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1

Modal control of an oblique wing aircraft  

NASA Technical Reports Server (NTRS)

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

Phillips, James D.

1989-01-01

2

The oblique-wing research aircraft: A test bed for unsteady aerodynamic and aeroelastic research  

NASA Technical Reports Server (NTRS)

The advantages of oblique wings have been the subject of numerous theoretical studies, wind tunnel tests, low speed flight models, and finally a low speed manned demonstrator, the AD-1. The specific objectives of the OWRA program are: (1) to establish the necessary technology base required to translate theoretical and experimental results into practical mission oriented designs; (2) to design, fabricate and flight test an oblique wing aircraft throughout a realistic flight envelope, and (3) to develop and validate design and analysis tools for asymmetric aircraft configurations. The preliminary design phase of the project is complete and has resulted in a wing configuration for which construction is ready to be initiated.

Gilyard, Glenn B.

1989-01-01

3

A piloted evaluation of an oblique-wing research aircraft motion simulation with decoupling control laws  

NASA Technical Reports Server (NTRS)

The NASA Ames Research Center developed an oblique-wing research plane from NASA's digital fly-by-wire airplane. Oblique-wing airplanes show large cross-coupling in control and dynamic behavior which is not present on conventional symmetric airplanes and must be compensated for to obtain acceptable handling qualities. The large vertical motion simulator at NASA Ames-Moffett was used in the piloted evaluation of a proposed flight control system designed to provide decoupled handling qualities. Five discrete flight conditions were evaluated ranging from low altitude subsonic Mach numbers to moderate altitude supersonic Mach numbers. The flight control system was effective in generally decoupling the airplane. However, all participating pilots objected to the high levels of lateral acceleration encountered in pitch maneuvers. In addition, the pilots were more critical of left turns (in the direction of the trailing wingtip when skewed) than they were of right turns due to the tendency to be rolled into the left turns and out of the right turns. Asymmetric side force as a function of angle of attack was the primary cause of lateral acceleration in pitch. Along with the lateral acceleration in pitch, variation of rolling and yawing moments as functions of angle of attack caused the tendency to roll into left turns and out of right turns.

Kempel, Robert W.; Mcneill, Walter E.; Gilyard, Glenn B.; Maine, Trindel A.

1988-01-01

4

An investigation of aeroelastic phenomena associated with an oblique winged aircraft  

NASA Technical Reports Server (NTRS)

Oblique wing aeroelasticity studies are reviewed. The static aeroelastic stability characteristics of oblique wing aircraft, lateral trim requirements for 1-g flight, and the dynamic aeroelastic stability behavior of oblique winged aircraft, primarily flutter, are among the topics studied. The similarities and differences between oblique winged aircraft and conventional, bilaterally symmetric, swept wing aircraft are emphasized.

Weisshaar, T. A.

1976-01-01

5

An integrated study of structures, aerodynamics and controls on the forward swept wing X-29A and the oblique wing research aircraft  

NASA Technical Reports Server (NTRS)

The results of an integrated study of structures, aerodynamics, and controls using the STARS program on two advanced airplane configurations are presented. Results for the X-29A include finite element modeling, free vibration analyses, unsteady aerodynamic calculations, flutter/divergence analyses, and an aeroservoelastic controls analysis. Good correlation is shown between STARS results and various other verified results. The tasks performed on the Oblique Wing Research Aircraft include finite element modeling and free vibration analyses.

Dawson, Kenneth S.; Fortin, Paul E.

1987-01-01

6

Decoupling control synthesis for an oblique-wing aircraft  

NASA Technical Reports Server (NTRS)

Interest in oblique-wing aircraft has surfaced periodically since the 1940's. This concept offers some substantial aerodynamic performance advantages but also has significant aerodynamic and inertial cross-coupling between the aircraft longitudinal and lateral-directional axes. This paper presents a technique for synthesizing a decoupling controller while providing the desired stability augmentation. The proposed synthesis procedure uses the concept of a real model-following control system. Feedforward gains are selected on the assumption that perfect model-following conditions are satisfied. The feedback gains are obtained by using eigensystem assignment, and the aircraft is stabilized by using partial state feedback. The effectiveness of the control laws developed in achieving the desired decoupling is illustrated by application to linearized equations of motion of an oblique-wing aircraft for a given flight condition.

Alag, G. S.; Kempel, R. W.; Pahle, J. W.

1986-01-01

7

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

NASA Technical Reports Server (NTRS)

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

Morris, Stephen James

1990-01-01

8

Aeroelastic stability analysis of the AD-1 manned oblique-wing aircraft  

NASA Technical Reports Server (NTRS)

The AD-1 manned flight test program was conducted to evaluate the stability, control and handling characteristics of oblique wing aircraft. The results of the aeroelastic stability analysis are presented for both the wing alone and the wing with ailerons. A comparison was made between the results obtained using the traditional k-method of flutter analysis and the results using the PK or British method of flutter analysis. Studies were performed using the latest version of the NASTRAN computer code as well as the PASS/FLUT program.

Rutkowski, M. J.

1977-01-01

9

Oblique wing transonic transport configuration development  

NASA Technical Reports Server (NTRS)

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

1977-01-01

10

F-8 oblique wing structural feasibility study  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

11

Aeroelastic tailoring for oblique wing lateral trim  

NASA Technical Reports Server (NTRS)

Composite material aeroelastic tailoring is presently explored as a means for the correction of the roll trim imbalance of oblique-wing aircraft configurations. The concept is demonstrated through the analysis of a realistic oblique wing by a static aeroelastic computational procedure encompassing the full potential transonic aerodynamic code FLO22 and a Ritz structural plate program that models the stiffness due to symmetrical-but-unbalanced composite wing skins. Results indicate that asymetric composite tailoring reduces the aileron deflection needed for roll equilibrium, and reduces control surface hinge moment and drag. Wing skin stresses are, however, very high.

Bohlmann, Jonathan D.; Weisshaar, Terrence A.; Eckstrom, Clinton V.

1988-01-01

12

Role of research aircraft in technology development  

NASA Technical Reports Server (NTRS)

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.

Szalai, K. J.

