usage of Infrared (IR) guided Anti-Aircraft Missiles, especially due to the availability of Man Portable Air Defence System (MANPADS) with some terrorist groups. Thus, aircraft IR signatures are gaining more importance as compared to their radar, visual, acoustic, or any other signatures. The exhaust plume ejected from the aircraft is one of the important sources of IR signature in military aircraft that use low bypass turbofan engines for propulsion. The focus of the present work is modelling of spectral IR radiation emission from the exhaust jet of a typical military aircraft and to evaluate the aircraft susceptibility in terms of the aircraft lock-on range due to its plume emission, for a simple case against a typical Surface to Air Missile (SAM). The IR signature due to the aircraft plume is examined in a holistic manner. A comprehensive methodology of computing IR signatures and its affect on aircraft lock-on range is elaborated. Commercial CFD software has been used to predict the plume thermo-physical properties and subsequently an in-house developed code was used for evaluating the IR radiation emitted by the plume. The LOWTRAN code has been used for modeling the atmospheric IR characteristics. The results obtained from these models are in reasonable agreement with some available experimental data. The analysis carried out in this paper succinctly brings out the intricacy of the radiation emitted by various gaseous species in the plume and the role of atmospheric IR transmissivity in dictating the plume IR signature as perceived by an IR guided SAM.

NASA Provides Coast-to-Coast Coverage of Aug. 21 Solar Eclipse (NASA Gulfstream III Aircraft, Off Oregon Coast)

NASA Image and Video Library

2017-08-21

On Monday, Aug. 21, NASA provided coast-to-coast coverage of the solar eclipse across America – featuring views of the phenomenon from unique vantage points, including from the ground, from aircraft, and from spacecraft including the ISS, during a live broadcast seen on NASA Television and the agency’s website. This is footage from NASA’s Gulfstream III research aircraft, flying off the Coast of Oregon.

Technical evaluation of the Aerospace Medical Panel Specialists Meeting on Escape Problems and Manoeuvres in Combat Aircraft

NASA Technical Reports Server (NTRS)

Jones, W. L.

1974-01-01

A technical evaluation of the papers presented at a conference on escape systems for helicopters and V/STOL aircraft was made. The subjects discussed include the following: (1) bioengineering aspects of spinal injury during ejection, (2) aerodynamic forces acting on crewman during escape, (3) operational practicality of fly away ejection seats, (4) helicopter survivability requirements, (5) ejection experience from V/STOL aircraft, and (6) research projects involving escape and retrieval systems.

The Langley-Newcomb brouhaha over the flying machine

NASA Astrophysics Data System (ADS)

Carter, W. E.; Carter, M. S.

One century after the Wright brothers proved it was possible to build a piloted heavier-than-air “flying machine,” several airlines will soon, perhaps as early as October 2005, begin to operate the largest passenger aircraft ever built, the Airbus A380. The A380 is nearly half again as large, in terms of passenger floor space, as the Boeing 747-400. It can be configured to hold as many as 840 passengers, and it has a takeoff weight of 550,000 kg, a maximum range of 15,000 km, and a cruising speed of Mach 0.85.The remarkable advances in aeronautics realized during the past century make it difficult to understand how anyone, let alone Simon Newcomb, one of the most prominent U.S. scientists at the turn of the twentieth century, could have opposed efforts by Samuel Pierpont Langley to build a piloted winged aircraft for the military. Newcomb argued that Langley was doomed to failure because the technology required to build such an aircraft was not then available, and he bemoaned the “waste” of scarce government funds toward the effort.

Preliminary simulation of an advanced, hingless rotor XV-15 tilt-rotor aircraft

NASA Technical Reports Server (NTRS)

Mcveigh, M. A.

1976-01-01

The feasibility of the tilt-rotor concept was verified through investigation of the performance, stability and handling qualities of the XV-15 tilt rotor. The rotors were replaced by advanced-technology fiberglass/composite hingless rotors of larger diameter, combined with an advanced integrated fly-by-wire control system. A parametric simulation model of the HRXV-15 was developed, model was used to define acceptable preliminary ranges of primary and secondary control schedules as functions of the flight parameters, to evaluate performance, flying qualities and structural loads, and to have a Boeing-Vertol pilot conduct a simulated flight test evaluation of the aircraft.

Small Aircraft Data Distribution System

NASA Technical Reports Server (NTRS)

Chazanoff, Seth L.; Dinardo, Steven J.

2012-01-01

The CARVE Small Aircraft Data Distribution System acquires the aircraft location and attitude data that is required by the various programs running on a distributed network. This system distributes the data it acquires to the data acquisition programs for inclusion in their data files. It uses UDP (User Datagram Protocol) to broadcast data over a LAN (Local Area Network) to any programs that might have a use for the data. The program is easily adaptable to acquire additional data and log that data to disk. The current version also drives displays using precision pitch and roll information to aid the pilot in maintaining a level-level attitude for radar/radiometer mapping beyond the degree available by flying visually or using a standard gyro-driven attitude indicator. The software is designed to acquire an array of data to help the mission manager make real-time decisions as to the effectiveness of the flight. This data is displayed for the mission manager and broadcast to the other experiments on the aircraft for inclusion in their data files. The program also drives real-time precision pitch and roll displays for the pilot and copilot to aid them in maintaining the desired attitude, when required, during data acquisition on mapping lines.

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

NASA Technical Reports Server (NTRS)

Gerdes, Ronald M.

1993-01-01

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

Detection and Analysis of High Ice Concentration Events and Supercooled Drizzle from IAGOS Commercial Aircraft

NASA Astrophysics Data System (ADS)

Gallagher, Martin; Baumgardner, Darrel; Lloyd, Gary; Beswick, Karl; Freer, Matt; Durant, Adam

2016-04-01

Hazardous encounters with high ice concentrations that lead to temperature and airspeed sensor measurement errors, as well as engine rollback and flameout, continue to pose serious problems for flight operations of commercial air carriers. Supercooled liquid droplets (SLD) are an additional hazard, especially for smaller commuter aircraft that do not have sufficient power to fly out of heavy icing conditions or heat to remove the ice. New regulations issued by the United States and European regulatory agencies are being implemented that will require aircraft below a certain weight class to carry sensors that will detect and warn of these types of icing conditions. Commercial aircraft do not currently carry standard sensors to detect the presence of ice crystals in high concentrations because they are typical found in sizes that are below the detection range of aircraft weather radar. Likewise, the sensors that are currently used to detect supercooled water do not respond well to drizzle-sized drops. Hence, there is a need for a sensor that can fill this measurement void. In addition, the forecast models that are used to predict regions of icing rely on pilot observations as the only means to validate the model products and currently there are no forecasts for the prevalence of high altitude ice crystals. Backscatter Cloud Probes (BCP) have been flying since 2011 under the IAGOS project on six Airbus commercial airliners operated by Lufthansa, Air France, China Air, Iberia and Cathay Pacific, and measure cloud droplets, ice crystals and aerosol particles larger than 5 μm. The BCP can detect these particles and measures an optical equivalent diameter (OED) but is not able to distinguish the type of particle, i.e. whether they are droplets, ice crystals, dust or ash. However, some qualification can be done based on measured temperature to discriminate between liquid water and ice. The next generation BCP (BCPD, Backscatter Cloud Probe with polarization detection) is

Airsickness and aircraft motion during short-haul flights.

PubMed

Turner, M; Griffin, M J; Holland, I

2000-12-01

There is little quantitative information that can be used to predict the incidence of airsickness from the motions experienced in military or civil aviation. This study examines the relationship between low-frequency aircraft motion and passenger sickness in short-haul turboprop flights within the United Kingdom. A questionnaire survey of 923 fare-paying passengers was conducted on 38 commercial airline flights. Concurrent measurements of aircraft motion were made on all journeys, yielding approximately 30 h of aircraft motion data. Overall, 0.5% of passengers reported vomiting, 8.4% reported nausea (range 0% to 34.8%) and 16.2% reported illness (range 0% to 47.8%) during flight. Positive correlations were found between the percentage of passengers who experienced nausea or felt ill and the magnitude of low-frequency lateral and vertical motion, although neither motion uniquely predicted airsickness. The incidence of motion sickness also varied with passenger age, gender, food consumption and activity during air travel. No differences in sickness were found between passengers located in different seating sections of the aircraft, or as a function of moderate levels of alcohol consumption. The passenger responses suggest that a useful prediction of airsickness can be obtained from magnitudes of low frequency aircraft motion. However, some variations in airsickness may also be explained by individual differences between passengers and their psychological perception of flying.

Recent progress in a classical biological control program for olive fruit fly in California

USDA-ARS?s Scientific Manuscript database

The olive fruit fly, Bactrocera oleae (Diptera: Tephritidae), causes severe damage to olive production worldwide. Control of olive fruit fly typically relies on pesticides, and under such conditions the impact of natural enemies is relatively low. About 15 years ago, the USDA-ARS European Biologic...

Flying the smoky skies: secondhand smoke exposure of flight attendants

PubMed Central

Repace, J

2004-01-01

Objective: To assess the contribution of secondhand smoke (SHS) to aircraft cabin air pollution and flight attendants' SHS exposure relative to the general population. Methods: Published air quality measurements, modelling studies, and dosimetry studies were reviewed, analysed, and generalised. Results: Flight attendants reported suffering greatly from SHS pollution on aircraft. Both government and airline sponsored studies concluded that SHS created an air pollution problem in aircraft cabins, while tobacco industry sponsored studies yielding similar data concluded that ventilation controlled SHS, and that SHS pollution levels were low. Between the time that non-smoking sections were established on US carriers in 1973, and the two hour US smoking ban in 1988, commercial aircraft ventilation rates had declined three times as fast as smoking prevalence. The aircraft cabin provided the least volume and lowest ventilation rate per smoker of any social venue, including stand up bars and smoking lounges, and afforded an abnormal respiratory environment. Personal monitors showed little difference in SHS exposures between flight attendants assigned to smoking sections and those assigned to non-smoking sections of aircraft cabins. Conclusions: In-flight air quality measurements in ~250 aircraft, generalised by models, indicate that when smoking was permitted aloft, 95% of the harmful respirable suspended particle (RSP) air pollution in the smoking sections and 85% of that in the non-smoking sections of aircraft cabins was caused by SHS. Typical levels of SHS-RSP on aircraft violated current (PM2.5) federal air quality standards ~threefold for flight attendants, and exceeded SHS irritation thresholds by 10 to 100 times. From cotinine dosimetry, SHS exposure of typical flight attendants in aircraft cabins is estimated to have been >6-fold that of the average US worker and ~14-fold that of the average person. Thus, ventilation systems massively failed to control SHS air

Flying the smoky skies: secondhand smoke exposure of flight attendants.

PubMed

Repace, J

2004-03-01

To assess the contribution of secondhand smoke (SHS) to aircraft cabin air pollution and flight attendants' SHS exposure relative to the general population. Published air quality measurements, modelling studies, and dosimetry studies were reviewed, analysed, and generalised. Flight attendants reported suffering greatly from SHS pollution on aircraft. Both government and airline sponsored studies concluded that SHS created an air pollution problem in aircraft cabins, while tobacco industry sponsored studies yielding similar data concluded that ventilation controlled SHS, and that SHS pollution levels were low. Between the time that non-smoking sections were established on US carriers in 1973, and the two hour US smoking ban in 1988, commercial aircraft ventilation rates had declined three times as fast as smoking prevalence. The aircraft cabin provided the least volume and lowest ventilation rate per smoker of any social venue, including stand up bars and smoking lounges, and afforded an abnormal respiratory environment. Personal monitors showed little difference in SHS exposures between flight attendants assigned to smoking sections and those assigned to non-smoking sections of aircraft cabins. In-flight air quality measurements in approximately 250 aircraft, generalised by models, indicate that when smoking was permitted aloft, 95% of the harmful respirable suspended particle (RSP) air pollution in the smoking sections and 85% of that in the non-smoking sections of aircraft cabins was caused by SHS. Typical levels of SHS-RSP on aircraft violated current (PM(2.5)) federal air quality standards approximately threefold for flight attendants, and exceeded SHS irritation thresholds by 10 to 100 times. From cotinine dosimetry, SHS exposure of typical flight attendants in aircraft cabins is estimated to have been >6-fold that of the average US worker and approximately 14-fold that of the average person. Thus, ventilation systems massively failed to control SHS air

14 CFR 91.1089 - Qualifications: Check pilots (aircraft) and check pilots (simulator).

Code of Federal Regulations, 2013 CFR

2013-01-01

... simulator, or in a flight training device for a particular type aircraft. (2) A check pilot (simulator) is a person who is qualified to conduct flight checks, but only in a flight simulator, in a flight training... (simulator) must accomplish the following— (1) Fly at least two flight segments as a required crewmember for...

14 CFR 91.1089 - Qualifications: Check pilots (aircraft) and check pilots (simulator).

Code of Federal Regulations, 2014 CFR

2014-01-01

... simulator, or in a flight training device for a particular type aircraft. (2) A check pilot (simulator) is a person who is qualified to conduct flight checks, but only in a flight simulator, in a flight training... (simulator) must accomplish the following— (1) Fly at least two flight segments as a required crewmember for...

14 CFR 91.1089 - Qualifications: Check pilots (aircraft) and check pilots (simulator).

Code of Federal Regulations, 2012 CFR

2012-01-01

... simulator, or in a flight training device for a particular type aircraft. (2) A check pilot (simulator) is a person who is qualified to conduct flight checks, but only in a flight simulator, in a flight training... (simulator) must accomplish the following— (1) Fly at least two flight segments as a required crewmember for...

Flying at No Mechanical Energy Cost: Disclosing the Secret of Wandering Albatrosses

PubMed Central

Sachs, Gottfried; Traugott, Johannes; Nesterova, Anna P.; Dell'Omo, Giacomo; Kümmeth, Franz; Heidrich, Wolfgang

2012-01-01

Albatrosses do something that no other birds are able to do: fly thousands of kilometres at no mechanical cost. This is possible because they use dynamic soaring, a flight mode that enables them to gain the energy required for flying from wind. Until now, the physical mechanisms of the energy gain in terms of the energy transfer from the wind to the bird were mostly unknown. Here we show that the energy gain is achieved by a dynamic flight manoeuvre consisting of a continually repeated up-down curve with optimal adjustment to the wind. We determined the energy obtained from the wind by analysing the measured trajectories of free flying birds using a new GPS-signal tracking method yielding a high precision. Our results reveal an evolutionary adaptation to an extreme environment, and may support recent biologically inspired research on robotic aircraft that might utilize albatrosses' flight technique for engineless propulsion. PMID:22957014

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

NASA Technical Reports Server (NTRS)

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

2010-01-01

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

Air Force Air Refueling: The KC-X Aircraft Acquisition Program

DTIC Science & Technology

2008-08-04

7 Boom vs . Probe and Drogue Air Refueling . . . . . . . . . . . . . . . . . . . . . . 7 Capacity vs ...consideration must be given to a few key attributes. For example, a tanker aircraft’s method of dispensing fuel – flying boom vs . probe and drogue – is a key...flight, which can add considerable flexibility to certain air operations. Boom vs . Probe and Drogue Air Refueling.32 Aircraft can be equipped to be

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

NASA Technical Reports Server (NTRS)

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

1959-01-01

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

Control Reallocation Strategies for Damage Adaptation in Transport Class Aircraft

NASA Technical Reports Server (NTRS)

Gundy-Burlet, Karen; Krishnakumar, K.; Limes, Greg; Bryant, Don

2003-01-01

This paper examines the feasibility, potential benefits and implementation issues associated with retrofitting a neural-adaptive flight control system (NFCS) to existing transport aircraft, including both cable/hydraulic and fly-by-wire configurations. NFCS uses a neural network based direct adaptive control approach for applying alternate sources of control authority in the presence of damage or failures in order to achieve desired flight control performance. Neural networks are used to provide consistent handling qualities across flight conditions, adapt to changes in aircraft dynamics and to make the controller easy to apply when implemented on different aircraft. Full-motion piloted simulation studies were performed on two different transport models: the Boeing 747-400 and the Boeing C-17. Subjects included NASA, Air Force and commercial airline pilots. Results demonstrate the potential for improving handing qualities and significantly increased survivability rates under various simulated failure conditions.

Passenger aircraft cabin air quality: trends, effects, societal costs, proposals.

PubMed

Hocking, M B

2000-08-01

As aircraft operators have sought to substantially reduce propulsion fuel cost by flying at higher altitudes, the energy cost of providing adequate outside air for ventilation has increased. This has lead to a significant decrease in the amount of outside air provided to the passenger cabin, partly compensated for by recirculation of filtered cabin air. The purpose of this review paper is to assemble the available measured air quality data and some calculated estimates of the air quality for aircraft passenger cabins to highlight the trend of the last 25 years. The influence of filter efficiencies on air quality, and a few medically documented and anecdotal cases of illness transmission aboard aircraft are discussed. Cost information has been collected from the perspective of both the airlines and passengers. Suggestions for air quality improvement are given which should help to result in a net, multistakeholder savings and improved passenger comfort.

Analysis of aircraft performance during lateral maneuvering for microburst avoidance

NASA Technical Reports Server (NTRS)

Avila De Melo, Denise; Hansman, R. John, Jr.

1990-01-01

Aircraft response to a severe and a moderate three-dimensional microburst model using nonlinear numerical simulations of a Boeing 737-100 is studied. The relative performance loss is compared for microburst escape procedures with and without lateral maneuvering. The results show that the hazards caused by the penetration of a microburst in the landing phase are attenuated if lateral escape maneuvers are applied in order to turn the aircraft away from the microburst core rather than flying straight through. If the lateral escape maneuver is initiated close to the microburst core, high bank angles tend to deteriorate aircraft performance. Lateral maneuvering is also found to reduce the advanced warning required to escape from microburst hazards but requires that information of the existence and location of the microburst is available (i.e., remote detection) in order to avoid an incorrect turn toward the microburst core.

CID Aircraft pre-impact lakebed skid

NASA Technical Reports Server (NTRS)

1984-01-01

The B-720 is seen viewed moments after impact and just before hitting the wing openers. 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

Interaction of feel system and flight control system dynamics on lateral flying qualities

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Powers, Bruce G.; Shafer, Mary F.

1988-01-01

An investigation of feel system and flight control system dynamics on lateral flying qualities was conducted using the variable stability USAF NT-33 aircraft. Experimental variations in feel system natural frequency, force-deflection gradient, control system command architecture type, flight control system filter frequency, and control system delay were made. The experiment data include pilot ratings using the Cooper-Harper (1969) rating scale, pilot comments, and tracking performance statistic. Three test pilots served as evaluators. The data indicate that as the feel system natural frequency is reduced lateral flying qualities degrade. At the slowest feel system frequency, the closed-loop response becomes nonlinear with a 'bobweight' effect apparent in the feel system. Feel system influences were essentially independent of the control system architecture. The flying qualities influence due to the feel system was different than when the identical dynamic systenm was used as a flight control system element.

W5 - If Pigs Could Fly

NASA Astrophysics Data System (ADS)

Cannon, Trina

2012-10-01

Centripetal force seems to be a challenge for students and we are typically using stoppers, string, tubes and slotted masses (that always crash to the floor). But if we use a toy that reminds them of an amusement park ride, we can get the message across and have some fun. Come and see if pigs can fly!

Beware of agents when flying aircraft: Basic principles behind a generic methodology for the evaluation and certification of advanced aviation systems

NASA Technical Reports Server (NTRS)

Javaux, Denis; Masson, Michel; Dekeyser, Veronique

1994-01-01

There is currently a growing interest in the aeronautical community to assess the effects of the increasing levels of automation on pilots' performance and overall safety. The first effect of automation is the change in the nature of the pilot's role on the flight deck. Pilots have become supervisors who monitor aircraft systems in usual situations and intervene only when unanticipated events occur. Instead of 'hand flying' the airplane, pilots contribute to the control of aircraft by acting as mediators, instructions given to the automation. By eliminating the need for manually controlling normal situations, such a role division has reduced the opportunities for the pilot to acquire experience and skills necessary to safely cope with abnormal events. Difficulties in assessing the state and behavior of automation arise mainly from four factors: (1) the complexity of current systems and consequence mode-related problems; (2) the intrinsic autonomy of automation which is able to fire mode transitions without explicit commands from the pilots; (3) the bad quality of feed-back from the control systems displays and interfaces to the pilots; and (4) the fact that the automation currently has no explicit representation of the current pilots' intentions and strategy. Assuming certification has among its major goals to guarantee the passengers' and pilots' safety and the airplane integrity under normal and abnormal operational conditions, the authors suggest it would be particularly fruitful to come up with a conceptual reference system providing the certification authorities both with a theoretical framework and a list of principles usable for assessing the quality of the equipment and designs under examination. This is precisely the scope of this paper. However, the authors recognize that the conceptual presented is still under development and would thus be best considered as a source of reflection for the design, evaluation and certification processes of advanced

First-Order Altitude Effects on the Cruise Efficiency of Subsonic Transport Aircraft

NASA Technical Reports Server (NTRS)

Guynn, Mark D.

2011-01-01

Aircraft fuel efficiency is a function of many different parameters, including characteristics of the engines, characteristics of the airframe, and the conditions under which the aircraft is operated. For a given vehicle, the airframe and engine characteristics are for the most part fixed quantities and efficiency is primarily a function of operational conditions. One important influence on cruise efficiency is cruise altitude. Various future scenarios have been postulated for cruise altitude, from the freedom to fly at optimum altitudes to altitude restrictions imposed for environmental reasons. This report provides background on the fundamental relationships determining aircraft cruise efficiency and examines the sensitivity of efficiency to cruise altitude. Analytical models of two current aircraft designs are used to derive quantitative results. Efficiency penalties are found to be generally less than 1% when within roughly 2000 ft of the optimum cruise altitude. Even the restrictive scenario of constant altitude cruise is found to result in a modest fuel consumption penalty if the fixed altitude is in an appropriate range.

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

NASA Technical Reports Server (NTRS)

Franklin, James A.

1993-01-01

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

Loss-of-Control-Inhibitor Systems for Aircraft

NASA Technical Reports Server (NTRS)

AHarrah, Ralph C.

2007-01-01

Systems to provide improved tactile feedback to aircraft pilots are being developed to help the pilots maintain harmony between their control actions and the positions of aircraft control surfaces, thereby helping to prevent loss of control. A system of this type, denoted a loss-of-control-inhibitor system (LOCIS) can be implemented as a relatively simple addition to almost any pre-existing flight-control system. The LOCIS concept offers at least a partial solution to the problem of (1) keeping a pilot aware of the state of the control system and the aircraft and (2) maintaining sufficient control under conditions that, as described below, have been known to lead to loss of control. Current commercial aircraft exhibit uneven responses of primary flight-control surfaces to aggressive pilot control commands, leading to deterioration of pilots ability to control their aircraft. In severe cases, this phenomenon can result in loss of control and consequent loss of aircraft. For an older aircraft equipped with a purely mechanical control system, the loss of harmony between a pilot s command action and the control- surface response can be attributed to compliance in the control system (caused, for example, by stretching of control cables, flexing of push rods, or servo-valve distortion). In a newer aircraft equipped with a fly-by-wire control system, the major contributions to loss of harmony between the pilot and the control surfaces are delays attributable to computer cycle time, control shaping, filtering, aliasing, servo-valve distortion, and actuator rate limiting. In addition, a fly-by-wire control system provides no tactile feedback that would enable the pilot to sense such features of the control state as surface flutter, surface jam, position limiting, actuator rate limiting, and control limiting imposed by the aircraft operational envelope. Hence, for example, when a pilot is involved in aggressive closed-loop maneuvering, as when encountering a wake

Supercharger Research at the Aircraft Engine Research Laboratory

NASA Image and Video Library

1944-01-21

A researcher in the Supercharger Research Division at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory measures the blade thickness on a supercharger. Superchargers were developed at General Electric used to supply additional air to reciprocating engines. The extra air resulted in increased the engine’s performance, particularly at higher altitudes. The Aircraft Engine Research Laboratory had an entire division dedicated to superchargers during World War II. General Electric developed the supercharger in response to a 1917 request from the NACA to develop a device to enhance high-altitude flying. The supercharger pushed larger volumes of air into the engine manifold. The extra oxygen allowed the engine to operate at its optimal sea-level rating even when at high altitudes. Thus, the aircraft could maintain its climb rate, maneuverability and speed as it rose higher into the sky. NACA work on the supercharger ceased after World War II due to the arrival of the turbojet engine. The Supercharger Research Division was disbanded in October 1945 and reconstituted as the Compressor and Turbine Division.

A comparison of Freon- and water-based insecticidal aerosols for aircraft disinsection*

PubMed Central

Sullivan, W. N.; Cawley, B. M.; Schechter, M. S.; Hayes, D. K.; Staker, Kathleen; Pal, R.

1978-01-01

In Miami, USA, passenger compartments of wide-bodied jet aircraft were disinsected at ”blocks away” or while parked. The application of 2% Freon- and water-based formulations of (+)-phenothrin at about 35 g/100 m3 was highly effective against mosquitos and flies in all instances. More basic research is needed on water-based aerosols. PMID:307441

ER-2: Flying Laboratory for Earth Science Studies

NASA Technical Reports Server (NTRS)

Navarro, Robert

2007-01-01

The National Aeronautics and Space Administration (NASA) Dryden Flight Research Center (DFRC), (Edwards, California, USA) has two Lockheed Martin Corporation (Bethesda, Maryland) Earth Research-2 (ER-2) aircraft that serve as high-altitude and long-range flying laboratories. The ER-2 has been 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 ER-2 aircraft provides experimenters with a wide array of payload accommodation areas with suitable environment control with required electrical and mechanical interfaces. Missions may be flown out of DFRC or from remote bases worldwide. The NASA ER-2 is utilized by a variety of customers, including U.S. Government agencies, civilian organizations, universities, and state governments. The combination of the ER-2 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.

X-wing fly-by-wire vehicle management system

NASA Technical Reports Server (NTRS)

Fischer, Jr., William C. (Inventor)

1990-01-01

A complete, computer based, vehicle management system (VMS) for X-Wing aircraft using digital fly-by-wire technology controlling many subsystems and providing functions beyond the classical aircraft flight control system. The vehicle management system receives input signals from a multiplicity of sensors and provides commands to a large number of actuators controlling many subsystems. The VMS includes--segregating flight critical and mission critical factors and providing a greater level of back-up or redundancy for the former; centralizing the computation of functions utilized by several subsystems (e.g. air data, rotor speed, etc.); integrating the control of the flight control functions, the compressor control, the rotor conversion control, vibration alleviation by higher harmonic control, engine power anticipation and self-test, all in the same flight control computer (FCC) hardware units. The VMS uses equivalent redundancy techniques to attain quadruple equivalency levels; includes alternate modes of operation and recovery means to back-up any functions which fail; and uses back-up control software for software redundancy.

Effect of power system technology and mission requirements on high altitude long endurance aircraft

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.

1994-01-01

An analysis was performed to determine how various power system components and mission requirements affect the sizing of a solar powered long endurance aircraft. The aircraft power system consists of photovoltaic cells and a regenerative fuel cell. Various characteristics of these components, such as PV cell type, PV cell mass, PV cell efficiency, fuel cell efficiency, and fuel cell specific mass, were varied to determine what effect they had on the aircraft sizing for a given mission. Mission parameters, such as time of year, flight altitude, flight latitude, and payload mass and power, were also altered to determine how mission constraints affect the aircraft sizing. An aircraft analysis method which determines the aircraft configuration, aspect ratio, wing area, and total mass, for maximum endurance or minimum required power based on the stated power system and mission parameters is presented. The results indicate that, for the power system, the greatest benefit can be gained by increasing the fuel cell specific energy. Mission requirements also substantially affect the aircraft size. By limiting the time of year the aircraft is required to fly at high northern or southern latitudes, a significant reduction in aircraft size or increase in payload capacity can be achieved.

A mathematic model that describes modes of MdSGHV transmission within house fly populations

USDA-ARS?s Scientific Manuscript database

In this paper it is proposed that one potential component by which the Musca domestica salivary gland hypertrophy virus (MdSGHV) infects individual flies is through cuticular damage. Breaks in the cuticle allow entry of the virus into the hemocoel causing the infection. Male flies typically have a h...

NASA Dryden Flight Research Center: We Fly What Others Only Imagine

NASA Technical Reports Server (NTRS)

Ennix-Sandhu, Kimberly

2006-01-01

A powerpoint presentation of NASA Dryden's historical and future flight programs is shown. The contents include: 1) Getting To Know NASA; 2) Our Namesake; 3) To Fly What Others Only Imagine; 4) Dryden's Mission: Advancing Technology and Science Through Flight; 5) X-1 The First of the Rocket-Powered Research Aircraft; 6) X-1 Landing; 7) Lunar Landing Research Vehicle (LLRV) Liftoff and Landing; 8) Linear Aerospike SR-71 Experiment (LASRE) Ground Test; 9) M2-F1 (The Flying Bathtub); 10) M2-F2 Drop Test; 11) Enterprise Space Shuttle Prototype; 12) Space Shuttle Columbia STS-1; 13) STS-114 Landing-August 2005; 14) Crew Exploration Vehicle (CEV); 15) What You Can Do To Succeed!; and 16) NASA Dryden Flight Research Center: This is What We Do!

Judgments of aircraft noise in a traffic noise background

NASA Technical Reports Server (NTRS)

Powell, C. A.; Rice, C. G.

1975-01-01

An investigation was conducted to determine subjective response to aircraft noise in different road traffic backgrounds. In addition, two laboratory techniques for presenting the aircraft noise with the background noise were evaluated. For one technique, the background noise was continuous over an entire test session; for the other, the background noise level was changed with each aircraft noise during a session. Subjective response to aircraft noise was found to decrease with increasing background noise level, for a range of typical indoor noise levels. Subjective response was found to be highly correlated with the Noise Pollution Level (NPL) measurement scale.

Flight-Test Validation and Flying Qualities Evaluation of a Rotorcraft UAV Flight Control System

NASA Technical Reports Server (NTRS)

Mettler, Bernard; Tuschler, Mark B.; Kanade, Takeo

2000-01-01

This paper presents a process of design and flight-test validation and flying qualities evaluation of a flight control system for a rotorcraft-based unmanned aerial vehicle (RUAV). The keystone of this process is an accurate flight-dynamic model of the aircraft, derived by using system identification modeling. The model captures the most relevant dynamic features of our unmanned rotorcraft, and explicitly accounts for the presence of a stabilizer bar. Using the identified model we were able to determine the performance margins of our original control system and identify limiting factors. The performance limitations were addressed and the attitude control system was 0ptimize.d for different three performance levels: slow, medium, fast. The optimized control laws will be implemented in our RUAV. We will first determine the validity of our control design approach by flight test validating our optimized controllers. Subsequently, we will fly a series of maneuvers with the three optimized controllers to determine the level of flying qualities that can be attained. The outcome enable us to draw important conclusions on the flying qualities requirements for small-scale RUAVs.

A Simple Two Aircraft Conflict Resolution Algorithm

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.

2006-01-01

Conflict detection and resolution methods are crucial for distributed air-ground traffic management in which the crew in, the cockpit, dispatchers in operation control centers sad and traffic controllers in the ground-based air traffic management facilities share information and participate in the traffic flow and traffic control functions. This paper describes a conflict detection, and a conflict resolution method. The conflict detection method predicts the minimum separation and the time-to-go to the closest point of approach by assuming that both the aircraft will continue to fly at their current speeds along their current headings. The conflict resolution method described here is motivated by the proportional navigation algorithm, which is often used for missile guidance during the terminal phase. It generates speed and heading commands to rotate the line-of-sight either clockwise or counter-clockwise for conflict resolution. Once the aircraft achieve a positive range-rate and no further conflict is predicted, the algorithm generates heading commands to turn back the aircraft to their nominal trajectories. The speed commands are set to the optimal pre-resolution speeds. Six numerical examples are presented to demonstrate the conflict detection, and the conflict resolution methods.

Baseline monitoring using aircraft laser ranging. [spaceborne laser simulation and aircraft laser tracking

NASA Technical Reports Server (NTRS)

Krabill, W. B.; Hoge, F. E.; Martin, C. F.

1982-01-01

The use of aircraft laser ranging for the determination of baselines between ground based retroreflectors was investigated via simulations and with tests at Wallops Flight Center using the Airborne Oceanographic Lidar (AOL) on the Wallops C-54 aircraft ranging to a reflector array deployed around one of the Wallops runways. The aircraft altitude and reflector spacing were chosen on the basis of scaled down modeling of spacecraft tracking from 1000 km of reflectors separated by some 52 km, or of high altitude (10 km) aircraft tracking of reflectors separated by some 500 m. Aircraft altitudes flown for different passes across the runway reflector array varied from 800 m to 1350 m, with 32 reflectors deployed over an approximtely 300 m x 500 m ground pattern. The AOL transmitted 400 pulses/sec with a scan rate of 5/sec in a near circular pattern, so that the majority of the pulses were reflected by the runway surface or its environs rather than by retroreflectors. The return pulse characteristics clearly showed the high reflectivity of portions of the runway, with several returns indistinguishable in amplitude from reflector returns. For each pass across the reflector field, typically six to ten reflector hits were identified, consistent with that predicted by simulations and the observed transmitted elliptical pulse size.

System design requirements for advanced rotary-wing agricultural aircraft

NASA Technical Reports Server (NTRS)

Lemont, H. E.

1979-01-01

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.

Caater: Arat - Fokker 27, aircraft facility

NASA Astrophysics Data System (ADS)

Penazzi, G.; Joussaume, S.

2003-04-01

ARAT (Avion de Recherche Atmosphérique et de Télédétection), is owned and operated by IGN (Institut Géographique National) and managed by INSU, an institute of CNRS (Centre National de la Recherche Scientifique). ARAT is a versatile flying laboratory offering several scientific configurations: basic meteorological instrumentation, turbulent flux equipment, radiation measurement (Visible, Red, IR, UV, J(NO_2), radiance, ground temperature), microphysics sensors, in-situ and remote sensing chemistry instruments (NO-NO_2-NOy and PAN, Water Vapour and Ozone Lidars), Aerosol Lidar, Earth Observation Instrumentation (Visible, Microwave, POLDER), etc. Access to ARAT was offered through the EC-funded IHP-ARI contract, under a co-ordinated aircraft project (with MRF, U.K.; DLR, Germany and Meteo France) called CAATER (Co-ordinated Access to Aircraft for Transnational Environmental Research). Since 2000 access to ARAT has been offered to 6 research groups from different EU Member States for about 10 flight hours each. This project is a follow-on to STAAARTE (1996-2000), which gave access to ARAT to 14 user groups for about 8 flight hours per group. A new project, with new aircraft, within the frame of an Integrated Infrastructure Initiative of the Sixth Framework Programme is currently in preparation.

Dryden B-52 Launch Aircraft on Dryden Ramp

NASA Technical Reports Server (NTRS)

1996-01-01

NASA's venerable B-52 mothership sits on the ramp in front of the Dryden Flight Research Center, Edwards, California. Over the course of more than 40 years, the B-52 launched numerous experimental aircraft, ranging from the X-15 to the X-38, and was also used as a flying testbed for a variety of other research projects. 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

Measuring physiological stress in Australian flying-fox populations.

PubMed

McMichael, Lee A; Edson, Daniel; Field, Hume

2014-09-01

Flying-foxes (pteropid bats) are the natural host of Hendra virus, a recently emerged zoonotic virus responsible for mortality or morbidity in horses and humans in Australia since 1994. Previous studies have suggested physiological and ecological risk factors for infection in flying-foxes, including physiological stress. However, little work has been done measuring and interpreting stress hormones in flying-foxes. Over a 12-month period, we collected pooled urine samples from underneath roosting flying-foxes, and urine and blood samples from captured individuals. Urine and plasma samples were assayed for cortisol using a commercially available enzyme immunoassay. We demonstrated a typical post-capture stress response in flying-foxes, established urine specific gravity as an attractive alternative to creatinine to correct urine concentration, and established population-level urinary cortisol ranges (and geometric means) for the four Australian species: Pteropus alecto 0.5-305.1 ng/mL (20.1 ng/mL); Pteropus conspicillatus 0.3-370.9 ng/mL (18.9 ng/mL); Pteropus poliocephalus 0.3-311.3 ng/mL (10.1 ng/mL); Pteropus scapulatus 5.2-205.4 ng/mL (40.7 ng/mL). Geometric means differed significantly except for P. alecto and P. conspicillatus. Our approach is methodologically robust, and has application both as a research or clinical tool for flying-foxes, and for other free-living colonial wildlife species.