1984-01-01

13

Experimental Aerodynamic Characteristics of an Oblique Wing for the F-8 OWRA  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted during June-July 1987 in the NASA Ames 11-Foot Transonic Wind Tunnel to study the aerodynamic performance and stability and control characteristics of a 0.087-scale model of an F-8 airplane fitted with an oblique wing. This effort was part of the Oblique Wing Research Aircraft (OWRA) program performed in conjunction with Rockwell International. The Ames-designed, aspect ratio 10.47, tapered wing used specially designed supercritical airfoils with 0.14 thickness/chord ratio at the root and 0.12 at the 85% span location. The wing was tested at two different mounting heights above the fuselage. Performance and longitudinal stability data were obtained at sweep angles of 0deg, 30deg, 45deg, 60deg, and 65deg at Mach numbers ranging from 0.30 to 1.40. Reynolds number varied from 3.1 x 10(exp 6)to 5.2 x 10(exp 6), based on the reference chord length. Angle of attack was varied from -5deg to 18deg. The performance of this wing is compared with that of another oblique wing, designed by Rockwell International, which was tested as part of the same development program. Lateral-directional stability data were obtained for a limited combination of sweep angles and Mach numbers. Sideslip angle was varied from -5deg to +5deg. Landing flap performance was studied, as were the effects of cruise flap deflections to achieve roll trim and tailor wing camber for various flight conditions. Roll-control authority of the flaps and ailerons was measured. A novel, deflected wing tip was evaluated for roll-control authority at high sweep angles.

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

1999-01-01

14

Optimal aeroelastic design of an oblique wing structure  

NASA Technical Reports Server (NTRS)

A procedure is presented for determining the optimal cover panel thickness of a wing structure to meet specified strength and static aeroelastic divergence requirements for minimum weight. Efficient reanalysis techniques using discrete structural and aerodynamic methods are used in conjunction with redesign algorithms driven by optimality criteria. The optimality conditions for the divergence constraint are established, and expressions are obtained for derivatives of the dynamic pressure at divergence with respect to design variables. The procedure is applied to an oblique wing aircraft where strength and stiffness are critical design considerations for sizing the cover thickness of the wing structure.

Gwin, L. B.

1974-01-01

15

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

16

Aircraft fire safety research  

NASA Technical Reports Server (NTRS)

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

Botteri, Benito P.

1987-01-01

17

Aircraft as Research Tools  

NASA Technical Reports Server (NTRS)

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

1999-01-01

18

NASA research in aircraft propulsion  

NASA Technical Reports Server (NTRS)

A broad overview of the scope of research presently being supported by NASA in aircraft propulsion is presented with emphasis on Lewis Research Center activities related to civil air transports, CTOL and V/STOL systems. Aircraft systems work is performed to identify the requirements for the propulsion system that enhance the mission capabilities of the aircraft. This important source of innovation and creativity drives the direction of propulsion research. In a companion effort, component research of a generic nature is performed to provide a better basis for design and provides an evolutionary process for technological growth that increases the capabilities of all types of aircraft. Both are important.

Beheim, M. A.

1982-01-01

19

Aircraft icing research at NASA  

NASA Technical Reports Server (NTRS)

Research activity is described for: ice protection systems, icing instrumentation, experimental methods, analytical modeling for the above, and in flight research. The renewed interest in aircraft icing has come about because of the new need for All-Weather Helicopters and General Aviation aircraft. Because of increased fuel costs, tomorrow's Commercial Transport aircraft will also require new types of ice protection systems and better estimates of the aeropenalties caused by ice on unprotected surfaces. The physics of aircraft icing is very similar to the icing that occurs on ground structures and structures at sea; all involve droplets that freeze on the surfaces because of the cold air. Therefore all icing research groups will benefit greatly by sharing their research information.

Reinmann, J. J.; Shaw, R. J.; Olsen, W. A., Jr.

1982-01-01

20

NASA Aircraft Controls Research, 1983  

NASA Technical Reports Server (NTRS)

The workshop consisted of 24 technical presentations on various aspects of aircraft controls, ranging from the theoretical development of control laws to the evaluation of new controls technology in flight test vehicles. A special report on the status of foreign aircraft technology and a panel session with seven representatives from organizations which use aircraft controls technology were also included. The controls research needs and opportunities for the future as well as the role envisioned for NASA in that research were addressed. Input from the panel and response to the workshop presentations will be used by NASA in developing future programs.

Beasley, G. P. (compiler)

1984-01-01

21

Numerical solution of the full-potential equation for rotors and oblique wings using a new wake model  

NASA Technical Reports Server (NTRS)

A three-dimensional, full-potential, quasi-steady code TFAR1 is proposed for calculating the transonic flow past a lifting helicopter rotor blade and oblique wing. The TFAR1 uses a two-dimensional nonlinear wake-model that allows a jump in velocity potential to propagate with the local fluid flow in the wake. Rotor calculations were made for a single blade at an advance ratio of 0.3, a rotational tip Mach number of 0.7, and at 0-degree incidence. A 1/7-scale model of the Cobra Operational Load Survey (OLS) rotor blade is calculated, and the pressure distributions are compared to the measurements for azimuth angles 0, 30, 60, 90, 120, and 150 degrees at the 95 percent spanwise station of the OLS blade. Furthermore, an oblique wing with Korn airfoil was calculated at the high transonic free-stream Mach number of 0.9791, zero incidence, and yaw angle of 40 degrees. The TFAR1, coupled with a helicopter performance code CAMRAD (Johnson, 1981), provides a full-potential code for calculating the entire flow field for a multiple-bladed rotor in transonic lifting forward flight.

Chang, I.-C.; Tung, C.

1985-01-01

22

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

23

Subsonic Ultra Green Aircraft Research  

NASA Technical Reports Server (NTRS)

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

Bradley, Marty K.; Droney, Christopher K.

2011-01-01

24

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

NASA Video Gallery

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

25

Airborne Subscale Transport Aircraft Research Testbed: Aircraft Model Development  

NASA Technical Reports Server (NTRS)

The Airborne Subscale Transport Aircraft Research (AirSTAR) testbed being developed at NASA Langley Research Center is an experimental flight test capability for research experiments pertaining to dynamics modeling and control beyond the normal flight envelope. An integral part of that testbed is a 5.5% dynamically scaled, generic transport aircraft. This remotely piloted vehicle (RPV) is powered by twin turbine engines and includes a collection of sensors, actuators, navigation, and telemetry systems. The downlink for the plane includes over 70 data channels, plus video, at rates up to 250 Hz. Uplink commands for aircraft control include over 30 data channels. The dynamic scaling requirement, which includes dimensional, weight, inertial, actuator, and data rate scaling, presents distinctive challenges in both the mechanical and electrical design of the aircraft. Discussion of these requirements and their implications on the development of the aircraft along with risk mitigation strategies and training exercises are included here. Also described are the first training (non-research) flights of the airframe. Additional papers address the development of a mobile operations station and an emulation and integration laboratory.

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

2005-01-01

26

Improved Wind Measurements on Research Aircraft  

Microsoft Academic Search

Improved techniques for measuring horizontal and vertical wind components and state variables on research aircraft are presented. They include a filtering method for correcting ground speed and position Inertial Navigation System data with Global Positioning System data, use of moist-air thermodynamic properties in the true airspeed calculation, postflight calculation of the aircraft vertical velocity, and calibration of airflow attack and

D. Khelif; S. P. Burns; C. A. Friehe

1999-01-01

27

Advanced Instrumentation for Aircraft Icing Research.  

National Technical Information Service (NTIS)

A compact and rugged probe based on the phase Doppler method was evaluated as a means for characterizing icing clouds using airborne platforms and for advancing aircraft icing research in large scale wind tunnels. The Phase Doppler Particle Analyzer (PDPA...

W. Bachalo, J. Smith, R. Rudoff

1990-01-01

28

Research related to variable sweep aircraft development  

NASA Technical Reports Server (NTRS)

Development in high speed, variable sweep aircraft research is reviewed. The 1946 Langley wind tunnel studies related to variable oblique and variable sweep wings and results from the X-5 and the XF1OF variable sweep aircraft are discussed. A joint program with the British, evaluation of the British "Swallow", development of the outboard pivot wing/aft tail configuration concept by Langley, and the applied research program that followed and which provided the technology for the current, variable sweep military aircraft is outlined. The relative state of variable sweep as a design option is also covered.

Polhamus, E. C.; Toll, T. A.

1981-01-01

29

AD-1 with research pilot Richard E. Gray  

NASA Technical Reports Server (NTRS)

Standing in front of the AD-1 Oblique Wing research aircraft is research pilot Richard E. Gray. Richard E. Gray joined National Aeronautics and Space Administration's Johnson Space Center, Houston, Texas, in November 1978, as an aerospace research pilot. In November 1981, Dick joined the NASA's Ames-Dryden Flight Research Facility, Edwards, California, as a research pilot. Dick was a former Co-op at the NASA Flight Research Center (a previous name of the Ames-Dryden Flight Research Facility), serving as an Operations Engineer. At Ames-Dryden, Dick was a pilot for the F-14 Aileron Rudder Interconnect Program, AD-1 Oblique Wing Research Aircraft, F-8 Digital Fly-By-Wire and Pilot Induced Oscillations investigations. He also flew the F-104, T-37, and the F-15. On November 8, 1982, Gray was fatally injured in a T-37 jet aircraft while making a pilot proficiency flight. Dick graduated with a Bachelors degree in Aeronautical Engineering from San Jose State University in 1969. He joined the U.S. Navy in July 1969, becoming a Naval Aviator in January 1971, when he was assigned to F-4 Phantoms at Naval Air Station (NAS) Miramar, California. In 1972, he flew 48 combat missions in Vietnam in F-4s with VF-111 aboard the USS Coral Sea. After making a second cruise in 1973, Dick was assigned to Air Test and Evaluation Squadron Four (VX-4) at NAS Point Mugu, California, as a project pilot on various operational test and evaluation programs. In November 1978, Dick retired from the Navy and joined NASA's Johnson Space Center. At JSC Gray served as chief project pilot on the WB-57F high-altitude research projects and as the prime television chase pilot in a T-38 for the landing portion of the Space Shuttle orbital flight tests. Dick had over 3,000 hours in more than 30 types of aircraft, an airline transport rating, and 252 carrier arrested landings. He was a member of the Society of Experimental Test Pilots serving on the Board of Directors as Southwest Section Technical Adviser in 1981/1982. Richard E. Gray was born March 11, 1945 in Newport News, Virginia; he died on November 8, 1982 at Edwards, California, in a T-37 spin accident. The Ames-Dryden-1 (AD-1) aircraft was designed to investigate the concept of an oblique (pivoting) wing. The wing could be rotated on its center pivot, so that it could be set at its most efficient angle for the speed at which the aircraft was flying. NASA Ames Research Center Aeronautical Engineer Robert T. Jones conceived the idea of an oblique wing. His wind tunnel studies at Ames (Moffett Field, CA) indicated that an oblique wing design on a supersonic transport might achieve twice the fuel economy of an aircraft with conventional wings. The oblique wing on the AD-1 pivoted about the fuselage, remaining perpendicular to it during slow flight and rotating to angles of up to 60 degrees as aircraft speed increased. Analytical and wind tunnel studiesthat Jones conducted at Ames indicated that a transport-sized oblique-wing aircraft flying at speeds of up to Mach 1.4 (1.4 times the speed of sound) would have substantially better aerodynamic performance than aircraft with conventional wings. The AD-1 structure allowed the project to complete all of its technical objectives. The type of low-speed, low-cost vehicle - as expected - exhibited aeroelastic and pitch-roll-coupling effects that contributed to poor handling at sweep angles above 45 degrees. The fiberglass structure limited the wing stiffness that would have improved the handling qualities. Thus, after completion of the AD-1 project, there was still a need for a transonic oblique-wing research aircraft to assess the effects of compressibility, evaluate a more representative structure, and analyze flight performance at transonic speeds (those on either side of the speed of sound). The aircraft was delivered to the Dryden Flight Research Center, Edwards, CA, in March 1979 and its first flight was on December 21, 1979. Piloting the aircraft on that flight, as well as on its last flight on August 7, 1982, was NASA Research Pilot Thomas C. McMurtry. The AD-1

1982-01-01

30

NASA Wake Vortex Research for Aircraft Spacing  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) is addressing airport capacity enhancements during instrument meteorological conditions through the Terminal Area Productivity (TAP) program. Within TAP, the Reduced Spacing Operations (RSO) subelement at the NASA Langley Research Center is developing an Aircraft Vortex Spacing System (AVOSS). AVOSS will integrate the output of several inter-related areas to produce weather dependent, dynamic wake vortex spacing criteria. These areas include current and predicted weather conditions, models of wake vortex transport and decay in these weather conditions, real-time feedback of wake vortex behavior from sensors, and operationally acceptable aircraft/wake interaction criteria. In today's ATC system, the AVOSS could inform ATC controllers when a fixed reduced separation becomes safe to apply to large and heavy aircraft categories. With appropriate integration into the Center/TRACON Automation System (CTAS), AVOSS dynamic spacing could be tailored to actual generator/follower aircraft pairs rather than a few broad aircraft categories.