In-flight acoustic testing techniques using the YO-3A Acoustic Research Aircraft

NASA Technical Reports Server (NTRS)

Cross, J. L.; Watts, M. E.

1984-01-01

This report discusses the flight testing techniques and equipment employed during air-to-air acoustic testing of helicopters at Ames Research Center. The in flight measurement technique used enables acoustic data to be obtained without the limitations of anechoic chambers or the multitude of variables encountered in ground based flyover testing. The air-to-air testing is made possible by the NASA YO-3A Acoustic Research Aircraft. This "Quiet Aircraft' is an acoustically instrumented version of a quiet observation aircraft manufactured for the military. To date, tests with the following aircraft have been conducted: YO-3A background noise; Hughes 500D; Hughes AH-64; Bell AH-1S; Bell AH-1G. Several system upgrades are being designed and implemented to improve the quality of data. This report will discuss not only the equipment involved and aircraft tested, but also the techniques used in these tests. In particular, formation flying position locations, and the test matrices will be discussed. Examples of data taken will also be presented.

In-flight acoustic testing techniques using the YO-3A acoustic research aircraft

NASA Technical Reports Server (NTRS)

Cross, J. L.; Watts, M. E.

1983-01-01

This report discusses the flight testing techniques and equipment employed during air-to-air acoustic testing of helicopters at Ames Research Center. The in-flight measurement technique used enables acoustic data to be obtained without the limitations of anechoic chambers or the multitude of variables encountered in ground based flyover testing. The air-to-air testing is made possible by the NASA YO-3A Acoustic Research Aircraft. This 'Quiet Aircraft' is an acoustically instrumented version of a quiet observation aircraft manufactured for the military. To date, tests with the following aircraft have been conducted: YO-3A background noise; Hughes 500D; Hughes AH-64; Bell AH-1S; Bell AH-1G. Several system upgrades are being designed and implemented to improve the quality of data. This report will discuss not only the equipment involved and aircraft tested, but also the techniques used in these tests. In particular, formation flying, position locations, and the test matrices will be discussed. Examples of data taken will also be presented.

Aircraft control system

NASA Technical Reports Server (NTRS)

Kendall, Greg T. (Inventor); Lisoski, Derek L. (Inventor)

2007-01-01

A solar rechargeable, long-duration, span-loaded flying wing, having no fuselage or rudder. 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, pitch and yaw. The wing is configured to deform under flight loads to position the propellers such that the control can be achieved. Each of five segments of the wing has one or more motors and photovoltaic arrays, and produces its own lift independent of the other segments, 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.

A Collection of Nonlinear Aircraft Simulations in MATLAB

NASA Technical Reports Server (NTRS)

Garza, Frederico R.; Morelli, Eugene A.

2003-01-01

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

Proceedings of the F-8 Digital Fly-By-Wire and Supercritical Wing First Flight's 20th Anniversary Celebration. Volume 1

NASA Technical Reports Server (NTRS)

Hodge, Kenneth E. (Compiler)

1996-01-01

A technical symposium, aircraft display dedication, and pilots' panel discussion were held on May 27, 1992, to commemorate the 20th anniversary of the first flights of the F-8 Digital Fly-By-Wire (DFBW) and Supercrit- ical Wing (SCW) research aircraft. The symposium featured technical presentations by former key government and industry participants in the advocacy, design, aircraft modification, and flight research program activities. The DFBW and SCW technical contributions are cited. A dedication ceremony marked permanent display of both program aircraft. The panel discussion participants included eight of the eighteen research and test pilots who flew these experimental aircraft. Pilots' remarks include descriptions of their most memorable flight experiences The report also includes a survey of the Gulf Air War, and an after-dinner presentation by noted aerospace author and historian Dr. Richard Hallion.

Tree Canopy Light Interception Estimates in Almond and a Walnut Orchards Using Ground, Low Flying Aircraft, and Satellite Based Methods to Improve Irrigation Scheduling Programs

NASA Technical Reports Server (NTRS)

Rosecrance, Richard C.; Johnson, Lee; Soderstrom, Dominic

2016-01-01

Canopy light interception is a main driver of water use and crop yield in almond and walnut production. Fractional green canopy cover (Fc) is a good indicator of light interception and can be estimated remotely from satellite using the normalized difference vegetation index (NDVI) data. Satellite-based Fc estimates could be used to inform crop evapotranspiration models, and hence support improvements in irrigation evaluation and management capabilities. Satellite estimates of Fc in almond and walnut orchards, however, need to be verified before incorporating them into irrigation scheduling or other crop water management programs. In this study, Landsat-based NDVI and Fc from NASA's Satellite Irrigation Management Support (SIMS) were compared with four estimates of canopy cover: 1. light bar measurement, 2. in-situ and image-based dimensional tree-crown analyses, 3. high-resolution NDVI data from low flying aircraft, and 4. orchard photos obtained via Google Earth and processed by an Image J thresholding routine. Correlations between the various estimates are discussed.

Tree canopy light interception estimates in almond and a walnut orchards using ground, low flying aircraft, and satellite based methods to improve irrigation scheduling programs.

NASA Astrophysics Data System (ADS)

Rosecrance, R. C.; Johnson, L.; Soderstrom, D.

2016-12-01

Canopy light interception is a main driver of water use and crop yield in almond and walnut production. Fractional green canopy cover (Fc) is a good indicator of light interception and can be estimated remotely from satellite using the normalized difference vegetation index (NDVI) data. Satellite-based Fc estimates could be used to inform crop evapotranspiration models, and hence support improvements in irrigation evaluation and management capabilities. Satellite estimates of Fc in almond and walnut orchards, however, need to be verified before incorporating them into irrigation scheduling or other crop water management programs. In this study, Landsat-based NDVI and Fc from NASA's Satellite Irrigation Management Support (SIMS) were compared with four estimates of canopy cover: 1. light bar measurement, 2. in-situ and image-based dimensional tree-crown analyses, 3. high-resolution NDVI data from low flying aircraft, and 4. orchard photos obtained via Google Earth and processed by an Image J thresholding routine. Correlations between the various estimates are discussed.

Flight-Deck Strategies and Outcomes When Flying Schedule-Matching Descents

NASA Technical Reports Server (NTRS)

Kaneshige, John T.; Sharma, Shivanjli; Martin Lynne; Lozito, Sandra; Dulchinos, Victoria

2013-01-01

Recent studies at NASA Ames Research Center have investigated the development and use of ground-based (air traffic controller) tools to manage and schedule air traffic in future terminal airspace. An exploratory study was undertaken to investigate the impacts that such tools (and concepts) could have on the flight-deck. Ten Boeing 747-400 crews flew eight optimized profile descents in the Los Angeles terminal airspace, while receiving scripted current day and futuristic speed clearances, to ascertain their ability to fly schedulematching descents without prior training. Although the study was exploratory in nature, four variables were manipulated: route constraints, winds, speed changes, and clearance phraseology. Despite flying the same scenarios with the same events and timing, there were significant differences in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The focus of this paper is the examination of the crews' aircraft management strategies and outcomes. This includes potentially problematic human-automation interaction issues that may negatively impact arrival times, speed and altitude constraint compliance, and energy management efficiency.

Automated Surveillance of Fruit Flies

PubMed Central

Potamitis, Ilyas; Rigakis, Iraklis; Tatlas, Nicolaos-Alexandros

2017-01-01

Insects of the Diptera order of the Tephritidae family cause costly, annual crop losses worldwide. Monitoring traps are important components of integrated pest management programs used against fruit flies. Here we report the modification of typical, low-cost plastic traps for fruit flies by adding the necessary optoelectronic sensors to monitor the entrance of the trap in order to detect, time-stamp, GPS tag, and identify the species of incoming insects from the optoacoustic spectrum analysis of their wingbeat. We propose that the incorporation of automated streaming of insect counts, environmental parameters and GPS coordinates into informative visualization of collective behavior will finally enable better decision making across spatial and temporal scales, as well as administrative levels. The device presented is at product level of maturity as it has solved many pending issues presented in a previously reported study. PMID:28075346

Flow Visualization of Aircraft in Flight by Means of Background Oriented Schlieren Using Celestial Objects

NASA Technical Reports Server (NTRS)

Hill, Michael A.; Haering, Edward A., Jr.

2017-01-01

The Background Oriented Schlieren using Celestial Objects series of flights was undertaken in the spring of 2016 at National Aeronautics and Space Administration Armstrong Flight Research Center to further develop and improve a flow visualization technique which can be performed from the ground upon flying aircraft. Improved hardware and imaging techniques from previous schlieren tests were investigated. A United States Air Force T-38C and NASA B200 King Air aircraft were imaged eclipsing the sun at ranges varying from 2 to 6 nautical miles, at subsonic and supersonic speeds.

Atmospheric effects of stratospheric aircraft: An evaluation of NASA's interim assessment

NASA Technical Reports Server (NTRS)

1994-01-01

The advent of high-speed civil transport aircraft (HSCT's) some 25 years ago generated considerable concern about potential impacts on the stratosphere. With interest in such aircraft again increasing, NASA initiated an assessment of the potential stratospheric impacts of a substantial increase in the use of HSCT's. This assessment was intended to examine, from the standpoint of present scientific understanding, the potential atmospheric impacts of a fleet of high-speed civil transports flying supersonically in the lower stratosphere. The program was initiated in 1991, and the bulk of its research is scheduled to be completed in 1995. In early 1993 NASA asked the National Research Council to review its efforts. This report documents its findings and recommendations.

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

NASA Technical Reports Server (NTRS)

Franklin, James A.

1993-01-01

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

Millimeter-Wave Localizers for Aircraft-to-Aircraft Approach Navigation

NASA Technical Reports Server (NTRS)

Tang, Adrian J.

2013-01-01

Aerial refueling technology for both manned and unmanned aircraft is critical for operations where extended aircraft flight time is required. Existing refueling assets are typically manned aircraft, which couple to a second aircraft through the use of a refueling boom. Alignment and mating of the two aircraft continues to rely on human control with use of high-resolution cameras. With the recent advances in unmanned aircraft, it would be highly advantageous to remove/reduce human control from the refueling process, simplifying the amount of remote mission management and enabling new operational scenarios. Existing aerial refueling uses a camera, making it non-autonomous and prone to human error. Existing commercial localizer technology has proven robust and reliable, but not suited for aircraft-to-aircraft approaches like in aerial refueling scenarios since the resolution is too coarse (approximately one meter). A localizer approach system for aircraft-to-aircraft docking can be constructed using the same modulation with a millimeterwave carrier to provide high resolution. One technology used to remotely align commercial aircraft on approach to a runway are ILS (instrument landing systems). ILS have been in service within the U.S. for almost 50 years. In a commercial ILS, two partially overlapping beams of UHF (109 to 126 MHz) are broadcast from an antenna array so that their overlapping region defines the centerline of the runway. This is called a localizer system and is responsible for horizontal alignment of the approach. One beam is modulated with a 150-Hz tone, while the other with a 90-Hz tone. Through comparison of the modulation depths of both tones, an autopilot system aligns the approaching aircraft with the runway centerline. A similar system called a glide-slope (GS) exists in the 320-to-330MHz band for vertical alignment of the approach. While this technology has been proven reliable for millions of commercial flights annually, its UHF nature limits

Evaluation of a Pair-Wise Conflict Detection and Resolution Algorithm in a Multiple Aircraft Scenario

NASA Technical Reports Server (NTRS)

Carreno, Victor A.

2002-01-01

The KB3D algorithm is a pairwise conflict detection and resolution (CD&R) algorithm. It detects and generates trajectory vectoring for an aircraft which has been predicted to be in an airspace minima violation within a given look-ahead time. It has been proven, using mechanized theorem proving techniques, that for a pair of aircraft, KB3D produces at least one vectoring solution and that all solutions produced are correct. Although solutions produced by the algorithm are mathematically correct, they might not be physically executable by an aircraft or might not solve multiple aircraft conflicts. This paper describes a simple solution selection method which assesses all solutions generated by KB3D and determines the solution to be executed. The solution selection method and KB3D are evaluated using a simulation in which N aircraft fly in a free-flight environment and each aircraft in the simulation uses KB3D to maintain separation. Specifically, the solution selection method filters KB3D solutions which are procedurally undesirable or physically not executable and uses a predetermined criteria for selection.

Method and System for Dynamic Automated Corrections to Weather Avoidance Routes for Aircraft in En Route Airspace

NASA Technical Reports Server (NTRS)

McNally, B. David (Inventor); Erzberger, Heinz (Inventor); Sheth, Kapil (Inventor)

2015-01-01

A dynamic weather route system automatically analyzes routes for in-flight aircraft flying in convective weather regions and attempts to find more time and fuel efficient reroutes around current and predicted weather cells. The dynamic weather route system continuously analyzes all flights and provides reroute advisories that are dynamically updated in real time while the aircraft are in flight. The dynamic weather route system includes a graphical user interface that allows users to visualize, evaluate, modify if necessary, and implement proposed reroutes.

Proceedings of the F-8 Digital Fly-By-Wire and Supercritical Wing First Flight's 20th Anniversary Celebration. Volume 2; Bibliography Appendices

NASA Technical Reports Server (NTRS)

Hodge, Kenneth E. (Compiler); Kellogg, Yvonne (Editor)

1996-01-01

A technical symposium, aircraft display dedication, and pilots' panel discussion were held on May 27, 1992. to commemorate the 20th anniversary of the first flights of the F-8 Digital Fly-By-Wire (DFBW) and Supercritical Wing (SCW) research aircraft. The symposium featured technical presentations by former key government and industry participants in the advocacy, design, aircraft modification, and flight research program activities. The DFBW and SCW technical contributions are cited. A dedication ceremony marked permanent display of both program aircraft. The panel discussion participants included eight of the eighteen research and test pilots who flew these experimental aircraft. Pilots' remarks include descriptions of their most memorable flight experiences. The report also includes a survey of the Gulf Air War, an after-dinner presentation by noted aerospace author and historian Dr. Richard Hallion.

RARE EARTH ELEMENTS IN FLY ASHES AS POTENTIAL INDICATORS OF ANTHROPOGENIC SOIL CONTAMINATION

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

Mattigod, Shas V.

2003-08-01

Studies of rare earth element (REE) content of disposed fly ashes and their potential mobility were neglected for decades because these elements were believed to be environmentally benign. A number of recent studies have now shown that REE may pose a long-term risk to the biosphere. Therefore, there is a critical need to study the REE concentrations in fly ash and their potential mobilization and dispersal upon disposal in the environment. We analyzed the REE content of bulk, size fractionated, and density separated fractions of three fly ash samples derived from combustion of sub bituminous coals from the western Unitedmore » States and found that the concentrations of these elements in bulk ashes were within the range typical of fly ashes derived from coals from the North American continent. The concentrations of light rare earth elements (LREE) such as La, Ce, and Nd, however, tended towards the higher end of the concentration range whereas, the concentrations of middle rare earth elements (MREE) (Sm and Eu) and heavy rare earth elements (HREE) (Lu) were closer to the lower end of the observed range for North American fly ashes. The concentrations of REE did not show any significant enrichment with decreasing particle size, this is typical of nonvolatile lithophilic element behavior during the combustion process. The lithophilic nature of REE was also confirmed by their concentrations in heavy density fractions of these fly ashes being on average about two times more enriched than the concentrations in the light density fractions. Shale normalized average of REE concentrations of fly ashes and coals revealed significant positive anomalies for Eu and Dy. Because of these distinctive positive anomalies of Eu and Dy, we believe that fly ash contamination of soils can be fingerprinted and distinguished from other sources of anthropogenic REE inputs in to the environment.« less

Combat aircraft operations: Training requirements for the German Air Force tactical flying units and the noise problem

NASA Astrophysics Data System (ADS)

Jertz, W.

1992-04-01

The deterrence potential of an Air Force, and by that the capability to fulfill their mission in times of war, relies on threat oriented training in peacetime. Low level flying is a major tactical means to help aircrews reduce the anticipated threat imposed to them by enemy air defence systems to an acceptable degree. The demand for this capability applies also to air defence tasks against attacking fighter bombers. Military low level flying requires a high degree of proficiency, which can only be reached and maintained by constant training. A high performance level is then the key to air power. The possibilities for this kind of necessary training are restricted by superior demands concerning, amongst others, flying safety and environmental reasons. Too intensive restrictions might reduce the fighting capability of the wings to such an extent, that mission fulfillment could be seriously endangered.

Fly ash reinforced thermoplastic vulcanizates obtained from waste tire powder.

PubMed

Sridhar, V; Xiu, Zhang Zhen; Xu, Deng; Lee, Sung Hyo; Kim, Jin Kuk; Kang, Dong Jin; Bang, Dae-Suk

2009-03-01

Novel thermoplastic composites made from two major industrial and consumer wastes, fly ash and waste tire powder, have been developed. The effect of increasing fly ash loadings on performance characteristics such as tensile strength, thermal, dynamic mechanical and magnetic properties has been investigated. The morphology of the blends shows that fly ash particles have more affinity and adhesion towards the rubbery phase when compared to the plastic phase. The fracture surface of the composites shows extensive debonding of fly ash particles. Thermal analysis of the composites shows a progressive increase in activation energy with increase in fly ash loadings. Additionally, morphological studies of the ash residue after 90% thermal degradation shows extensive changes occurring in both the polymer and filler phases. The processing ability of the thermoplastics has been carried out in a Monsanto processability testing machine as a function of shear rate and temperature. Shear thinning behavior, typical of particulate polymer systems, has been observed irrespective of the testing temperatures. Magnetic properties and percolation behavior of the composites have also been evaluated.

Child restraint systems for civil aircraft.

DOT National Transportation Integrated Search

1978-03-01

Child restraint systems have been developed to provide protection to children involved in automobile crashes. These systems are not yet approved for use in civil aircraft. Six typical systems were exposed to controlled impacts on a test sled to simul...