Perry, R. Brad; Hinton, David A.; Stuever, Robert A.

1996-01-01

31

VSTOL Systems Research Aircraft (VSRA) Harrier  

NASA Technical Reports Server (NTRS)

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

1994-01-01

32

The NASA aircraft icing research program  

NASA Technical Reports Server (NTRS)

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

Shaw, Robert J.; Reinmann, John J.

1987-01-01

33

Rotor systems research aircraft simulation mathematical model  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

34

Overview of high performance aircraft propulsion research  

NASA Technical Reports Server (NTRS)

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

Biesiadny, Thomas J.

1992-01-01

35

High temperature aircraft research furnace facilities  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

36

Advanced instrumentation for aircraft icing research  

NASA Technical Reports Server (NTRS)

A compact and rugged probe based on the phase Doppler method was evaluated as a means for characterizing icing clouds using airborne platforms and for advancing aircraft icing research in large scale wind tunnels. The Phase Doppler Particle Analyzer (PDPA) upon which the new probe was based is now widely recognized as an accurate method for the complete characterization of sprays. The prototype fiber optic-based probe was evaluated in simulated aircraft icing clouds and found to have the qualities essential to providing information that will advance aircraft icing research. Measurement comparisons of the size and velocity distributions made with the standard PDPA and the fiber optic probe were in excellent agreement as were the measurements of number density and liquid water content. Preliminary testing in the NASA Lewis Icing Research Tunnel (IRT) produced reasonable results but revealed some problems with vibration and signal quality at high speeds. The cause of these problems were identified and design changes were proposed to eliminate the shortcomings of the probe.

Bachalo, W.; Smith, J.; Rudoff, R.

1990-01-01

37

Aircraft Turbine Engine Control Research at NASA Glenn Research Center  

NASA Technical Reports Server (NTRS)

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

Garg, Sanjay

2013-01-01

38

YO-3A acoustics research aircraft systems manual  

NASA Technical Reports Server (NTRS)

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.

Cross, J. L.

1984-01-01

39

V/STOL tilt rotor aircraft study. Volume 5: Definition of stowed rotor research aircraft  

NASA Technical Reports Server (NTRS)

The results of a study of folding tilt rotor (stowed rotor) aircraft are presented. The effects of design cruise speed on the gross weight of a conceptual design stowed rotor aircraft are shown and a comparison is made with a conventional (non-folding) tilt rotor aircraft. A flight research stowed rotor design is presented. The program plans, including costs and schedules, are shown for the research aircraft development and a wind tunnel plan is presented for a full scale test of the aircraft.

Soule, V. A.

1973-01-01

40

Flight dynamics research for highly agile aircraft  

NASA Technical Reports Server (NTRS)

This paper highlights recent results of research conducted at the NASA Langley Research Center as part of a broad flight dynamics program aimed at developing technology that will enable future combat aircraft to achieve greatly enhanced agility capability at subsonic combat conditions. Studies of advanced control concepts encompassing both propulsive and aerodynamic approaches are reviewed. Dynamic stall phenomena and their potential impact on maneuvering performance and stability are summarized. Finally, issues of mathematical modeling of complex aerodynamics occurring during rapid, large amplitude maneuvers are discussed.

Nguyen, Luat T.

1989-01-01

41

Conceptual/preliminary design study of subsonic v/stol and stovl aircraft derivatives of the S-3A  

NASA Technical Reports Server (NTRS)

A computerized aircraft synthesis program was used to examine the feasibility and capability of a V/STOL aircraft based on the Navy S-3A aircraft. Two major airframe modifications are considered: replacement of the wing, and substitution of deflected thrust turbofan engines similar to the Pegasus engine. Three planform configurations for the all composite wing were investigated: an unconstrained span design, a design with the span constrained to 64 feet, and an unconstrained span oblique wing design. Each design was optimized using the same design variables, and performance and control analyses were performed. The oblique wing configuration was found to have the greatest potential in this application. The mission performance of these V/STOL aircraft compares favorably with that of the CTOL S-3A.

Kidwell, G. H., Jr.

1981-01-01

42

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

NASA Technical Reports Server (NTRS)

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

Baumann, Ethan; Hernandez, Joe; Ruhf, John C.

2013-01-01

43

Rotor systems research aircraft airplane configuration flight-test results  

NASA Technical Reports Server (NTRS)

The Rotor Systems Research Aircraft (RSRA) has been undergoing ground and flight tests by Ames Research Center since late 1979, primarily as a compound aircraft. The purpose was to train pilots and to check out and develop the design flight envelope established by the Sikorsky Aircraft Company. This paper reviews the preparation and flight test of the RSRA in the airplane, or fixed-wing, configuration and discusses the results of that test.

Painter, W. D.; Erickson, R. E.

1984-01-01

44

The Buffalo/Spey jet-STOL research aircraft  

NASA Technical Reports Server (NTRS)

The program to design and build a Buffalo/Spey Augmentor-Wing research aircraft is presented. The development of an internally blown flap system for the generation of powered lift is discussed. Modification, development, and testing of the Rolls-Royce Spey engine are reported. The ground tests and first flights of the aircraft are described and the application of the internally blown flap concept for short takeoff military transport aircraft is proposed.

Whittley, D. C.

1973-01-01

45

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

NASA Technical Reports Server (NTRS)

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

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

1972-01-01

46

Walter C. Williams Research Aircraft Integration Facility (RAIF)  

NASA Technical Reports Server (NTRS)

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

1996-01-01

47

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

NASA Technical Reports Server (NTRS)

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

1972-01-01

48

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden  

NASA Technical Reports Server (NTRS)

NASA and McDonnell Douglas Corporation (MDC) personnel remove protective covers from the newly arrived NASA/McDonnell Douglas Corporation X-36 Tailless Fighter Agility Research Aircraft. It arrived at NASA Dryden Flight Research Center, Edwards, California, on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.

1996-01-01

49

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden  

NASA Technical Reports Server (NTRS)

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft is steered to it's hangar at NASA Dryden Flight Research Center, Edwards, California, following arrival on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.

1996-01-01

50

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden  

NASA Technical Reports Server (NTRS)

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft in it's hangar at NASA Dryden Flight Research Center, Edwards, California, following its arrival on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.

1996-01-01

51

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden  

NASA Technical Reports Server (NTRS)

NASA and McDonnell Douglas Corporation (MDC) personnel wait to attach a hoist to the X-36 Tailless Fighter Agility Research Aircraft, which arrived at NASA Dryden Flight Research Center, Edwards, California, on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.

1996-01-01

52

X-36 Tailless Fighter Agility Research Aircraft in flight  

NASA Technical Reports Server (NTRS)

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

1997-01-01

53

X-36 Tailless Fighter Agility Research Aircraft in flight  

NASA Technical Reports Server (NTRS)

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

1997-01-01

54

X-36 Tailless Fighter Agility Research Aircraft in flight  

NASA Technical Reports Server (NTRS)

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

1997-01-01

55

Materials research for aircraft fire safety  

NASA Technical Reports Server (NTRS)

The thermochemical and flammability characteristics of two polymeric composites currently in use and seven others being considered for use as aircraft interior panels are described. The properties studied included: (1) limiting oxygen index of the composite constituents; (2) fire containment capability of the composite; (3) smoke evolution from the composite; (4) thermogravimetric analysis; (5) composition of the volatile products of thermal degradation; and (6) relative toxicity of the volatile products of pyrolysis. The performance of high-temperature laminating resins such as bismaleimides is compared with the performance of phenolics and epoxies. The relationship of increased fire safety with the use of polymers with high anaerobic char yield is shown. Processing parameters of the state-of-the-art and the advanced bismaleimide composites are detailed.

Kourtides, D. A.; Parker, J. A.; Bricker, R. W.

1976-01-01

56

STOVL aircraft simulation for integrated flight and propulsion control research  

NASA Technical Reports Server (NTRS)

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

Mihaloew, James R.; Drummond, Colin K.

1989-01-01

57

Some historical trends in the research and development of aircraft  

NASA Technical Reports Server (NTRS)

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

Spearman, M. L.

1983-01-01

58

Atmospheric analysis for airdata calibration on research aircraft  

NASA Technical Reports Server (NTRS)

In-flight airdata calibrations are used to determine the aerodynamic influence of an airplane on pitot-static pressure measurements of altitude and speed. Conventional flight-test calibration techniques are briefly reviewed and meteorological analysis methods for estimating calibration reference values of atmospheric conditions are described. There are cases where some conventional in-flight techniques are not entirely satisfactory for research aircraft because of added equipment requirements or flight envelope and location limitations. In these cases, atmospheric wind and pressure information can be used to complement conventional techniques. Accuracy of the atmospheric measurements and the variability of upper-air winds and pressure values are discussed. Results from several flight research aircraft show that wind reference calibration is generally less accurate than calibration accuracy standards for civil and research aircraft. Examples of pressure reference altimetry derived from meteorological analyses are also presented for a variety of flight research programs. These flight data show that the reference pressure accuracy provided by meteorological analyses is usually within civil aircraft and flight research airdata calibration accuracy standards. Meteorological analyses altimetry is particularly useful when it is not feasible to restrict the test airplane altitude, location, or maneuver envelope.

Ehernberger, L. J.; Haering, Edward A., Jr.; Lockhart, Mary G.; Teets, Edward H.

1992-01-01

59

Some UK-government establishment research towards quieter aircraft  

Microsoft Academic Search

This paper aims to give an impression of the scope of research programmes and development of national experimental facilities at NGTE and RAE, directed specifically towards the evolution of economic quieter aircraft. By way of introduction, the particular nature of these two Government Establishments and their widely ranging roles within the aeronautical scene are indicated. As further background to the

F. W. Armstrong; J. Williams

1976-01-01

60

The NASA research program on propulsion for supersonic cruise aircraft  

NASA Technical Reports Server (NTRS)

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

Weber, R. J.

1975-01-01

61

ENIFAIR — EU research into engine integration on future transport aircraft  

Microsoft Academic Search

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

Wolfgang Burgsmüller; Heinz Hoheisel

2000-01-01

62

NASA aircraft noise reduction research and technology program overview  

NASA Technical Reports Server (NTRS)

A brief outline of the chief areas where NASA is making efforts in aircraft noise research is given. This includes studies of the physical basis of aircraft noise and methods for accurately predicting it, the development of practical technologies for noise reduction, and the subjective response of people when exposed to aircraft noise. The JT8D Refan Program was to explore whether the noise reduction design concepts used effectively in modern high-bypass engines could also be applied practically and effectively as retrofittable modifications to existing older, low-bypass JT8D engines. A program has been completed on developing and demonstrating safe and acceptable flight procedures together with necessary airborne electronics to permit two-segment approaches under either VFR or IFR conditions.

Johnson, H. W.

1975-01-01

63

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

NASA Technical Reports Server (NTRS)

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

Howell, Charles T., III

2011-01-01

64

Quiet short-haul research aircraft familiarization document, revision 1  

NASA Technical Reports Server (NTRS)

The design features and general characteristics of the Quiet Short Haul Research Aircraft are described. Aerodynamic characteristics and performance are discussed based on predictions and early flight test data. Principle airplane systems, including the airborne data acquisition system, are also described. The aircraft was designed and built to fulfill the need for a national research facility to explore the use of upper surface blowing, propulsive lift technology in providing short takeoff and landing capability, and perform advanced experiments in various technical disciplines such as aerodynamics, propulsion, stability and control, handling qualities, avionics and flight control systems, trailing vortex phenomena, acoustics, structure and loads, operating systems, human factors, and airworthiness/certification criteria. An unusually austere approach using experimental shop practices resulted in a low cost and high research capability.

Eppel, J. C.

1981-01-01

65

An Indispensable Ingredient: Flight Research and Aircraft Design  

NASA Technical Reports Server (NTRS)

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

Gorn, Michael H.

2003-01-01

66

Pseudo Aircraft Systems - A multi-aircraft simulation system for air traffic control research  

NASA Technical Reports Server (NTRS)

Pseudo Aircraft Systems (PAS) is a computerized flight dynamics and piloting system designed to provide a high fidelity multi-aircraft real-time simulation environment to support Air Traffic Control research. PAS is composed of three major software components that run on a network of computer workstations. Functionality is distributed among these components to allow the system to execute fast enough to support real-time operation. PAS workstations are linked by an Ethernet Local Area Network, and standard UNIX socket protocol is used for data transfer. Each component of PAS is controlled and operated using a custom designed Graphical User Interface. Each of these is composed of multiple windows, and many of the windows and sub-windows are used in several of the components. Aircraft models and piloting logic are sophisticated and realistic and provide complex maneuvering and navigational capabilities. PAS will continually be enhanced with new features and improved capabilities to support ongoing and future Air Traffic Control system development.

Weske, Reid A.; Danek, George L.