Children restraint systems for civil aircraft.

DOT National Transportation Integrated Search

1978-03-01

Child restraint systems have been developed to provide protection to children involved in automobile crashes. These systems are not yet approved for use in civil aircraft. Six typical systems were exposed to controlled impacts on a test sled to simul...

Honey bees (Apis mellifera ligustica) swing abdomen to dissipate residual flying energy landing on a wall

NASA Astrophysics Data System (ADS)

Zhao, Jieliang; Huang, He; Yan, Shaoze

2017-03-01

Whether for insects or for aircrafts, landing is one of the indispensable links in the verification of airworthiness safety. The mechanisms by which insects achieve a fast and stable landing remain unclear. An intriguing example is provided by honeybees (Apis mellifera ligustica), which use the swinging motion of their abdomen to dissipate residual flying energy and to achieve a smooth, stable, and quick landing. By using a high-speed camera, we observed that touchdown is initiated by honeybees extending their front legs or antennae and then landing softly on a wall. After touchdown, they swing the rest of their bodies until all flying energy is dissipated. We suggested a simplified model with mass-spring dampers for the body of the honeybee and revealed the mechanism of flying energy transfer and dissipation in detail. Results demonstrate that body translation and abdomen swinging help honeybees dissipate residual flying energy and orchestrate smooth landings. The initial kinetic energy of flying is transformed into the kinetic energy of the abdomen's rotary movement. Then, the kinetic energy of rotary movement is converted into thermal energy during the swinging cycle. This strategy provides more insight into the mechanism of insect flying, which further inspires better design on aerial vehicle with better landing performance.

An Investigation of Candidate Sensor-Observable Wake Vortex Strength Parameters for the NASA Aircraft Vortex Spacing System (AVOSS)

NASA Technical Reports Server (NTRS)

Tatnall, Chistopher R.

1998-01-01

The counter-rotating pair of wake vortices shed by flying aircraft can pose a threat to ensuing aircraft, particularly on landing approach. To allow adequate time for the vortices to disperse/decay, landing aircraft are required to maintain certain fixed separation distances. The Aircraft Vortex Spacing System (AVOSS), under development at NASA, is designed to prescribe safe aircraft landing approach separation distances appropriate to the ambient weather conditions. A key component of the AVOSS is a ground sensor, to ensure, safety by making wake observations to verify predicted behavior. This task requires knowledge of a flowfield strength metric which gauges the severity of disturbance an encountering aircraft could potentially experience. Several proposed strength metric concepts are defined and evaluated for various combinations of metric parameters and sensor line-of-sight elevation angles. Representative populations of generating and following aircraft types are selected, and their associated wake flowfields are modeled using various wake geometry definitions. Strength metric candidates are then rated and compared based on the correspondence of their computed values to associated aircraft response values, using basic statistical analyses.

Stable hovering of a jellyfish-like flying machine

PubMed Central

Ristroph, Leif; Childress, Stephen

2014-01-01

Ornithopters, or flapping-wing aircraft, offer an alternative to helicopters in achieving manoeuvrability at small scales, although stabilizing such aerial vehicles remains a key challenge. Here, we present a hovering machine that achieves self-righting flight using flapping wings alone, without relying on additional aerodynamic surfaces and without feedback control. We design, construct and test-fly a prototype that opens and closes four wings, resembling the motions of swimming jellyfish more so than any insect or bird. Measurements of lift show the benefits of wing flexing and the importance of selecting a wing size appropriate to the motor. Furthermore, we use high-speed video and motion tracking to show that the body orientation is stable during ascending, forward and hovering flight modes. Our experimental measurements are used to inform an aerodynamic model of stability that reveals the importance of centre-of-mass location and the coupling of body translation and rotation. These results show the promise of flapping-flight strategies beyond those that directly mimic the wing motions of flying animals. PMID:24430122

Noninvasive analysis of microbiome dynamics in the fruit fly Drosophila melanogaster.

PubMed

Fink, Christine; Staubach, Fabian; Kuenzel, Sven; Baines, John F; Roeder, Thomas

2013-11-01

The diversity and structure of the intestinal microbial community has a strong influence on life history. To understand how hosts and microbes interact, model organisms with comparatively simple microbial communities, such as the fruit fly (Drosophila melanogaster), offer key advantages. However, studies of the Drosophila microbiome are limited to a single point in time, because flies are typically sacrificed for DNA extraction. In order to test whether noninvasive approaches, such as sampling of fly feces, could be a means to assess fly-associated communities over time on the same cohort of flies, we compared the microbial communities of fly feces, dissected fly intestines, and whole flies across three different Drosophila strains. Bacterial species identified in either whole flies or isolated intestines were reproducibly found in feces samples. Although the bacterial communities of feces and intestinal samples were not identical, they shared similarities and obviously the same origin. In contrast to material from whole flies and intestines, feces samples were not compromised by Wolbachia spp. infections, which are widespread in laboratory and wild strains. In a proof-of-principle experiment, we showed that simple nutritional interventions, such as a high-fat diet or short-term starvation, had drastic and long-lasting effects on the micobiome. Thus, the analysis of feces can supplement the toolbox for microbiome studies in Drosophila, unleashing the full potential of such studies in time course experiments where multiple samples from single populations are obtained during aging, development, or experimental manipulations.

Assessment of Attractiveness of Plants as Roosting Sites for the Melon Fly, Bactrocera cucurbitae, and Oriental Fruit Fly, Bactrocera dorsalis

PubMed Central

McQuate, Grant T.; Vargas, Roger I.

2007-01-01

The use of toxic protein bait sprays to suppress melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), populations typically involves application to vegetation bordering agricultural host areas where the adults seek shelter (“roost”). Although bait spray applications for suppression of oriental fruit fly, Bactrocera dorsalis (Hendel), populations have traditionally been applied to the host crop, rather than to crop borders, roosting by oriental fruit flies in borders of some crop species, such as papaya, Carica papaya L. (Brassicales: Caricaceae), suggests that bait spray applications to crop borders could also help in suppression of B. dorsalis populations. In order to develop improved recommendations for application of bait sprays to border plants for suppression of melon fly and oriental fruit fly populations, the relative attractiveness of a range of plant species, in a vegetative (non-flowering) stage, was tested to wild melon fly and oriental fruit fly populations established in a papaya orchard in Hawaii. A total of 20 plant species were evaluated, divided into four categories: 1) border plants, including corn, Zea mays L. (Poales: Poaceae), windbreaks and broad-leaved ornamentals, 7 species; 2) weed plants commonly found in agricultural fields in Hawaii, 6 species; 3) host crop plants, 1 species- zucchini, Cucurbita pepo L. (Violales: Curcurbitaceae), and 4) locally grown fruit trees, 6 species. Plants were established in pots and placed in an open field, in clusters encircling protein bait traps, 20 m away from the papaya orchard. Castor bean, Ricinus communis L. (Euphorbiales: Euphorbiaceae), panax, Polyscias guilfoylei (Bull) Bailey (Apiales: Araliaceae), tiger's claw, Erythnna variegata L. (Fabales: Fabaceae), and guava, Psidium guajava L. (Myrtales: Myrtaceae) were identified as preferred roosting hosts for the melon fly, and tiger's claw, panax, castor bean, Canada cocklebur, Xanthium strumarium L. (Asterales: Asteraceae

Project ARES 2: High-altitude battery-powered aircraft

NASA Technical Reports Server (NTRS)

1991-01-01

A high-altitude, battery-powered, propeller-driven aircraft was designed and is being built by undergraduate students at California State University, Northridge. The aircraft will fly at an altitude of 104,000 ft at Mach 0.2 (190 ft/sec) and will be instrumented to record flight performance data, including low Reynolds number propeller and airfoil information. This project will demonstrate the feasibility of electric-powered flight in a low-density, low-temperature Earth environment that models the atmosphere of Mars. Data collected will be used to design a Mars aircraft to investigate the surface of Mars prior to manned missions. The instrumented payload and the mission profile for the high-altitude Earth flight were determined. Detailed aerodynamic and structural analyses were performed. Control, tracking, and data recording subsystems were developed. Materials were obtained and fabrication begun. The aircraft has a 32-ft wing span, a wing area of 105 sq ft, is 17.5 ft long, has a 12-in payload bay, and weighs 42 lb. It is composed primarily of lightweight materials, including Mylar, and composite materials, including graphite/epoxy and aramid core honeycomb sandwich. Low-altitude flight testing to check guidance and control systems and to calibrate data-gathering instruments will take place this summer, followed shortly by the 104,000-ft flight.

To Err is Human Case Reports of Two Military Aircraft Accidents

PubMed Central

Dikshit, Mohan B

2010-01-01

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

An Indispensable Ingredient: Flight Research and Aircraft Design

NASA Technical Reports Server (NTRS)

Gorn, Michael H.

2003-01-01

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:

Dryden/Edwards 1994 Thrust-Vectoring Aircraft Fleet - F-18 HARV, X-31, F-16 MATV

NASA Technical Reports Server (NTRS)

1994-01-01

The three thrust-vectoring aircraft at Edwards, California, each capable of flying at extreme angles of attack, cruise over the California desert in formation during flight in March 1994. They are, from left, NASA's F-18 High Alpha Research Vehicle (HARV), flown by the NASA Dryden Flight Research Center; the X-31, flown by the X-31 International Test Organization (ITO) at Dryden; and the Air Force F-16 Multi-Axis Thrust Vectoring (MATV) aircraft. All three aircraft were flown in different programs and were developed independently. The NASA F-18 HARV was a testbed to produce aerodynamic data at high angles of attack to validate computer codes and wind tunnel research. The X-31 was used to study thrust vectoring to enhance close-in air combat maneuvering, while the F-16 MATV was a demonstration of how thrust vectoring could be applied to operational aircraft.

High altitude aircraft remote sensing during the 1988 Yellowstone National Park wildfires

NASA Technical Reports Server (NTRS)

Ambrosia, Vincent G.

1990-01-01

An overview is presented of the effects of the wildfires that occurred in the Yellowstone National Park during 1988 and the techniques employed to combat these fires with the use of remote sensing. The fire management team utilized King-Air and Merlin aircraft flying night missions with a thermal IR line-scanning system. NASA-Ames Research Center assisted with an ER-2 high altitude aircraft with the ability to down-link active data from the aircraft via a teledetection system. The ER-2 was equipped with a multispectral Thematic Mapper Simulator scanner and the resultant map data and video imagery was provided to the fire command personnel for field evaluation and fire suppression activities. This type of information proved very valuable to the fire control management personnel and to the continuing ecological research goals of NASA-Ames scientists analyzing the effects of burn type and severity on ecosystem recovery and development.

Dryden B-52 Launch Aircraft on Edwards AFB Runway

NASA Technical Reports Server (NTRS)

1996-01-01

NASA's venerable workhorse, the B-52 mothership, rolls out on the Edwards AFB runway after a test flight in 1996. Over the course of more than 40 years, the B-52 launched numerous experimental aircraft, ranging from the X-15 to the X-38, and was also used as a flying testbed for a variety of other research projects. 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

Stable fly, house fly (Diptera: Muscidae), and other nuisance fly development in poultry litter associated with horticultural crop production.

PubMed

Cook, D F; Dadour, I R; Keals, N J

1999-12-01

Poultry litter usage in horticultural crop production is a contributor to nuisance fly populations, in particular stable flies (Stomoxys calcitrans L.) and house flies (Musca domestica L.). Extrapolation of adult emergence data suggests that approximately 1.5 million house flies and 0.2 million stable flies are emerging on average from every hectare of poultry litter applied as a preplant fertilizer for vegetable production in Perth, Western Australia. To a lesser extent, sideband applications to established crops may allow for the development of 0.5 million house flies and 45,000 stable flies per hectare. However, up to 1 million house flies, 0.45 million lesser house flies, Fannia cannicularis L., and 11,000 stable flies per hectare may be produced from surface dressings of poultry litter associated with turf production. Other nuisance flies present in poultry litter included the false stable fly, Muscina stabulans (Fallén), bluebodied blowfly, Calliphora dubia Hardy, black carrion fly, Hydrotaea rostrata Robineau-Desvoidy, Australian sheep blowfly, Lucilia cuprina Wiedemann, and flesh flies (Sarcophagidae). Only house flies developed in poultry litter for the first 4 d after application in the field. Stable flies were not present in poultry litter until 4-7 d after application, and were the only fly species developing in litter > 9 d after application.

Survey of piloting factors in V/STOL aircraft with implications for flight control system design

NASA Technical Reports Server (NTRS)

Ringland, R. F.; Craig, S. J.

1977-01-01

Flight control system design factors involved for pilot workload relief are identified. Major contributors to pilot workload include configuration management and control and aircraft stability and response qualities. A digital fly by wire stability augmentation, configuration management, and configuration control system is suggested for reduction of pilot workload during takeoff, hovering, and approach.

Simulation Tools Model Icing for Aircraft Design

NASA Technical Reports Server (NTRS)

2012-01-01

Here s a simple science experiment to try: Place an unopened bottle of distilled water in your freezer. After 2-3 hours, if the water is pure enough, you will notice that it has not frozen. Carefully pour the water into a bowl with a piece of ice in it. When it strikes the ice, the water will instantly freeze. One of the most basic and commonly known scientific facts is that water freezes at around 32 F. But this is not always the case. Water lacking any impurities for ice crystals to form around can be supercooled to even lower temperatures without freezing. High in the atmosphere, water droplets can achieve this delicate, supercooled state. When a plane flies through clouds containing these droplets, the water can strike the airframe and, like the supercooled water hitting the ice in the experiment above, freeze instantly. The ice buildup alters the aerodynamics of the plane - reducing lift and increasing drag - affecting its performance and presenting a safety issue if the plane can no longer fly effectively. In certain circumstances, ice can form inside aircraft engines, another potential hazard. NASA has long studied ways of detecting and countering atmospheric icing conditions as part of the Agency s efforts to enhance aviation safety. To do this, the Icing Branch at Glenn Research Center utilizes a number of world-class tools, including the Center s Icing Research Tunnel and the NASA 607 icing research aircraft, a "flying laboratory" for studying icing conditions. The branch has also developed a suite of software programs to help aircraft and icing protection system designers understand the behavior of ice accumulation on various surfaces and in various conditions. One of these innovations is the LEWICE ice accretion simulation software. Initially developed in the 1980s (when Glenn was known as Lewis Research Center), LEWICE has become one of the most widely used tools in icing research and aircraft design and certification. LEWICE has been transformed over

Deicing System Protects General Aviation Aircraft

NASA Technical Reports Server (NTRS)

2007-01-01

Kelly Aerospace Thermal Systems LLC worked with researchers at Glenn Research Center on deicing technology with assistance from the Small Business Innovation Research (SBIR) program. Kelly Aerospace acquired Northcoast Technologies Ltd., a firm that had conducted work on a graphite foil heating element under a NASA SBIR contract and developed a lightweight, easy-to-install, reliable wing and tail deicing system. Kelly Aerospace engineers combined their experiences with those of the Northcoast engineers, leading to the certification and integration of a thermoelectric deicing system called Thermawing, a DC-powered air conditioner for single-engine aircraft called Thermacool, and high-output alternators to run them both. Thermawing, a reliable anti-icing and deicing system, allows pilots to safely fly through ice encounters and provides pilots of single-engine aircraft the heated wing technology usually reserved for larger, jet-powered craft. Thermacool, an innovative electric air conditioning system, uses a new compressor whose rotary pump design runs off an energy-efficient, brushless DC motor and allows pilots to use the air conditioner before the engine even starts

Injury potentials of light-aircraft instrument panels.

DOT National Transportation Integrated Search

1966-04-01

Results of head-impact tests against typical light-aircraft instrument panels to determine their g time-force parameters during deformation of structure are presented for three different velocities of impact. Evaluations of the energy attenuator rece...

Maintenance cost study of rotary wing aircraft, phase 2

NASA Technical Reports Server (NTRS)

1979-01-01

The Navy's maintenance and materials management data base was used in a study to determine the feasibility of predicting unscheduled maintenance costs for the dynamic systems of military rotary wing aircraft. The major operational and design variables were identified and the direct maintenance man hours per flight hour were obtained by step-wise multiple regression analysis. Five nonmilitary helicopter users were contacted to supply data on which variables were important factors in civil applications. These uses included offshore oil exploration and support, police and fire department rescue and enforcement, logging and heavy equipment movement, and U.S. Army military operations. The equations developed were highly effective in predicting unscheduled direct maintenance man hours per flying hours for military aircraft, but less effective for commercial or public service helicopters, probably because of the longer mission durations and the much higher utilization of civil users.

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

NASA Technical Reports Server (NTRS)

Franklin, James A.; Stortz, Michael W.

1996-01-01

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

Modeling Programs Increase Aircraft Design Safety

NASA Technical Reports Server (NTRS)

2012-01-01

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

Agricultural Aircraft Aid

NASA Technical Reports Server (NTRS)

1982-01-01

Farmers are increasingly turning to aerial applications of pesticides, fertilizers and other materials. Sometimes uneven distribution of the chemicals is caused by worn nozzles, improper alignment of spray nozzles or system leaks. If this happens, job must be redone with added expense to both the pilot and customer. Traditional pattern analysis techniques take days or weeks. Utilizing NASA's wind tunnel and computer validation technology, Dr. Roth, Oklahoma State University (OSU), developed a system for providing answers within minutes. Called the Rapid Distribution Pattern Evaluation System, the OSU system consists of a 100-foot measurement frame tied in to computerized analysis and readout equipment. System is mobile, delivered by trailer to airfields in agricultural areas where OSU conducts educational "fly-ins." A fly-in typically draws 50 to 100 aerial applicators, researchers, chemical suppliers and regulatory officials. An applicator can have his spray pattern checked. A computerized readout, available in five to 12 minutes, provides information for correcting shortcomings in the distribution pattern.

A Computational Method to Quantify Fly Circadian Activity.