1993-01-01

67

Effects of asymmetry on the dynamic stability of aircraft  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

68

NASA Dryden Flight Research Center: Unmanned Aircraft Operations  

NASA Technical Reports Server (NTRS)

This slide presentation reviews several topics related to operating unmanned aircraft in particular sharing aspects of unmanned aircraft from the perspective of a pilot. There is a section on the Global Hawk project which contains information about the first Global Hawk science mission, (i.e., Global Hawk Pacific (GloPac). Included in this information is GloPac science highlights, a listing of the GloPac Instruments. The second Global Hawk science mission was Genesis and Rapid Intensification Process (GRIP), for the NASA Hurricane Science Research Team. Information includes the instrumentation and the flights that were undertaken during the program. A section on Ikhana is next. This section includes views of the Ground Control Station (GCS), and a discussion of how the piloting of UAS is different from piloting in a manned aircraft. There is also discussion about displays and controls of aircraft. There is also discussion about what makes a pilot. The last section relates the use of Ikhana in the western states fire mission.

Pestana, Mark

2010-01-01

69

Joined-wing research airplane feasibility study  

NASA Technical Reports Server (NTRS)

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

Wolkovitch, J.

1984-01-01

70

Predesign report for the rotor systems research aircraft  

NASA Technical Reports Server (NTRS)

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

1972-01-01

71

Light transport and general aviation aircraft icing research requirements  

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

72

Airframe self-noise: Four years of research. [aircraft noise reduction for commercial aircraft  

NASA Technical Reports Server (NTRS)

A critical assessment of the state of the art in airframe self-noise is presented. Full-scale data on the intensity, spectra and directivity of this noise source are evaluated in the light of the comprehensive theory developed by Ffowcs-Williams and Hawkins. Vibration of panels on commercial aircraft is identified as a possible additional source of airframe noise. The present understanding and methods for prediction of other component sources - airfoils, struts, and cavities - are discussed, and areas for further research as well as potential methods for airframe noise reduction are identified. Finally, the various experimental methods which have been developed for airframe noise research are discussed and sample results are presented.

Hardin, J. C.

1976-01-01

73

F-15B transonic flight research testbed aircraft in flight  

NASA Technical Reports Server (NTRS)

NASA's Dryden Flight Research Center, Edwards, California, is using a modified McDonnell-Douglas F-15B aircraft as a testbed for a variety of transonic flight experiments. The twin-engine, twin-tail aircraft is shown carrying a Dryden-designed Flight Test Fixture (FTF) upon which aerodynamic experiments are mounted. The F-15B flew several flights recently in support of an experiment to determine the precise location of of sonic shock wave development as air passes over an airfoil. The F-15B is currently being prepared for the Boundary Layer Heat Experiment, which will explore potential aerodynamic drag reduction from heating the turbulent portion of the air flow that passes over the fuselage of a large aircraft. The experiment also will measure the amount of electrical power required to achieve the expected heat-induced reduction in aerodynamic drag. Six thin electric resistance heaters well be mounted in the FTF, and both unheated and heated temperatures as well as surface air pressures will be measured.

1996-01-01

74

Performance characteristics of a buoyant quad-rotor research aircraft  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

75

A structural design for a hypersonic research aircraft  

NASA Technical Reports Server (NTRS)

A research aircraft is being studied that has potential for large-scale demonstration of advanced propulsive, structural, and aerodynamic technologies for hypersonic application. Versatility is achieved through a large removable payload bay with removable thermal protection, by removable wings, and by the configuration, which considers engine-airframe integration. Design criteria have been applied to an effective heat-sink structure of Lockalloy (Be-38Al), wherein thermal stress alleviation is a prime consideration in the design. Structural analyses are being performed with the SPAR computer program. Results indicate that no critical problems exist and the resulting structural weight is within initial estimates.

Jackson, L. R.; Taylor, A. H.

1976-01-01

76

Is the Current Dominant Aircraft Design Configuration VSoE Research Innovation Fund: Final Report  

E-print Network

Is the Current Dominant Aircraft Design Configuration Optimal? VSoE Research Innovation Fund: Final that current aircraft designs are not optimal. A new design has been proposed for novel and different ways in isolation in South Africa. Original Goals 1. Test a new hypothesis about optimal aircraft design for minimum

Zhou, Chongwu

77

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

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

78

AircraftStructural National Institute for Aviation Research  

E-print Network

.niar.wichita.edu/agingaircraft Contact us #12;Aging Aircraft Lab l Engineering evaluation of aircraft structures and systems l Damage tolerance assessments of aircraft metallic structures l Investigation of corrosion and corrosion-fatigue and Empennage DADT l Boeing 787 Center Bridge Recent tests (Non-Proprietary) l KC-135 teardown analysis program

79

Research on hypersonic aircraft using pre-cooled turbojet engines  

Microsoft Academic Search

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

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

80

Overview of NASA research in fiber optics for aircraft controls  

NASA Technical Reports Server (NTRS)

The challenge of those involved in aircraft control system hardware development is to accommodate an ever-increasing complexity in aircraft control, while limiting the size and weight of the components and improving system reliability. A technology that displays promise towards this end is fiber optics. The primary advantages of employing optical fibers, passive optical sensors and optically controlled actuators are weight/volume reduction, immunity from electromagnetic effects, high bandwidth capabilities and freedom from short circuits/sparking contacts. Since 1975, NASA Lewis has been performing in-house, contract and grant research in fiber optic sensors, high temperature electro-optic switches and fly-by-light control system architecture. Passive optical sensor development is an essential yet challenging area of work and has therefore received much attention during this period. A major effort to develop fly-by-light control system technology, known as the Fiber Optic Control System Integration (FOCSI) program, was initiated in 1985 as a cooperative effort between NASA and DOD. Phase 1 of FOCSI, completed in 1986, was aimed at the design of a fiber optic integrated propulsion/flight control system. Phase 2 will provide subcomponent and system development and system testing. In addition to a summary of the benefits of fiber optics, the FOCSI program, sensor advances, and future directions in the NASA Lewis program are discussed.

Seng, Gary T.

1988-01-01

81

HAI: A new TDLAS hygrometer for the HALO research aircraft  

NASA Astrophysics Data System (ADS)

Water vapor is the most important greenhouse gas in the Earth's atmosphere and a key component for several physical and chemical processes. Therefore it is a key parameter to be measured during most research campaigns. The Hygrometer for Atmospheric Investigations (HAI) is especially designed for operations on the research aircraft HALO (High Altitude and LOng range research aircraft). HAI permits both, the in-situ measurement of water vapor with an open-path cell and the measurement of total water with an extractive close-path absorption cell. We are using TDLAS (Tunable Diode Laser Absorption Spectroscopy) in two water absorption bands with different line strength to increase the dynamical range. With this concept it is possible to measure from the middle troposphere up to the stratosphere. The open-path cell outside of the fuselage consists of a robust, aerodynamically designed aluminum structure with a single integrated White-cell for both laser beams. Although the mirror separation is only 15cm the cell allows an open absorption path of 4.8m. The detection of higher H2O concentrations is realized with a fiber coupled 1.4µm DFB diode laser. Inside the UTLS layer were small concentrations in the low ppm range are common, we employ up to 20 times stronger fundamental ro-vibration lines of the water molecule near 2.6µm. To supply this, the fiber coupled 2.6µm laser setup was developed and is a part of the HAI. Both detection wavelengths are introduced in the same open path cell via glass fibers which provide water measurements with a minimum of parasitic absorption. We will present the spectrometer design for high-quality airborne water measurements. Furthermore, first laboratory measurements will be shown.

Klostermann, Tim; Afchine, Armin; Barthel, Jochen; Höh, Matthias; Wagner, Steven; Witzel, Oliver; Saathoff, Harald; Schiller, Cornelius; Ebert, Volker

2010-05-01

82

Status of research into lightning effects on aircraft  

NASA Technical Reports Server (NTRS)

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

Plumer, J. A.

1976-01-01

83

Aircraft dose-response research in National Park backcountry areas.  

PubMed

The Federal Aviation Administration and National Park Service conducted joint research to better understand visitor response to noise from commercial air tour operations over units of the National Park System. Dose-response research in National Parks was conducted during the 1990's at heavily visited, frontcountry sites. To expand this work, aircraft dose-response measurements were recently performed at seven backcountry sites in four National Parks. These sites provided both day and overnight hiking and camping opportunities, with visits ranging from one hour to several days. The sampling approach included side-by-side use of three survey instruments, enabling the evaluation of multiple response variables (annoyance, interference with natural quiet, and acceptability) and comparison of audio clip and in situ dose-response, along with the effects of wording and question order. The evaluation of visits longer than previously studied necessitated methodological enhancements including the use of global positioning system based tracking of visitor locations. In total, over 4600 visitor surveys and 50 days of simultaneous acoustic data were collected. This paper, the first of two on this research, describes the research methods and visitor surveys and presents summary results of collected data. PMID:25236022

Rapoza, Amanda; Lewis, Kristin; Aaron, Hastings; Lee, Cynthia

2014-04-01

84

The rotor systems research aircraft: A new step in the technology and rotor system verification cycle  

NASA Technical Reports Server (NTRS)

Rotor systems research aircraft vehicles, (RSRA), were developed specifically to provide the capabilities necessary for the effective and efficient in-flight test and verification of promising new rotor concepts and supporting technology developments. The capabilities of the RSRA aircraft for potential research programs are discussed.

Houston, R. J.; Jenkins, J. L., Jr.; Shipley, J. L.

1978-01-01

85

Short-haul CTOL aircraft research. [on reduced energy for commercial air transportation  

NASA Technical Reports Server (NTRS)

The results of the reduced energy for commercial air transportation studies on air transportation energy efficiency improvement alternatives are reviewed along with subsequent design studies of advanced turboprop powered transport aircraft. The application of this research to short-haul transportation is discussed. The results of several recent turboprop aircraft design are included. The potential fuel savings and cost savings for advanced turboprop aircraft appear substantial, particularly at shorter ranges.

Williams, L. J.

1978-01-01

86

Forced Oscillation Wind Tunnel Testing for FASER Flight Research Aircraft  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

87

NASA Now: Phase Change and Forces of Flight: Aircraft Icing Research  

NASA Video Gallery

Tour the Icing Research Tunnel with Judith VanZante, aeromechanical engineer and icing specialist. VanZante explains the hazards of ice on aircraft, how it is formed, and why the research on ice pl...

88

Subsonic Ultra Green Aircraft Research - Phase II: N+4 Advanced Concept Development.  

National Technical Information Service (NTIS)

This final report documents the work of the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team on Task 1 of the Phase II effort. The team consisted of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, and Georgia Tech....

C. K. Droney, M. K. Bradley

2012-01-01

89

Tiltrotor research aircraft composite blade repairs: Lessons learned  

NASA Technical Reports Server (NTRS)

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

Espinosa, Paul S.; Groepler, David R.

1991-01-01

90

Investigations into the triggered lightning response of the F106B thunderstorm research aircraft  

NASA Technical Reports Server (NTRS)

An investigation has been conducted into the lightning characteristics of the NASA F106B thunderstorm research aircraft. The investigation includes analysis of measured data from the aircraft in the time and frequency domains. Linear and nonlinear computer modelling has also been performed. In addition, new computer tools have been developed, including a new enhanced nonlinear air breakdown model, and a subgrid model useful for analyzing fine details of the aircraft's geometry. Comparison of measured and calculated electromagnetic responses of the aircraft to a triggered lightning environment are presented.

Rudolph, Terence H.; Perala, Rodney A.; Mckenna, Paul M.; Parker, Steven L.

1985-01-01

91

Performance and safety aspects of the XV-15 tilt rotor research aircraft  

NASA Technical Reports Server (NTRS)

Aircraft performance is presented illustrating the flexibility and capability of the XV-15 to conduct its planned proof-of-concept flight research in the areas of dynamics, stability and control, and aerodynamics. Additionally, the aircraft will demonstrate mission-type performance typical of future operational aircraft. The aircraft design is described and discussed with emphasis on the safety and fail-operate features of the aircraft and its systems. Two or more levels of redundancy are provided in the dc and ac electrical systems, hydraulics, conversion, flaps, landing gear extension, SCAS, and force-feel. RPM is maintained by a hydro-electrical blade pitch governor that consists of a primary and standby governor with a cockpit wheel control for manual backup. The two engines are interconnected for operation on a single engine. In the event of total loss of power, the aircraft can enter autorotation starting from the airplane as well as the helicopter mode of flight.

Wernicke, K. G.