PubMed

Lazopulo, Andrey; Syed, Sheyum

2017-10-28

In most animals and plants, circadian clocks orchestrate behavioral and molecular processes and synchronize them to the daily light-dark cycle. Fundamental mechanisms that underlie this temporal control are widely studied using the fruit fly Drosophila melanogaster as a model organism. In flies, the clock is typically studied by analyzing multiday locomotor recording. Such a recording shows a complex bimodal pattern with two peaks of activity: a morning peak that happens around dawn, and an evening peak that happens around dusk. These two peaks together form a waveform that is very different from sinusoidal oscillations observed in clock genes, suggesting that mechanisms in addition to the clock have profound effects in producing the observed patterns in behavioral data. Here we provide instructions on using a recently developed computational method that mathematically describes temporal patterns in fly activity. The method fits activity data with a model waveform that consists of four exponential terms and nine independent parameters that fully describe the shape and size of the morning and evening peaks of activity. The extracted parameters can help elucidate the kinetic mechanisms of substrates that underlie the commonly observed bimodal activity patterns in fly locomotor rhythms.

Air to air view of Endeavour, OV-105, atop SCA flies over JSC enroute to KSC

NASA Technical Reports Server (NTRS)

1991-01-01

Air to air view shows Endeavour, Orbiter Vehicle (OV) 105, atop a Shuttle Carrier Aircraft (SCA) NASA 911, a modified Boeing 747, flying over the Clear Lake / NASA JSC area prior to a brief stopover at Ellington Field, near JSC. JSC site appears behind and below the orbiter/aircraft combination with Clear Creek and Egret Bay Blvd in the foreground and Clear Lake and Galveston Bay in the background. OV-105 rolled out at Rockwell's Palmdale facility on 04-25-91 to once more bring to four the total of NASA Shuttles available for flight assignment. It left Houston later on this day headed for another stop in Mississippi before landing in Florida on 05-07-91. This photograph was taken from a T-38 aircraft by Sheri J. Dunnette of JSC's Image Sciences Division (ISD).

Three dimensional model calculations of the global dispersion of high speed aircraft exhaust and implications for stratospheric ozone loss

NASA Technical Reports Server (NTRS)

Douglass, Anne R.; Rood, Richard B.; Jackman, Charles H.; Weaver, Clark J.

1994-01-01

Two-dimensional (zonally averaged) photochemical models are commonly used for calculations of ozone changes due to various perturbations. These include calculating the ozone change expected as a result of change in the lower stratospheric composition due to the exhaust of a fleet of supersonic aircraft flying in the lower stratosphere. However, zonal asymmetries are anticipated to be important to this sort of calculation. The aircraft are expected to be restricted from flying over land at supersonic speed due to sonic booms, thus the pollutant source will not be zonally symmetric. There is loss of pollutant through stratosphere/troposphere exchange, but these processes are spatially and temporally inhomogeneous. Asymmetry in the pollutant distribution contributes to the uncertainty in the ozone changes calculated with two dimensional models. Pollutant distributions for integrations of at least 1 year of continuous pollutant emissions along flight corridors are calculated using a three dimensional chemistry and transport model. These distributions indicate the importance of asymmetry in the pollutant distributions to evaluation of the impact of stratospheric aircraft on ozone. The implications of such pollutant asymmetries to assessment calculations are discussed, considering both homogeneous and heterogeneous reactions.

NASA aircraft technician Don Herman completes placement of the first official U.S. Centennial of Fli

NASA Technical Reports Server (NTRS)

2002-01-01

NASA aircraft technician Don Herman completes placement of the first official U.S. Centennial of Flight Commission logo on an aircraft. The honored recipient is NASA Dryden Flight Research Center's Active Aeroelastic Wing (AAW) F/A-18 research aircraft, which is poised to begin wing-warping research flights harkening back to the Wright brothers. The Centennial of Flight Commission was created by the U.S.Congress in 1999 to serve as a national and international source of information about activities to commemorate the centennial of the Wright Brothers' first powered flight on the sands of Kitty Hawk, North Carolina, on December 17, 1903. Centennial activities are scheduled for 2003 in both North Carolina and Dayton, Ohio, home of the Wrights. In addition to these celebrations, numerous historical and educational projects are anticipated on the subject of aviation and aeronautics that will be an important legacy of the centennial of powered flight.

B-747 in Flight during Vortex Study with Learjet and T-37 Fly Through the Wake

NASA Technical Reports Server (NTRS)

1974-01-01

In this 1974 NASA Flight Research Center (FRC) photograph, the two chase aircraft, a Learjet and a Cessna T-37, are shown in formation off the right wing tip of the Boeing B-747 jetliner. The two chase aircraft were used to probe the trailing wake vortices generated by the airflow around the wings of the B-747 aircraft. The vortex trail behind the right wing tip was made visible by a smoke generator mounted under the wing of the B-747 aircraft. In 1974 the NASA Flight Research Center (later Dryden Flight Research Center, Edwards, California) used a Boeing 747 as part of the overall NASA study of trailing vortices. Trailing vortices are the invisible flow of spiraling air that trails from the wings of large aircraft and can 'upset' smaller aircraft flying behind them. The 747 that NASA used was on loan from the Johnson Space Center where it was part of the Space Shuttle Program. The data gathered in the 747 studies complemented data from the previous (1973-74) joint NASA Flight Research Center and Federal Aviation Administration (FAA) Boeing727 wake vortices study. Six smoke generators were installed under the wings of the 747 to provide a visual image of the trailing vortices. The object of the experiments was to test different configurations and mechanical devices on the747 that could be used to break up or lessen the strength of the vortices. The results of the tests could lead to shorter spacing between landings and takeoffs, which, in turn, could alleviate air-traffic congestion. For approximately 30 flights the 747 was flown using various combinations of wing air spoilers in an attempt to reduce wake vortices. To evaluate the effectiveness of the different configurations, chase aircraft were flown into the vortex sheets to probe their strengths and patterns at different times. Two of the chase planes used were the Flight Research Center's Cessna T-37 and the NASA Ames Research Center's Learjet. These aircraft represented the types of smaller business jets and

Emerging nondestructive inspection methods for aging aircraft

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

Beattie, A; Dahlke, L; Gieske, J

This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with amore » discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.« less

N+3 Aircraft Concept Designs and Trade Studies. Volume 1

NASA Technical Reports Server (NTRS)

Greitzer, E. M.; Bonnefoy, P. A.; DelaRosaBlanco, E.; Dorbian, C. S.; Drela, M.; Hall, D. K.; Hansman, R. J.; Hileman, J. I.; Liebeck, R. H.; Levegren, J.;

Development of an advanced pitch active control system for a wide body jet aircraft

NASA Technical Reports Server (NTRS)

Guinn, Wiley A.; Rising, Jerry J.; Davis, Walt J.

1984-01-01

An advanced PACS control law was developed for a commercial wide-body transport (Lockheed L-1011) by using modern control theory. Validity of the control law was demonstrated by piloted flight simulation tests on the NASA Langley visual motion simulator. The PACS design objective was to develop a PACS that would provide good flying qualities to negative 10 percent static stability margins that were equivalent to those of the baseline aircraft at a 15 percent static stability margin which is normal for the L-1011. Also, the PACS was to compensate for high-Mach/high-g instabilities that degrade flying qualities during upset recoveries and maneuvers. The piloted flight simulation tests showed that the PACS met the design objectives. The simulation demonstrated good flying qualities to negative 20 percent static stability margins for hold, cruise and high-speed flight conditions. Analysis and wind tunnel tests performed on other Lockheed programs indicate that the PACS could be used on an advanced transport configuration to provide a 4 percent fuel savings which results from reduced trim drag by flying at negative static stability margins.

Magnetic levitation assisted aircraft take-off and landing (feasibility study - GABRIEL concept)

NASA Astrophysics Data System (ADS)

Rohacs, Daniel; Rohacs, Jozsef

2016-08-01

The Technology Roadmap 2013 developed by the International Air Transport Association envisions the option of flying without an undercarriage to be in operation by 2032. Preliminary investigations clearly indicate that magnetic levitation technology (MagLev) might be an appealing solution to assist the aircraft take-off and landing. The EU supported research project, abbreviated as GABRIEL, was dealing with (i) the concept development, (ii) the identification, evaluation and selection of the deployable magnetic levitation technology, (iii) the definition of the core system elements (including the required aircraft modifications, the ground-based system and airport elements, and the rendezvous control system), (iv) the analysis of the safety and security aspects, (v) the concept validation and (vi) the estimation of the proposed concept impact in terms of aircraft weight, noise, emission, cost-benefit). All results introduced here are compared to a medium size hypothetic passenger aircraft (identical with an Airbus A320). This paper gives a systematic overview of (i) the applied methods, (ii) the investigation of the possible use of magnetic levitation technology to assist the commercial aircraft take-off and landing processes and (iii) the demonstrations, validations showing the feasibility of the radically new concept. All major results are outlined.

The SnoDog: Preliminary design of a close air support aircraft

NASA Technical Reports Server (NTRS)

Ashbaugh, Scott; Bartel, Kent; Cavalli, J. R.; Chan, John; Chung, Jason; Dimaranan, Liza; Freese, Mike; Levitt, Rick; Soban, Dani

1991-01-01

U.S. military forces are presently searching for the next generation Close Air Support aircraft. The following report presents the SnoDog, a low-cost ($14.8 million) aircraft capable of operating from remote battlefields and unimproved airstrips. The configuration consists of a conventional, low aspect-ratio wing, twin booms, twin canted vertical stabilizers along with a high-mounted joined horizontal tail. A supercritical airfoil for the wing enhances aerodynamic performance, while the SnoDog's instability increases maneuverability over current close air support aircraft. Survivability was incorporated into the design by the use of a titanium tub to protect the cockpit from anti-aircraft artillery, as well as, the twin booms and retracted gear disposition. The booms aid survivability by supplying separated, redundant controls, and the landing gear are slightly exposed when retracted to enable a belly landing in emergencies. Designed to fly at Mach .76, the SnoDog is powered by two low-bypass turbofan engines. Engine accessibility and interchangeable parts make the SnoDog highly maintainable. The SnoDog is adaptable to many different missions, as it is capable of carrying advanced avionics pods, carrying external fuel tanks or refueling in-air, and carrying various types of munitions. This makes the SnoDog a multirole aircraft capable of air-to-air and air-to-ground combat. This combination of features make the SnoDog unique as a close air support aircraft, capable of meeting the U.S. military's future needs.

Aircraft disinsecting: the effectiveness of Freon-based and water-based phenothrin and permethrin aerosols*

PubMed Central

Sullivan, W. N.; Cawley, B. M.; Schechter, M. S.; Morgan, N. O.; Pal, R.

1979-01-01

In Miami, Florida, USA, passenger compartments of jet aircraft were disinsected at ”blocks away”. An application of a 20 g/litre Freon-based or water-based permethrin formulation at 35 mg of aerosol per 100 m3 was 100% effective against caged mosquitos and flies. The flammability hazard of the sprays from water-based hydrocarbon aerosols was evaluated. PMID:316739

Altus I aircraft taking off from lakebed runway

NASA Technical Reports Server (NTRS)

1997-01-01

The remotely-piloted Altus I aircraft takes off from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, were designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet.

Altus I aircraft landing on Edwards lakebed runway 23

NASA Technical Reports Server (NTRS)

1997-01-01

The remotely-piloted Altus I aircraft lands on Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, were designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet. The Altus II, the first of the two craft to be completed, made its first flight on May 1, 1996. With its engine augmented by a single-stage turbocharger, the Altus II reached an altitude of 37,000 ft during its first series of development flights at Dryden in Aug., 1996. In Oct. of that year, the Altus II was flown in an Atmospheric Radiation Measurement study for the Department of Energy's Sandia National Laboratory in Oklahoma. During the course of those flights, the Altus II set a single-flight endurance record for remotely-operated aircraft of more than 26 hours. The Altus I, completed in 1997, flew a series of development flights at Dryden that summer. Those test flights culminated with the craft reaching an altitude of 43,500 ft while carrying a simulated 300-lb payload, a record for an unmanned aircraft powered by a piston engine augmented with a single-stage turbocharger. The Altus II sustained an altitudeof 55,000 feet for four hours in 1999. A pilot in a control station on the ground flies the craft by radio

FLASH fly-by-light flight control demonstration results overview

NASA Astrophysics Data System (ADS)

Halski, Don J.

1996-10-01

The Fly-By-Light Advanced Systems Hardware (FLASH) program developed Fly-By-Light (FBL) and Power-By-Wire (PBW) technologies for military and commercial aircraft. FLASH consists of three tasks. Task 1 developed the fiber optic cable, connectors, testers and installation and maintenance procedures. Task 3 developed advanced smart, rotary thin wing and electro-hydrostatic (EHA) actuators. Task 2, which is the subject of this paper,l focused on integration of fiber optic sensors and data buses with cable plant components from Task 1 and actuators from Task 3 into centralized and distributed flight control systems. Both open loop and piloted hardware-in-the-loop demonstrations were conducted with centralized and distributed flight control architectures incorporating the AS-1773A optical bus, active hand controllers, optical sensors, optimal flight control laws in high speed 32-bit processors, and neural networks for EHA monitoring and fault diagnosis. This paper overviews the systems level testing conducted under the FLASH Flight Control task. Preliminary results are summarized. Companion papers provide additional information.

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

NASA Technical Reports Server (NTRS)

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

1985-01-01

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.

Susceptibility of black soldier fly (Diptera: Stratiomyidae) larvae and adults to four insecticides.

PubMed

Tomberlin, Jeffery K; Sheppard, D Craig; Joyce, John A

2002-06-01

Dosage-mortality regressions were determined for black soldier fly, Hermetia illucens (L.), larvae fed cyromazine or pyriproxifen treated media. Cyromazine LC50 for larvae dying before becoming prepupae ranged from 0.25 to 0.28 ppm with dosage-mortality regression slopes between 5.79 and 12.04. Cyromazine LC50s for larvae dying before emergence ranged from 0.13 to 0.19 ppm with dosage-mortality regression slopes between 3.94 and 7.69. Pyriproxifen dosage-mortality regressions were not generated for larvae failing to become prepupae since <32% mortality was recorded at the highest concentration of 1,857 ppm. LC50s for larvae failing to become adults ranged from 0.10 to 0.12 ppm with dosage mortality-regression slopes between 1.67 and 2.32. Lambda-cyhalothrin and permethrin dosage-mortality regressions were determined for wild adult black soldier flies and house flies, Musca domestica L., and for susceptible house flies. Our results indicate that the wild house fly, unlike the black soldier fly, population was highly resistant to each of these pyrethroids. Regression slopes for black soldier flies exposed to lambda-cyhalothrin were twice as steep as those determined for the wild house fly strain. Accordingly, LC50s for the black soldier fly and susceptible house fly were 10- to 30-fold lower than those determined for wild house flies. The differential sensitivity between wild black soldier flies and house flies might be due to behavioral differences. Adult house flies usually remain in animal facilities with the possibility of every adult receiving pesticide exposure, while black soldier fly adults are typically present only during emergence and oviposition thereby limiting their exposure.

GVE-Based Dynamics and Control for Formation Flying Spacecraft

NASA Technical Reports Server (NTRS)

Breger, Louis; How, Jonathan P.

2004-01-01

Formation flying is an enabling technology for many future space missions. This paper presents extensions to the equations of relative motion expressed in Keplerian orbital elements, including new initialization techniques for general formation configurations. A new linear time-varying form of the equations of relative motion is developed from Gauss Variational Equations and used in a model predictive controller. The linearizing assumptions for these equations are shown to be consistent with typical formation flying scenarios. Several linear, convex initialization techniques are presented, as well as a general, decentralized method for coordinating a tetrahedral formation using differential orbital elements. Control methods are validated using a commercial numerical propagator.

A Mathematic Model That Describes Modes of MdSGHV Transmission within House Fly Populations.

PubMed

Vallejo, Celeste R; Lee, Jo Ann; Keesling, James E; Geden, Christopher J; Lietze, Verena-Ulrike; Boucias, Drion G

2013-11-20

In this paper it is proposed that one potential component by which the Musca domestica salivary gland hypertrophy virus (MdSGHV) infects individual flies is through cuticular damage. Breaks in the cuticle allow entry of the virus into the hemocoel causing the infection. Male flies typically have a higher rate of infection and a higher rate of cuticular damage than females. A model for the transmission of MdSGHV was formulated assuming several potential and recognized means of transmission. The model yields results that are in agreement with field data that measured the infection rate in house flies on dairy farms in Florida. The results from this model indicate that MdSGHV will be maintained at a stable rate within house fly populations and support the future use of MdSGHV as a birth control agent in house fly management.

NASA's Helios Prototype aircraft taking off from the Pacific Missile Range Facility, Kauai, Hawaii,

NASA Technical Reports Server (NTRS)

2001-01-01

As a follow-on to the Centurion (and earlier Pathfinder and Pathfinder-Plus) aircraft, the solar-powered Helios Prototype is the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions in the stratosphere. Developed by AeroVironment, Inc., of Monrovia, California, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, the unique craft is intended to demonstrate two key missions: the ability to reach and sustain horizontal flight at 100,000 feet altitude on a single-day flight in 2001, and to maintain flight above 50,000 feet altitude for at least four days in 2003, with the aid of a regenerative fuel cell-based energy storage system now in development. Both of these missions will be powered by electricity derived from non-polluting solar energy. The Helios Prototype is an enlarged version of the Centurion flying wing, which flew a series of test flights at NASA's Dryden Flight Research Center in late 1998. The craft has a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of its solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. The remotely piloted, electrically powered Helios Prototype went aloft on its maiden low-altitude checkout flight Sept. 8, 1999, over Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center in the Southern California desert. The initial flight series was flown on battery power as a risk-reduction measure. In all, six flights were flown in the Helios Protoype's initial development series. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved aerodynamic efficiency, allowing the Helios

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

NASA Technical Reports Server (NTRS)

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

2006-01-01

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.

The vibro-acoustic mapping of low gravity trajectories on a Learjet aircraft

NASA Technical Reports Server (NTRS)

Grodsinsky, C. M.; Sutliff, T. J.

1990-01-01

Terrestrial low gravity research techniques have been employed to gain a more thorough understanding of basic science and technology concepts. One technique frequently used involves flying parabolic trajectories aboard the NASA Lewis Research Center Learjet aircraft. A measurement program was developed to support an isolation system conceptual design. This program primarily was intended to measure time correlated high frequency accelerations (up to 100 Hz) present at various locations throughout the Learjet during a series of trajectories and flights. As suspected, the measurements obtained revealed that the environment aboard such an aircraft can not simply be described in terms of the static level low gravity g vector obtained, but that it also must account for both rigid body and high frequency vibro-acoustic dynamics.

Improved test methods for determining lightning-induced voltages in aircraft

NASA Technical Reports Server (NTRS)

Crouch, K. E.; Plumer, J. A.

1980-01-01

A lumped parameter transmission line with a surge impedance matching that of the aircraft and its return lines was evaluated as a replacement for earlier current generators. Various test circuit parameters were evaluated using a 1/10 scale relative geometric model. Induced voltage response was evaluated by taking measurements on the NASA-Dryden Digital Fly by Wire F-8 aircraft. Return conductor arrangements as well as other circuit changes were also evaluated, with all induced voltage measurements being made on the same circuit for comparison purposes. The lumped parameter transmission line generates a concave front current wave with the peak di/dt near the peak of the current wave which is more representative of lightning. However, the induced voltage measurements when scaled by appropriate scale factors (peak current or di/dt) resulting from both techniques yield comparable results.

The IAGOS Information System: From the aircraft measurements to the users.

NASA Astrophysics Data System (ADS)

Boulanger, Damien; Thouret, Valérie; Cammas, Jean-Pierre; Petzold, Andreas; Volz-Thomas, Andreas; Gerbig, Christoph; Brenninkmeijer, Carl A. M.

2013-04-01

IAGOS (In-service Aircraft for a Global Observing System, http://www.iagos.org) aims at the provision of long-term, frequent, regular, accurate, and spatially resolved in-situ observations of atmospheric chemical composition throughout the troposphere and in the UTLS. It builds on almost 20 years of scientific and technological expertise gained in the research projects MOZAIC (Measurement of Ozone and Water Vapour on Airbus In-service Aircraft) and CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container). The European consortium includes research centres, universities, national weather services, airline operators and aviation industry. IAGOS consists of two complementary building blocks proving a unique global observation system: IAGOS-CORE deploys newly developed instrumentation for regular in-situ measurements of atmospheric chemical species both reactive and greenhouse gases (O3, CO, NOx, NOy, H2O, CO2, CH4), aerosols and cloud particles. In IAGOS-CARIBIC a cargo container is deployed monthly as a flying laboratory aboard one aircraft. Involved airlines ensure global operation of the network. Today, 5 aircraft are flying with the MOZAIC (3) or IAGOS-CORE (2) instrumentation namely 3 aircraft from Lufthansa, 1 from Air Namibia, and 1 from China Airlines Taiwan. A main improvement and new aspect of the IAGOS-CORE instrumentation compared to MOZAIC is to deliver the raw data in near real time (i.e. as soon as the aircraft lands data are transmitted). After a first and quick validation of the O3 and CO measurements, preliminary data are made available in the central database for both the MACC project (Monitoring Atmospheric Composition and Climate) and scientific research groups. In addition to recorded measurements, the database also contains added-value products such as meteorological information (tropopause height, air mass backtrajectories) and lagrangian model outputs (FLEXPART). Data access is handled by open

Flight demonstration of aircraft fuselage and bulkhead monitoring using optical fiber distributed sensing system

NASA Astrophysics Data System (ADS)

Wada, Daichi; Igawa, Hirotaka; Tamayama, Masato; Kasai, Tokio; Arizono, Hitoshi; Murayama, Hideaki; Shiotsubo, Katsuya

2018-02-01

We have developed an optical fiber distributed sensing system based on optical frequency domain reflectometry (OFDR) that uses long-length fiber Bragg gratings (FBGs). This technique obtains strain data not as a point data from an FBG but as a distributed profile within the FBG. This system can measure the strain distribution profile with an adjustable high spatial resolution of the mm or sub-mm order in real-time. In this study, we applied this OFDR-FBG technique to a flying test bed that is a mid-sized jet passenger aircraft. We conducted flight tests and monitored the structural responses of a fuselage stringer and the bulkhead of the flying test bed during flights. The strain distribution variations were successfully monitored for various events including taxiing, takeoff, landing and several other maneuvers. The monitoring was effective not only for measuring the strain amplitude applied to the individual structural parts but also for understanding the characteristics of the structural responses in accordance with the flight maneuvers. We studied the correlations between various maneuvers and strains to explore the relationship between the operation and condition of aircraft.

A Study of Vehicle Structural Layouts in Post-WWII Aircraft

NASA Technical Reports Server (NTRS)

Sensmeier, Mark D.; Samareh, Jamshid A.

2004-01-01

In this paper, results of a study of structural layouts of post-WWII aircraft are presented. This study was undertaken to provide the background information necessary to determine typical layouts, design practices, and industry trends in aircraft structural design. Design decisions are often predicated not on performance-related criteria, but rather on such factors as manufacturability, maintenance access, and of course cost. For this reason, a thorough understanding of current best practices in the industry is required as an input for the design optimization process. To determine these best practices and industry trends, a large number of aircraft structural cutaway illustrations were analyzed for five different aircraft categories (commercial transport jets, business jets, combat jet aircraft, single engine propeller aircraft, and twin-engine propeller aircraft). Several aspects of wing design and fuselage design characteristics are presented here for the commercial transport and combat aircraft categories. A great deal of commonality was observed for transport structure designs over a range of eras and manufacturers. A much higher degree of variability in structural designs was observed for the combat aircraft, though some discernable trends were observed as well.

Features of flow around the flying wing model at various attack and slip angle

NASA Astrophysics Data System (ADS)

Pavlenko, A. M.; Zanin, B. Yu.; Katasonov, M. M.

2017-10-01

Experimental study of flow features around aircraft model having "flying wing" form and belonging to the category of small-unmanned aerial vehicleswas carried out. Hot-wire anemometry and flow visualization techniques were used in the investigation to get quantitative data and streamlines pictures ofthe flow near the model surface. Evolution of vortex structures depending on the attack and slip angle was demonstrated. The possibility of flow control and reduction of flow separation zones on the wing surface by means of ledges in the form of cones was also investigated. It was shown, that the laminar-turbulent transition scenario on the flying wing model is identical to the one on a straight wing and occurs through the development of a package of unstable oscillations in the boundary layer separation.

Prediction of pilot-aircraft stability boundaries and performance contours

NASA Technical Reports Server (NTRS)

Stengel, R. F.; Broussard, J. R.

1977-01-01

Control-theoretic pilot models can provide important new insights regarding the stability and performance characteristics of the pilot-aircraft system. Optimal-control pilot models can be formed for a wide range of flight conditions, suggesting that the human pilot can maintain stability if he adapts his control strategy to the aircraft's changing dynamics. Of particular concern is the effect of sub-optimal pilot adaptation as an aircraft transitions from low to high angle-of-attack during rapid maneuvering, as the changes in aircraft stability and control response can be extreme. This paper examines the effects of optimal and sub-optimal effort during a typical 'high-g' maneuver, and it introduces the concept of minimum-control effort (MCE) adaptation. Limited experimental results tend to support the MCE adaptation concept.

Significance and survival of Enterococci during the house fly development.

PubMed

Ghosh, Anuradha; Akhtar, Mastura; Holderman, Chris; Zurek, Ludek

2014-01-01

House flies are among the most important nonbiting insect pests of medical and veterinary importance. Larvae develop in decaying organic substrates and their survival strictly depends on an active microbial community. House flies have been implicated in the ecology and transmission of enterococci, including multi-antibiotic-resistant and virulent strains of Enterococcus faecalis. In this study, eight American Type Culture Collection type strains of enterococci including Enterococcus avium, Enterococcus casseliflavus, Enterococcus durans, Enterococcus hirae, Enterococcus mundtii, Enterococcus gallinarum, Enterococcusfaecalis, and Enterococcusfaecium were evaluated for their significance in the development of house flies from eggs to adults in bacterial feeding assays. Furthermore, the bacterial colonization of the gut of teneral flies as well as the importance of several virulence traits of E. faecalis in larval mortality was assessed. Overall survival of house flies (egg to adult) was significantly higher when grown with typically nonpathogenic enterococcal species such as E. hirae (76.0% survival), E. durans (64.0%), and E. avium (64.0%) compared with that with clinically important species E. faecalis (24.0%) and E. faecium (36.0%). However, no significant differences in survival of house fly larvae were detected when grown with E. faecalis strains carrying various virulence traits, including isogenic mutants of the human clinical isolate E. faecalis V583 with in-frame deletions of gelatinase, serine protease, and capsular polysaccharide serotype C. Enterococci were commonly detected in fly puparia (range: 75-100%; concentration: 103-105 CFU/puparium);however, the prevalence of enterococci in teneral flies varied greatly: from 25.0 (E. casseliflavus) to 89.5% (E. hirae). In conclusion, depending on the species, enterococci variably support house fly larval development and colonize the gut of teneral adults. The human pathogenic species, E. faecalis and E. faecium

Aircraft Maneuvers for the Evaluation of Flying Qualities and Agility. Volume 3: Simulation Data

DTIC Science & Technology

1993-08-01

as far as what you can do. If you’re flying a T- 38, it ain’t going to happen. You know some airplanc like that is going to wing rock or you’re...rating. In high gain inputs you create an oscillation that is unpredictable in magnitude and is roughly out of phase with the stick. You are sacrificing

Greatly increased use of fly ash in hydraulic cement concrete (HCC) for pavement layers and transportation structures - volume I.

DOT National Transportation Integrated Search

2012-03-01

The purpose of this phase is to evaluate the past, current and future trends of use of fly ash in concrete and restrictions to its use. The American Coal Ash Association (ACAA) conducts an annual survey of fly ash production and use. Typically on an ...

SR-71B - in Flight with F-18 Chase Aircraft - View from Air Force Tanker

NASA Technical Reports Server (NTRS)

1996-01-01

NASA 831, an SR-71B operated by the Dryden Flight Research Center, Edwards, California, cruises over the Mojave Desert with an F/A-18 Hornet flying safety chase. They were photographed on a 1996 mission from an Air Force refueling tanker The F/A-18 Hornet is used primarily as a safety chase and support aircraft at Dryden. As support aircraft, the F-18s are used for safety chase, pilot proficiency and aerial photography. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used

Directly measured cabin pressure conditions during Boeing 747-400 commercial aircraft flights.

PubMed

Kelly, Paul T; Seccombe, Leigh M; Rogers, Peter G; Peters, Matthew J

2007-07-01

In the low pressure environment of commercial aircraft, hypoxaemia may be common and accentuated in patients with lung or heart disease. Regulations specify a cabin pressure not lower than 750 hPa but it is not known whether this standard is met. This knowledge is important in determining the hazards of commercial flight for patients and the validity of current flight simulation tests. Using a wrist-watch recording altimeter, cabin pressure was recorded at 60 s intervals on 45 flights in Boeing 747-400 aircraft with three airlines. A log was kept of aircraft altitude using the in-flight display. Change in cabin pressure during flight, relationship between aircraft altitude and cabin pressure and proportion of flight time with cabin pressure approaching the minimum specified by regulation were determined. Flight duration averaged 10 h. Average cabin pressure during flight was 846 hPa. There was a linear fall in cabin pressure as the aircraft cruising altitude increased. At 10,300 m (34,000 ft) cabin pressure was 843 hPa and changed 8 hPa for every 300 m (1000 ft) change in aircraft altitude (r(2) = 0.993; P < 0.001). Lowest cabin pressure was 792 hPa at 12 200 m (40,000 ft) but during only 2% of flight time was cabin pressure less than 800 hPa. Cabin pressure is determined only by the engineering of the aircraft and its altitude and in the present study was always higher than required by regulation. Current fitness-to-fly evaluations simulate cabin conditions that passengers will not experience on these aircraft. There may be increased risks to patients should new or older aircraft operate nearer to the present minimum standard.

Design definition study of a life/cruise fan technology V/STOL aircraft. Volume 2, addendum 2: Program risk assessment

NASA Technical Reports Server (NTRS)

1975-01-01

The results are presented of a risk assessment study conducted on two technology aircraft. The aircraft system components were reviewed and assessed for risk based on: (1) complexity relative to state-of-the-art, (2) manufacturing and qualification testing, (3) availability and delays, and (4) cost/schedule impact. These assessments were based on five risk nomenclatures: low, minor, moderate, high, and extreme. Each aircraft system was assigned an overall risk rating depending upon its contribution to the capability of the aircraft to achieve the performance goals. The slightly lower Sabreliner performance margin is due to the restricted flight envelope, the fixed landing gear, and internal fuel capacity. The Sabreliner with retractable gear and allowed to fly at its best speed and altitude would reflect performance margins similar to the New Airframe. These significant margins, inherent with the MCAIR three gas generator/three fan propulsion system, are major modifiers to risk assessment of both aircraft. The estimated risk and the associated key system and performance areas are tabulated.

[Safety provisions for recreational flying or sport with a hang-glider].

PubMed

Gennari, M; Lombardo, C

1987-01-01

The Act. n. 106 of 25th March 1985 had defined the specifications of the particular aircraft designed for hobby or sport flying as is the hang-glider. It has also provided for the issue, within six months, of special regulations aimed at "checking the psycho-physical fitness required in handling" such aircraft in additions to the technical knowledge and the information about traffic, safety, insurance regulations relevant to the matter. However, the patent default of the legislator causes the protection of hobby and sport practice of hang-gliding to be either wholly inadequate or ruled by ambiguous regulations. If, instead, the present law in force is referred to, it is deemed that--while waiting for the regulations provided for by n. 106 Act.--the Aereo Club of Italy may define as "agonistic" the practice of "hobby or sport flight" so that the checking of the "specific" fitness required by such sport comes into operation in compliance with the State Decree of 18th February 1982.

Reliability analysis of the F-8 digital fly-by-wire system

NASA Technical Reports Server (NTRS)

Brock, L. D.; Goodman, H. A.

1981-01-01

The F-8 Digital Fly-by-Wire (DFBW) flight test program intended to provide the technology for advanced control systems, giving aircraft enhanced performance and operational capability is addressed. A detailed analysis of the experimental system was performed to estimated the probabilities of two significant safety critical events: (1) loss of primary flight control function, causing reversion to the analog bypass system; and (2) loss of the aircraft due to failure of the electronic flight control system. The analysis covers appraisal of risks due to random equipment failure, generic faults in design of the system or its software, and induced failure due to external events. A unique diagrammatic technique was developed which details the combinatorial reliability equations for the entire system, promotes understanding of system failure characteristics, and identifies the most likely failure modes. The technique provides a systematic method of applying basic probability equations and is augmented by a computer program written in a modular fashion that duplicates the structure of these equations.

The Helios Prototype aircraft during initial climb-out to the west over the Pacific Ocean.

NASA Technical Reports Server (NTRS)

2001-01-01

As a follow-on to the Centurion (and earlier Pathfinder and Pathfinder-Plus) aircraft, the solar-powered Helios Prototype is the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions in the stratosphere. Developed by AeroVironment, Inc., of Monrovia, California, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, the unique craft is intended to demonstrate two key missions: the ability to reach and sustain horizontal flight at 100,000 feet altitude on a single-day flight in 2001, and to maintain flight above 50,000 feet altitude for at least four days in 2003, with the aid of a regenerative fuel cell-based energy storage system now in development. Both of these missions will be powered by electricity derived from non-polluting solar energy. The Helios Prototype is an enlarged version of the Centurion flying wing, which flew a series of test flights at NASA's Dryden Flight Research Center in late 1998. The craft has a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of its solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. The remotely piloted, electrically powered Helios Prototype went aloft on its maiden low-altitude checkout flight Sept. 8, 1999, over Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center in the Southern California desert. The initial flight series was flown on battery power as a risk-reduction measure. In all, six flights were flown in the Helios Protoype's initial development series. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved aerodynamic efficiency, allowing the Helios

Pathfinder aircraft taking off - setting new solar powered altitude record

NASA Technical Reports Server (NTRS)

1995-01-01

The Pathfinder solar-powered remotely piloted aircraft climbs to a record-setting altitude of 50,567 feet during a flight Sept. 11, 1995, at NASA's Dryden Flight Research Center, Edwards, California. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

Missile airframe simulation testbed: MANPADS (MAST-M) for test and evaluation of aircraft survivability equipment

NASA Astrophysics Data System (ADS)

Clements, Jim; Robinson, Richard; Bunt, Leslie; Robinson, Joe

2011-06-01

A number of techniques have been utilized to evaluate the performance of Aircraft Survivability Equipment (ASE) against threat Man-Portable Air Defense Systems (MANPADS). These techniques include flying actual threat MANPADS against stationary ASE with simulated aircraft signatures, testing installed ASE systems against simulated threat signatures, and laboratory hardware-in-the-loop (HWIL) testing with simulated aircraft and simulated missile signatures. All of these tests lack the realism of evaluating installed ASE against in-flight MANPADS on a terminal homing intercept path toward the actual ASE equipped aircraft. This limitation is due primarily to the current inability to perform non-destructive MANPADS/Aircraft flight testing. The U.S. Army Aviation and Missile Research and Development and Engineering Center (AMRDEC) is working to overcome this limitation with the development of a recoverable surrogate MANPADS missile system capable of engaging aircraft equipped with ASE while guaranteeing collision avoidance with the test aircraft. Under its Missile Airframe Simulation Testbed - MANPADS (MAST-M) program, the AMRDEC is developing a surrogate missile system which will utilize actual threat MANPADS seeker/guidance sections to control the flight of a surrogate missile which will perform a collision avoidance and recovery maneuver prior to intercept to insure non-destructive test and evaluation of the ASE and reuse of the MANPADS seeker/guidance section. The remainder of this paper provides an overview of this development program and intended use.

Aircraft disinsection: exposure assessment and evaluation of a new pre-embarkation method.

PubMed

Berger-Preiss, Edith; Koch, Wolfgang; Gerling, Susanne; Kock, Heiko; Klasen, Jutta; Hoffmann, Godehard; Appel, Klaus E

2006-01-01

A new "pre-embarkation" method for aircraft disinsection was investigated using two different 2% d-phenothrin containing aerosols. Five experiments in aircrafts of the type Airbus 310 (4x) and Boeing 747-400 (1x) were performed. In the absence of passengers and crew the d-phenothrin aerosol was sprayed under the seat rows and in a second step at the height of approximately 1.60 m by moving from one end of the cabin to the other. Concentration levels of d-phenothrin were determined at different time periods after application of the aerosol spray. In a B 747-400 with the air conditioning system operating the concentrations ranged between 853 and 1753 microg/m3 during and till 5 min after the beginning of spraying at different locations in the cabin. Within 5-20min after the end of the spraying concentrations of 36-205 microg/m3 and 20-40 min thereafter only ca. 1 microg d-phenothrin/m3 were detectable (average values in relation to each period of measurement). On cabin interior surfaces the median values for mainly horizontal areas ranged from 100 to 1160 ng d-phenothrin/cm2. d-Phenothrin concentrations in the air were sufficient to kill flying insects like house flies and mosquitoes within 20 min. Horizontal surfaces were 100% effective against insects up to 24 h after spraying. Doses inhaled by sprayers determined by personal measurements were calculated to be 30-235 microg d-phenothrin per 100 g spray applied (30% in the respirable fraction for Arrow Aircraft Disinsectant; 10% for Aircraft Disinsectant Denka). If passengers will board, e.g., 20 min after the end of the disinsection operation, inhalation exposure is estimated to be practically negligible. Also possible dermal exposure from residues in seats and headrests is very low for passengers during the flight. Therefore any health effects for passengers and crew members are very unlikely.

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

NASA Astrophysics Data System (ADS)

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

2014-11-01

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 typically used avionic pressure are important to take into account for other airborne sensors employed on such fast flying platforms as the HALO aircraft.

Upset Simulation and Training Initiatives for U.S. Navy Commercial Derived Aircraft

NASA Technical Reports Server (NTRS)

Donaldson, Steven; Priest, James; Cunningham, Kevin; Foster, John V.

2012-01-01

Militarized versions of commercial platforms are growing in popularity due to many logistical benefits in the form of commercial off-the-shelf (COTS) parts, established production methods, and commonality for different certifications. Commercial data and best practices are often leveraged to reduce procurement and engineering development costs. While the developmental and cost reduction benefits are clear, these militarized aircraft are routinely operated in flight at significantly different conditions and in significantly different manners than for routine commercial flight. Therefore they are at a higher risk of flight envelope exceedance. This risk may lead to departure from controlled flight and/or aircraft loss1. Historically, the risk of departure from controlled flight for military aircraft has been mitigated by piloted simulation training and engineering analysis of typical aircraft response. High-agility military aircraft simulation databases are typically developed to include high angles of attack (AoA) and sideslip due to the dynamic nature of their missions and have been developed for many tactical configurations over the previous decades. These aircraft simulations allow for a more thorough understanding of the vehicle flight dynamics characteristics at high AoA and sideslip. In recent years, government sponsored research on transport airplane aerodynamic characteristics at high angles of attack has produced a growing understanding of stall/post-stall behavior. This research along with recent commercial airline training initiatives has resulted in improved understanding of simulator-based training requirements and simulator model fidelity.2-5 In addition, inflight training research over the past decade has produced a database of pilot performance and recurrency metrics6. Innovative solutions to aerodynamically model large commercial aircraft for upset conditions such as high AoA, high sideslip, and ballistic damage, as well as capability to accurately

Computed Responses of Several Aircraft to Atmospheric Turbulence and Discrete Wind Shears

NASA Technical Reports Server (NTRS)

Jewell, W. F.; Stapleford, R. L.; Heffley, R. K.

1977-01-01

The computed RMS and peak responses due to atmospheric turbulence and discrete wind shears, respectively, are presented for several aircraft in different flight conditions. The responses are presented with and without the effects of a typical second order washout filter. A complete set of dimensional stability derivatives for each aircraft/flight condition combination evaluated is also presented.

FliO Regulation of FliP in the Formation of the Salmonella enterica Flagellum

PubMed Central

Barker, Clive S.; Meshcheryakova, Irina V.; Kostyukova, Alla S.; Samatey, Fadel A.

2010-01-01

The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extragenic bypass mutations in FliP at positions R143H or F190L. Using membrane topology prediction programs, and alkaline phosphatase or GFPuv chimeric protein fusions into the FliO protein, we demonstrated that FliO is bitopic with its N-terminus in the periplasm and C-terminus in the cytoplasm. Truncation analysis of FliO demonstrated that overexpression of FliO43–125 or FliO1–95 was able to rescue motility of the ΔfliO mutant. Further, residue leucine 91 in the cytoplasmic domain was identified to be important for function. Based on secondary structure prediction, the cytoplasmic domain, FliO43–125, should contain beta-structure and alpha-helices. FliO43–125-Ala was purified and studied using circular dichroism spectroscopy; however, this domain was disordered, and its structure was a mixture of beta-sheet and random coil. Coexpression of full-length FliO with FliP increased expression levels of FliP, but coexpression with the cytoplasmic domain of FliO did not enhance FliP expression levels. Overexpression of the cytoplasmic domain of FliO further rescued motility of strains deleted for the fliO gene expressing bypass mutations in FliP. These results suggest FliO maintains FliP stability through transmembrane domain interaction. The results also demonstrate that the cytoplasmic domain of FliO has functionality, and it presumably becomes structured while interacting with its binding partners. PMID:20941389

Development and Evaluation of an Airborne Separation Assurance System for Autonomous Aircraft Operations

NASA Technical Reports Server (NTRS)

Barhydt, Richard; Palmer, Michael T.; Eischeid, Todd M.

2004-01-01

NASA Langley Research Center is developing an Autonomous Operations Planner (AOP) that functions as an Airborne Separation Assurance System for autonomous flight operations. This development effort supports NASA s Distributed Air-Ground Traffic Management (DAG-TM) operational concept, designed to significantly increase capacity of the national airspace system, while maintaining safety. Autonomous aircraft pilots use the AOP to maintain traffic separation from other autonomous aircraft and managed aircraft flying under today's Instrument Flight Rules, while maintaining traffic flow management constraints assigned by Air Traffic Service Providers. AOP is designed to facilitate eventual implementation through careful modeling of its operational environment, interfaces with other aircraft systems and data links, and conformance with established flight deck conventions and human factors guidelines. AOP uses currently available or anticipated data exchanged over modeled Arinc 429 data buses and an Automatic Dependent Surveillance Broadcast 1090 MHz link. It provides pilots with conflict detection, prevention, and resolution functions and works with the Flight Management System to maintain assigned traffic flow management constraints. The AOP design has been enhanced over the course of several experiments conducted at NASA Langley and is being prepared for an upcoming Joint Air/Ground Simulation with NASA Ames Research Center.

Flying Quality Analysis of a JAS 39 Gripen Ministick Controller in an F/A-18 Aircraft

NASA Technical Reports Server (NTRS)

Carter, John F.; Stoliker, P. C.

2000-01-01

NASA Dryden conducted a handling qualities experiment using a small displacement centerstick controller that Saab-Scania developed for the JAS 39 Gripen aircraft. The centerstick, or ministick, was mounted in the rear cockpit of an F/A-18 aircraft. Production support flight control computers (PSFCC) provided a pilot-selectable research control system. The objectives for this experiment included determining whether the mechanical characteristics of the centerstick controller had any significant effect on the handling qualities of the F/A-18, and determining the usefulness of the PSFCCs for this kind of experiment. Five pilots evaluated closed-loop tracking tasks, including echelon and column formation flight and target following. Cooper-Harper ratings and pilot comments were collected for each maneuver. This paper describes the test system, including the PSFCCs, the Gripen centerstick, and the flight test experiment. The paper presents results of longitudinal handling qualities maneuvers, including low order equivalent systems, Neal-Smith, and controls anticipation parameter analyses. The experiment showed that, while the centerstick controller provided a different aircraft feel, few handling qualities deficiencies resulted. It also demonstrated that the PSFCCs were useful for this kind of investigation.

Uncontrolled Stability in Freely Flying Insects

NASA Astrophysics Data System (ADS)

Melfi, James, Jr.; Wang, Z. Jane

2015-11-01

One of the key flight modes of a flying insect is longitudinal flight, traveling along a localized two-dimensional plane from one location to another. Past work on this topic has shown that flying insects, unless stabilized by some external stimulus, are typically unstable to a well studied pitching instability. In our work, we examine this instability in a computational study to understand whether it is possible for either evolution or an aero-vehicle designer to stabilize longitudinal flight through changes to insect morphology, kinematics, or aerodynamic quantities. A quasi-steady wingbeat averaged flapping flight model is used to describe the insect. From this model, a number of non-dimensional parameters are identified. The effect of these parameters was then quantified using linear stability analysis, applied to various translational states of the insect. Based on our understanding of these parameters, we demonstrate how to find an intrinsically stable flapping flight sequence for a dragonfly-like flapping flier in an instantaneous flapping flight model.

Similar post-stress metabolic trajectories in young and old flies.

PubMed

Colinet, Hervé; Renault, David

2018-02-01

Homeostenosis (i.e. decline in stress resistance and resilience with age) is a fundamental notion of the biogerontology and physiology of aging. Stressful situations typically challenge metabolic homeostasis and the capacity to recover from a stress-induced metabolic disorder might be particularly compromised in senescent individuals. In the present work, we report the effects of aging on low temperature stress tolerance and metabolic profiles in Drosophila melanogaster females of different ages. Adult flies aged 4, 16, 30 and 44days were subjected to acute and chronic cold stress, and data confirmed a strong decline in cold tolerance and resilience of old flies compared to young counterparts. Using quantitative target GC-MS analysis, we found distinct metabolic phenotypes between young (4day-old) and old (44day-old) flies, with glycolytic pathways being differentially affected between the two age groups. We also compared the robustness of metabolic homeostasis in young vs. old flies when exposed to cold stress using time-series metabolic analysis. In both age groups, we found evidence of strong alteration of metabolic profiles when flies were exposed to low temperature stress. Interestingly, the temporal metabolic trajectories during the recovery period were similar in young and old flies, despite strong differences in thermotolerance. In conclusion, metabolic signatures markedly changed with age and homeostenosis was observed in the phenotypic response to cold stress. However, these changes did not reflect in different temporal homeostatic response at metabolic level. Copyright © 2017 Elsevier Inc. All rights reserved.

Aircraft stress sequence development: A complex engineering process made simple

NASA Technical Reports Server (NTRS)

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

1994-01-01

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

Biology and control of tabanids, stable flies and horn flies.

PubMed

Foil, L D; Hogsette, J A

1994-12-01

Tabanids are among the most free-living adult flies which play a role as livestock pests. A single blood meal is used as a source of energy for egg production (100-1,000 eggs per meal), and females of certain species can oviposit before a blood meal is obtained (autogeny). Therefore, the maintenance of annual populations requires successful oviposition by only 2% of females. Wild animal blood sources are usually available to maintain annual tabanid populations. Larval habitats are also independent of domestic livestock. Thus, the use of repellents or partial repellents is the only effective chemical strategy to reduce the incidence of tabanids on livestock. Permanent traps (and possibly treated silhouette traps) can be employed to intercept flies. Selective grazing or confinement can also reduce the impact of tabanids. Stable fly adults are dependent on vertebrate blood for survival and reproduction, but the amount of time spent in contact with the host is relatively small. Stable fly larvae develop in manure, spilled feed and decaying vegetation. Management of larval habitats by sanitation is the key to stable fly control. Treatment of animals with residual insecticides can aid in control; thorough application to the lower body parts of livestock is important. Proper use of modified traps, using either treated targets or solar-powered electrocution grids, can be effective in reducing stable fly populations. Adult horn flies spend the major part of their time on the host, and the larvae are confined to bovid manure. Therefore, almost any form of topical insecticide application for livestock is effective against horn flies, in the absence of insecticide resistance. Treatments should be applied when economic benefit is possible; economic gains are associated with increased weaning weights and weight gains of yearling and growing cattle. Oral chemical treatments (insect growth regulators or insecticides) administered at appropriate rates via bolus, water, food or

Study of aircraft crashworthiness for fire protection

NASA Technical Reports Server (NTRS)

Cominsky, A.

1981-01-01

Impact-survivable postcrash fire accidents were surveyed. The data base developed includes foreign and domestic accidents involving airlines and jet aircraft. The emphasis was placed on domestic accidents, airlines, and jet aircraft due principally to availability of information. Only transport category aircraft in commercial service designed under FAR Part 25 were considered. A matrix was prepared to show the relationships between the accident characteristics and the fire fatalities. Typical postcrash fire scenaries were identified. Safety concepts were developed for three engineering categories: cabin interiors - cabin subsystems; power plant - engines and fuel systems; and structural mechanics - primary and secondary structures. The parameters identified for concept evaluation are cost, effectiveness, and societal concerns. Three concepts were selected for design definition and cost and effectiveness analysis: improved fire-resistant seat materials; anti-misting kerosene; and additional cabin emergency exits.

An annotated checklist of the horse flies, deer flies, and yellow flies (Diptera: Tabanidae) of Florida

USDA-ARS?s Scientific Manuscript database

The family Tabanidae includes the horse flies, deer flies, and yellow flies and is considered a significant pest of livestock throughout the United States, including Florida. Tabanids can easily become a major pest of man, especially salt marsh species which are known to readily feed on humans and o...

Submersible Aircraft Concept Design Study

DTIC Science & Technology

2010-08-01

capable of submerging at the expense of in-air efficiency; 2. creating a low density submersible requiring dynamic lift to stay submerged at the...density solution would require some additional submergence force. Whilst dynamic lift underwater could be easily achieved by the already present...turbo-prop characteristics for the submersible aircraft concept. Turbo-props are typically specified in terms of shaft horse power ( shp ) rather than

Pathfinder aircraft taking off - setting new solar powered altitude record

NASA Technical Reports Server (NTRS)

1995-01-01

The Pathfinder solar-powered remotely piloted aircraft climbs to a record-setting altitude of 50,567 feet during a flight Sept. 11, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The flight was part of the NASA ERAST (Environmental Research Aircraft and Sensor Technology) program. The Pathfinder was designed and built by AeroVironment Inc., Monrovia, California. Solar arrays cover nearly all of the upper wing surface and produce electricity to power the aircraft's six motors. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

Simulation investigation of the effect of the NASA Ames 80-by 120-foot wind tunnel exhaust flow on light aircraft operating in the Moffett field trafffic pattern

NASA Technical Reports Server (NTRS)

Streeter, Barry G.

1986-01-01

A preliminary study of the exhaust flow from the Ames Research Center 80 by 120 Foot Wind Tunnel indicated that the flow might pose a hazard to low-flying light aircraft operating in the Moffett Field traffic pattern. A more extensive evaluation of the potential hazard was undertaken using a fixed-base, piloted simulation of a light, twin-engine, general-aviation aircraft. The simulated aircraft was flown through a model of the wind tunnel exhaust by pilots of varying experience levels to develop a data base of aircraft and pilot reactions. It is shown that a light aircraft would be subjected to a severe disturbance which, depending upon entry condition and pilot reaction, could result in a low-altitude stall or cause damage to the aircraft tail structure.

Fiber Optic Control System integration for advanced aircraft. Electro-optic and sensor fabrication, integration, and environmental testing for flight control systems

NASA Technical Reports Server (NTRS)

Seal, Daniel W.; Weaver, Thomas L.; Kessler, Bradley L.; Bedoya, Carlos A.; Mattes, Robert E.

1994-01-01

This report describes the design, development, and testing of passive fiber optic sensors and a multiplexing electro-optic architecture (EOA) for installation and flight test on a NASA-owned F-18 aircraft. This hardware was developed under the Fiber Optic Control Systems for Advanced Aircraft program, part of a multiyear NASA initiative to design, develop, and demonstrate through flight test 'fly-by-light' systems for application to advanced aircraft flight and propulsion control. This development included the design and production of 10 passive optical sensors and associated multiplexed EOA hardware based on wavelength division multiplexed (WDM) technology. A variety of sensor types (rotary position, linear position, temperature, and pressure) incorporating a broad range of sensor technologies (WDM analog, WDM digital, analog microbend, and fluorescent time rate of decay) were obtained from different manufacturers and functionally integrated with an independently designed EOA. The sensors were built for installation in a variety of aircraft locations, placing the sensors in a variety of harsh environments. The sensors and EOA were designed and built to have the resulting devices be as close as practical to a production system. The integrated system was delivered to NASA for flight testing on a NASA-owned F-18 aircraft. Development and integration testing of the system provided valuable information as to which sensor types were simplest to design and build for a military aircraft environment and which types were simplest to operate with a multiplexed EOA. Not all sensor types met the full range of performance and environmental requirements. EOA development problems provided information on directions to pursue in future fly-by-light flight control development programs. Lessons learned in the development of the EOA and sensor hardware are summarized.

Fiber Optic Control System integration for advanced aircraft. Electro-optic and sensor fabrication, integration, and environmental testing for flight control systems

NASA Astrophysics Data System (ADS)

Seal, Daniel W.; Weaver, Thomas L.; Kessler, Bradley L.; Bedoya, Carlos A.; Mattes, Robert E.

1994-11-01

This report describes the design, development, and testing of passive fiber optic sensors and a multiplexing electro-optic architecture (EOA) for installation and flight test on a NASA-owned F-18 aircraft. This hardware was developed under the Fiber Optic Control Systems for Advanced Aircraft program, part of a multiyear NASA initiative to design, develop, and demonstrate through flight test 'fly-by-light' systems for application to advanced aircraft flight and propulsion control. This development included the design and production of 10 passive optical sensors and associated multiplexed EOA hardware based on wavelength division multiplexed (WDM) technology. A variety of sensor types (rotary position, linear position, temperature, and pressure) incorporating a broad range of sensor technologies (WDM analog, WDM digital, analog microbend, and fluorescent time rate of decay) were obtained from different manufacturers and functionally integrated with an independently designed EOA. The sensors were built for installation in a variety of aircraft locations, placing the sensors in a variety of harsh environments. The sensors and EOA were designed and built to have the resulting devices be as close as practical to a production system. The integrated system was delivered to NASA for flight testing on a NASA-owned F-18 aircraft. Development and integration testing of the system provided valuable information as to which sensor types were simplest to design and build for a military aircraft environment and which types were simplest to operate with a multiplexed EOA. Not all sensor types met the full range of performance and environmental requirements. EOA development problems provided information on directions to pursue in future fly-by-light flight control development programs. Lessons learned in the development of the EOA and sensor hardware are summarized.

NASA's SR-71B and F-18 HARV aircraft left Edwards Air Force Base, Calif., on March 24, 2003

NASA Image and Video Library

2003-03-24

Dryden Flight Research Center's SR-71B Blackbird aircraft, NASA tail number 831, is destined for the Kalamazoo Air Zoo museum in Kalamazoo, Mich., and the F-18 High Angle-of-Attack Research Vehicle (HARV) aircraft, NASA tail number 840, is going to the Virginia Air and Space Center in Hampton, Va. NASA's SR-71B was one of only two SR-71 trainer aircraft built, and served NASA in that role, as well as for some high-speed research, from 1991 to 1999. The F-18 HARV provided some of the most comprehensive data on the high-angle-of-attack flight regime, flying at angles of up to 70 degrees from the horizontal. The HARV flew 385 research flights at Dryden from 1987 through 1996.

NACA Pilots at the Aircraft Engine Research Laboratory

NASA Image and Video Library

1945-07-21

The Aircraft Engine Research Laboratory’s pilot corps during the final days of World War II: from left to right, Joseph Vensel, Howard Lilly, William Swann, and Joseph Walker. William “Eb” Gough joined the group months after this photograph. These men were responsible for flying the various National Advisory Committee for Aeronautics (NACA) aircraft to test new engine modifications, study ice buildup, and determine fuel performance. Vensel, a veteran pilot from Langley, was the Chief of Flight Operations and a voice of reason at the laboratory. In April 1947 Vensel was transferred to lead the new Muroc Flight Tests Unit in California until 1966. Lilly was a young pilot with recent Navy experience. Lilly also flew in the 1946 National Air Races. He followed Vensel to Muroc in July 1947 where he became the first NACA pilot to penetrate the sound barrier. On May 3, 1948, Lilly became the first NACA pilot to die in the line of duty. Swann was a young civilian pilot when he joined the NACA. He spent his entire career at the Cleveland laboratory, and led the flight operations group from the early 1960s until 1979. Two World War II veterans joined the crew after the war. Walker was a 24-year-old P–38 reconnaissance pilot. He joined the NACA as a physicist in early 1945 but soon worked his way into the cadre of pilots. Walker later gained fame as an X-plane pilot at Muroc and was killed in a June 1966 fatal crash. Gough survived being shot down twice during the war and was decorated for flying rescue missions in occupied areas.

Solar-powered electrocuting trap for controlling house flies and stable flies (Diptera: Muscidae).

PubMed

Pickens, L G; Mills, G D

1993-09-01

A portable trap was constructed that was visually attractive to house flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), outdoors. The trap was made of a white and yellow pyramid placed on top of a white vertical base that had large cutouts in each side. Attracted flies were killed by means of solar-powered electrocuting grids. Three traps killed an average of 1,360 house flies and 1,190 stable flies per day at a manure dump and were effective in attracting flies under both cool (< 23 degrees C) and warm (> 30 degrees C) temperatures. Both species of flies were most attracted to the eastern side of the trap, but house flies preferred yellow in cool mornings and white in warm afternoons. When air temperatures were > 30 degrees C, both house flies and stable flies went into the shaded base of the trap or into tunnels. Most house flies were killed on the pyramidal top of the trap, whereas most stable flies were killed on the vertical base. Opaque fiberglass tunnels with central electrocuting grids were simpler and cheaper, although less effective, for stable flies.

Research Pilot C. Gordon Fullerton in Cockpit of TU-144LL SST Flying Laboratory

NASA Technical Reports Server (NTRS)

1998-01-01

NASA Research pilot C. Gordon Fullerton sits in cockpit of TU-144LL SST Flying Laboratory. Fullerton was one of two NASA pilots who flew the aircraft as part of a joint high speed research program. NASA teamed with American and Russian aerospace industries for an extended period in a joint international research program featuring the Russian-built Tu-144LL supersonic aircraft. The object of the program was to develop technologies for a proposed future second-generation supersonic airliner to be developed in the 21st Century. The aircraft's initial flight phase began in June 1996 and concluded in February 1998 after 19 research flights. A shorter follow-on program involving seven flights began in September 1998 and concluded in April 1999. All flights were conducted in Russia from Tupolev's facility at the Zhukovsky Air Development Center near Moscow. The centerpiece of the research program was the Tu 144LL, a first-generation Russian supersonic jetliner that was modified by its developer/builder, Tupolev ANTK (aviatsionnyy nauchno-tekhnicheskiy kompleks-roughly, aviation technical complex), into a flying laboratory for supersonic research. Using the Tu-144LL to conduct flight research experiments, researchers compared full-scale supersonic aircraft flight data with results from models in wind tunnels, computer-aided techniques, and other flight tests. The experiments provided unique aerodynamic, structures, acoustics, and operating environment data on supersonic passenger aircraft. Data collected from the research program was being used to develop the technology base for a proposed future American-built supersonic jetliner. Although actual development of such an advanced supersonic transport (SST) is currently on hold, commercial aviation experts estimate that a market for up to 500 such aircraft could develop by the third decade of the 21st Century. The Tu-144LL used in the NASA-sponsored research program was a 'D' model with different engines than were used in

Development of a crashworthy seat for commuter aircraft.

DOT National Transportation Integrated Search

1990-09-01

A series of dynamic impact tests were conducted using a prototype seat with an energy absorbing mechanism as part of the seat pan. The seat frame was designed to represent a typical commuter aircraft passenger seat. Tests were conducted in an orienta...

Groundbreaking for the NACA’s Aircraft Engine Research Laboratory

NASA Image and Video Library

1941-01-21

Local politicians and National Advisory Committee for Aeronautics (NACA) officials were on hand for the January 23, 1941 groundbreaking for the NACA’s Aircraft Engine Research Laboratory (AERL). The NACA was established in 1915 to coordinate the nation’s aeronautical research. The committee opened a research laboratory at Langley Field in 1920. By the late 1930s, however, European nations, Germany in particular, were building faster and higher flying aircraft. The NACA decided to expand with a new Ames Aeronautical Laboratory dedicated to high-speed flight and the AERL to handle engine-related research. The NACA examined a number of Midwest locations for its new engine lab before deciding on Cleveland. At the time, Cleveland possessed the nation’s most advanced airport, several key aircraft manufacturing companies, and was home to the National Air Races. Local officials were also able to broker a deal with the power company to discount its electricity rates if the large wind tunnels were operated overnight. The decision was made in October 1940, and the groundbreaking alongside the airport took place on January 23, 1941. From left to right: William Hopkins, John Berry, Ray Sharp, Frederick Crawford, George Brett, Edward Warner, Sydney Kraus, Edward Blythin, and George Lewis

Air force Thunderbirds flying above the Kennedy Space Center

NASA Image and Video Library

2007-02-01

Look -- It's a bird and a plane! A U.S. Air Force Thunderbird F-16D aircraft streaks through the sky past a slower-flying stork over the NASA News Center. The pilot is Maj. Tad Clark, who, after landing at the Shuttle Landing Facility, announced that Kennedy Space Center Visitor Complex will host the inaugural World Space Expo from Nov. 3 to 11, featuring an aerial salute by the Thunderbirds on its opening weekend. The Expo will create one of the largest displays of space artifacts, hardware and personalities ever assembled in one location with the objective to inspire, educate and engage the public by highlighting the achievements and benefits of space exploration.

Managing the horn fly (Diptera: Muscidae) using an electric walk-through fly trap.

PubMed

Watson, D W; Stringham, S M; Denning, S S; Washburn, S P; Poore, M H; Meier, A

2002-10-01

An electric walk-through fly trap was evaluated for the management of the horn fly, Hematobia irritans (L.), on dairy cattle in North Carolina over 2 yr. The trap relies on black lights and electrocution grids to attract and kill flies that are brushed from the cattle passing through. During the first season, horn fly densities were reduced from >1,400 to <200 flies per animal. Horn fly density averaged 269.2 +/- 25.8 on cattle using the walk-through fly trap twice daily, and 400.2 +/- 43.5 on the control group during the first year. The second year, seasonal mean horn fly density was 177.3 +/- 10.8 on cattle using the walk-through fly trap compared with 321.1 +/- 15.8 on the control group. No insecticides were used to control horn flies during this 2-yr study.

Modeling, simulation, and flight characteristics of an aircraft designed to fly at 100,000 feet

NASA Technical Reports Server (NTRS)

Sim, Alex G.

1991-01-01

A manned real time simulation of a conceptual vehicle, the stratoplane, was developed to study the problems associated with the flight characteristics of a large, lightweight vehicle. Mathematical models of the aerodynamics, mass properties, and propulsion system were developed in support of the simulation and are presented. The simulation was at first conducted without control augmentation to determine the needs for a control system. The unaugmented flying qualities were dominated by lightly damped dutch roll oscillations. Constant pilot workloads were needed at high altitudes. Control augmentation was studied using basic feedbacks. For the longitudinal axis, flight path angle, and pitch rate feedback were sufficient to damp the phugoid mode and to provide good flying qualities. In the lateral directional axis, bank angle, roll rate, and yaw rate feedbacks were sufficient to provide a safe vehicle with acceptable handling qualities. Intentionally stalling the stratoplane to very high angles of attack (deep stall) was studied as a means of enable safe and rapid descent. It was concluded that the deep stall maneuver is viable for this class of vehicle.

New sonic shockwave multi-element sensors mounted on a small airfoil flown on F-15B testbed aircraft

NASA Technical Reports Server (NTRS)

1996-01-01

An experimental device to pinpoint the location of a shockwave that develops in an aircraft flying at transonic and supersonic speeds was recently flight-tested at NASA's Dryden Flight Research Center, Edwards, California. The shock location sensor, developed by TAO Systems, Hampton, Va., utilizes a multi-element hot-film sensor array along with a constant-voltage anemometer and special diagnostic software to pinpoint the exact location of the shockwave and its characteristics as it develops on an aircraft surface. For this experiment, the 45-element sensor was mounted on the small Dryden-designed airfoil shown in this illustration. The airfoil was attached to the Flight Test Fixture mounted underneath the fuselage of Dryden's F-15B testbed aircraft. Tests were flown at transonic speeds of Mach 0.7 to 0.9, and the device isolated the location of the shock wave to within a half-inch. Application of this technology could assist designers of future supersonic aircraft in improving the efficiency of engine air inlets by controlling the shockwave, with a related improvement in aircraft performance and fuel economy.

Identification, analysis and monitoring of risks of freezing affecting aircraft flying over the Guadarrama Mountains (Spain)

NASA Astrophysics Data System (ADS)

Fernández-González, Sergio; Sánchez, José Luis; Gascón, Estíbaliz; Merino, Andrés; Hermida, Lucía; López, Laura; Marcos, José Luis; García-Ortega, Eduardo

2014-05-01

Freezing is one of the main causes of aircraft accidents registered over the last few decades. This means it is very important to be able to predict this situation so that aircraft can change their routes to avoid freezing risk areas. Also, by using satellites it is possible to observe changes in the horizontal and vertical extension of cloud cover likely to cause freezing in real time as well as microphysical changes in the clouds. The METEOSAT Second Generation (MSG) makes it possible to create different red-green-blue (RGB) compositions that provide a large amount of information associated with the microphysics of clouds, in order to identify super-cooled water clouds that pose a high risk of freezing to aircraft. During the winter of 2011/12 in the Guadarrama Mountains, in the centre of the Iberian Peninsula, a series of scientific flights (conducted by INTA) were organised in order to study the cloud systems that affected this region during the winter. On the flight of the 1st of February 2012, the aircraft was affected by freezing after crossing over a mountain ridge with supercooled large drops (SLD). Although freezing was not expected during that day's flight, the orography caused a series of mesoscale factors that led to the appearance of localised freezing conditions. By analysing this case, we have been able to conclude that the use of satellite images makes it possible to monitor the risk of freezing, especially under specific mesoscale circumstances. Acknowledgements S. Fernández-González acknowledges the grant supported from the FPU program (AP 2010-2093). This study was supported by the following grants: GRANIMETRO (CGL2010-15930); MICROMETEO (IPT-310000-2010-22). The authors would like to thank the INTA for its scientific flights.

Phonotactic flight of the parasitoid fly Emblemasoma auditrix (Diptera: Sarcophagidae).

PubMed

Tron, Nanina; Lakes-Harlan, Reinhard

2017-01-01

The parasitoid fly Emblemasoma auditrix locates its hosts using acoustic cues from sound producing males of the cicada Okanagana rimosa. Here, we experimentally analysed the flight path of the phonotaxis from a landmark to the target, a hidden loudspeaker in the field. During flight, the fly showed only small lateral deviations. The vertical flight direction angles were initially negative (directed downwards relative to starting position), grew positive (directed upwards) in the second half of the flight, and finally flattened (directed horizontally or slightly upwards), typically resulting in a landing above the loudspeaker. This phonotactic flight pattern was largely independent from sound pressure level or target distance, but depended on the elevation of the sound source. The flight velocity was partially influenced by sound pressure level and distance, but also by elevation. The more elevated the target, the lower was the speed. The accuracy of flight increased with elevation of the target as well as the landing precision. The minimal vertical angle difference eliciting differences in behaviour was 10°. By changing the elevation of the acoustic target after take-off, we showed that the fly is able to orientate acoustically while flying.

Evolution, epidemiology, and population genetics of black flies (Diptera: Simuliidae).

PubMed

Adler, Peter H; Cheke, Robert A; Post, Rory J

2010-10-01

More than 2000 species of black flies feed on vertebrate blood; 1.5% of all species are vectors of pathogens that cause human diseases. Of nine simuliid-borne animal diseases, only two, mansonellosis and onchocerciasis, afflict humans. Onchocerciasis is a debilitating disease infecting an estimated 40 million people in Africa, Latin America, and Yemen, whereas mansonellosis is a mild disease in the Neotropics. Cytogenetic studies of natural populations of more than 500 species of black flies have revealed that the classic morphospecies of taxonomists is typically a complex of two or more reproductively isolated entities, or sibling (cryptic) species. Most vectors of human pathogens are sibling species, each ecologically unique in traits such as breeding habitats, dispersal capabilities, and degree of vector competence. We review the evolution of black flies, the cytogenetics that have revealed about 260 cytologically distinct entities, the molecular studies that continue to expose additional hidden biodiversity, and a case study of the epidemiology of the Simulium damnosum complex, the largest species complex of blood-feeding arthropods on Earth and the premier group of black flies responsible for human onchocerciasis. Copyright 2010 Elsevier B.V. All rights reserved.

Biomechanically Induced and Controller Coupled Oscillations Experienced on the F-16XL Aircraft During Rolling Maneuvers

NASA Technical Reports Server (NTRS)

Smith, John W.; Montgomery, Terry

1996-01-01

During rapid rolling maneuvers, the F-16 XL aircraft exhibits a 2.5 Hz lightly damped roll oscillation, perceived and described as 'roll ratcheting.' This phenomenon is common with fly-by-wire control systems, particularly when primary control is derived through a pedestal-mounted side-arm controller. Analytical studies have been conducted to model the nature of the integrated control characteristics. The analytical results complement the flight observations. A three-degree-of-freedom linearized set of aerodynamic matrices was assembled to simulate the aircraft plant. The lateral-directional control system was modeled as a linear system. A combination of two second-order transfer functions was derived to couple the lateral acceleration feed through effect of the operator's arm and controller to the roll stick force input. From the combined systems, open-loop frequency responses and a time history were derived, describing and predicting an analogous in-flight situation. This report describes the primary control, aircraft angular rate, and position time responses of the F-16 XL-2 aircraft during subsonic and high-dynamic-pressure rolling maneuvers. The analytical description of the pilot's arm and controller can be applied to other aircraft or simulations to assess roll ratcheting susceptibility.

Math modeling and computer mechanization for real time simulation of rotary-wing aircraft

NASA Technical Reports Server (NTRS)

Howe, R. M.

1979-01-01

Mathematical modeling and computer mechanization for real time simulation of rotary wing aircraft is discussed. Error analysis in the digital simulation of dynamic systems, such as rotary wing aircraft is described. The method for digital simulation of nonlinearities with discontinuities, such as exist in typical flight control systems and rotor blade hinges, is discussed.

A Molecular Key for the Identification of Blow Flies in Southeastern Nebraska

USDA-ARS?s Scientific Manuscript database

The identification of blow flies (Calliphoridae) (typically the first colonizers of cadavers) is difficult, especially in the earlier instars because of their small size, similarity and simplicity in external morphology. We consider how taxonomic keys based on molecular genetic data facilitate accur...

Structure, properties, and surfactant adsorption behavior of fly ash carbon

NASA Astrophysics Data System (ADS)

Kulaots, Indrek

The objective of this research was to suggest methods by which certain problems associated with use of coal fly ash as a pozzolanic agent in concrete mixtures could be alleviated, guided by a better characterization of fly ash properties. A sample suite of eighty fly ashes was gathered from utilities across the world (mainly US-based) and included ashes from coals ranging in rank from bituminous to lignite. The widely used foam index test is used to characterize ashes with respect to their propensity to adsorb surfactants (called Air Entraining Admixtures or AEAs) used to impart freeze-thaw resistance to concrete. In ash-containing concrete mixtures, AEAs are adsorbed from the polar concrete-water solution onto non-polar unburned carbon surfaces in the ash. The AEA uptake by fly ashes only crudely correlates with the amount of carbon in the fly ash, because carbon surface area, accessibility and polarity all play a role in determining adsorption capacities. Fly ash carbon particle size distribution is also a key factor. Fine carbon particles in fly ash fractions of <106mum are responsible for about 90% of surfactant adsorption capacity. Surfactant adsorption on fly ash carbon is, in the foam index test, a dynamic process. The time of the test (typically <10 minutes) is not long enough to permit penetration of small porosity by the relatively large AEA molecules, and only the most readily available adsorption surface near the geometrical surface of the carbon particles is utilized. The nature of the foam index test was also examined, and it is recommended that a more standardized test procedure based upon pure reagents be adopted for examining the nature of fly ashes. Several possible reagents were identified. Room temperature fly ash ozonation is a powerful technique that allows increasing fly ash surface polarity in a relatively short time and thus is very effective for decreasing the AEA uptake capacity. Depending on the ozone input concentration, sample amount