1977-01-01

92

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

93

NASA's NB-52B carrier aircraft rolls down a taxiway with the X-43A hypersonic research aircraft and  

NASA Technical Reports Server (NTRS)

NASA's NB-52B carrier aircraft rolls down a taxiway at Edwards Air Force Base with the X-43A hypersonic research aircraft and its modified Pegasus booster rocket slung from a pylon under its right wing. Part of a combined systems test conducted by NASA's Dryden Flight Research Center at Edwards, the taxi test was one of the last major milestones in the Hyper-X research program before the first X-43A flight. The X-43A flights will be the first actual flight tests of an aircraft powered by a revolutionary supersonic-combustion ramjet ('scramjet') engine capable of operating at hypersonic speeds (above Mach 5, or five times the speed of sound). The 12-foot, unpiloted research vehicle was developed and built by MicroCraft Inc., Tullahoma, Tenn., under NASA contract. The booster was built by Orbital Sciences Corp., Dulles, Va.,After being air-launched from NASA's venerable NB-52 mothership, the booster will accelerate the X-43A to test speed and altitude. The X-43A will then separate from the rocket and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it descends into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10, with the first tentatively scheduled for late spring to early summer, 2001.

2001-01-01

94

NASA's NB-52B carrier aircraft rolls down a taxiway with the X-43A hypersonic research aircraft and  

NASA Technical Reports Server (NTRS)

As part of a combined systems test conducted by NASA Dryden Flight Research Center, NASA's NB-52B carrier aircraft rolls down a taxiway at Edwards Air Force Base with the X-43A hypersonic research aircraft and its modified Pegasus booster rocket attached to a pylon under its right wing. The taxi test was one of the last major milestones in the Hyper-X research program before the first X-43A flight. The X-43A flights will be the first actual flight tests of an aircraft powered by a revolutionary supersonic-combustion ramjet ('scramjet') engine capable of operating at hypersonic speeds (above Mach 5, or five times the speed of sound). The 12-foot, unpiloted research vehicle was developed and built by MicroCraft Inc., Tullahoma, Tenn., under NASA contract. The booster was built by Orbital Sciences Corp., Dulles, Va. After being air-launched from NASA's venerable NB-52 mothership, the booster will accelerate the X-43A to test speed and altitude. The X-43A will then separate from the rocket and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it descends into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10.

2001-01-01

95

Overview of STOVL aircraft propulsion research offtakes and vertical lift systems  

NASA Technical Reports Server (NTRS)

The overall Short Takeoff and Vertical Landing (STOVL) Aircraft Propulsion Research program includes key technologies involving offtake systems, vertical lift systems, hot gas ingestion, STOVL augmentors, and integrated flight propulsion controls. A part of the NASA Lewis work involving STOVL aircraft propulsion systems is presented with the emphasis on component-level experiments and analysis related to offtakes and vertical lift systems.

Biesiadny, Thomas J.; Mcardle, Jack G.; Esker, Barbara S.

1993-01-01

96

Research of the military aircraft maintenance support mode based on the prognostics and health management  

Microsoft Academic Search

The paper first introduces the actuality of the maintenance support for domestic military aircrafts. Then, we build the maintenance support system of the military aircraft through the technology of PHM. The system is specified and its impacts on maintenance support under PHM are analyzed, the corresponding maintenance support mode is then researched starting from the four kinds of force of

Deyao Mao; Chuan Lv; Jianming Shi; Yingzhi Zou; Zhiqi Guo

2010-01-01

97

Advanced Research Aircraft to Arrive at Colorado Facility this Week  

NSF Publications Database

... A modified Gulfstream V jet, the aircraft can fly at an altitude of 51,000 feet and has a range of ... s surface with an array of remote sensors Flying through high-forming cirrus clouds to create ...

98

Evaluation of XV-15 tilt rotor aircraft for flying qualities research application  

NASA Technical Reports Server (NTRS)

The results of a design review study and evaluation of the XV-15 Tilt Rotor Research Aircraft for flying qualities research application are presented. The objectives of the program were to determine the capability of the XV-15 aircraft and the V/STOLAND system as a safe, inflight facility to provide meaningful research data on flying qualities, flight control systems, and information display systems.

Radford, R. C.; Schelhorn, A. E.; Siracuse, R. J.; Till, R. D.; Wasserman, R.

1976-01-01

99

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

NASA Technical Reports Server (NTRS)

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

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

1972-01-01

100

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

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

101

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

NASA Technical Reports Server (NTRS)

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

1975-01-01

102

Some flight data extraction techniques used on a general aviation spin research aircraft  

NASA Technical Reports Server (NTRS)

Some methods for obtaining flight data from a highly instrumented general aviation spin research aircraft are developed and illustrated. The required correction terms for the measurement of body accelerations, body velocities, and aircraft orientation are presented. In addition, the equations of motion are utilized to derive total aerodynamic coefficients for comparison with model tests and for analysis. Flight test experience is used to evaluate the utility of various instruments and calculation techniques for spin research.

Sliwa, S. M.

1979-01-01

103

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

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

104

A study for active control research and validation using the Total In-Flight Simulator (TIFS) aircraft  

NASA Technical Reports Server (NTRS)

The results of a feasibility study and preliminary design for active control research and validation using the Total In-Flight Simulator (TIFS) aircraft are documented. Active control functions which can be demonstrated on the TIFS aircraft and the cost of preparing, equipping, and operating the TIFS aircraft for active control technology development are determined. It is shown that the TIFS aircraft is as a suitable test bed for inflight research and validation of many ACT concepts.

Chen, R. T. N.; Daughaday, H.; Andrisani, D., II; Till, R. D.; Weingarten, N. C.

1975-01-01

105

Overview of the Light Aircraft Aerosol Research Inlet (LAARI)  

Microsoft Academic Search

Aircraft provide a mobile platform for measuring vertical profile aerosol properties. The efficacy of these measurements, however, is constrained by the aerosol inlet sampling efficiency. Larger particles are often lost to turbulent deposition and impaction inside the inlet and sampling lines, respectively. This precludes the measurement of coarse mode particles, important to visibility and radiative transfer studies. Turbulent deposition of

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

2004-01-01

106

The Use of Aircraft in Air Pollution Research  

Microsoft Academic Search

An instrumented single engine aircraft is being used to characterize plumes from large emission sources. By cross sectioning these plumes at a number of points we hope to describe the character and concentration of pollution as it ages and travels downwind under known meteorological conditions. This paper reports experimental work thus far completed on aerosol measurement. Flights have been made

Roy O. McCaldin; Louis W. Johnson

1969-01-01

107

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

NASA Technical Reports Server (NTRS)

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

Navarro, Robert

2007-01-01

108

Resilient Propulsion Control Research for the NASA Integrated Resilient Aircraft Control (IRAC) Project  

NASA Technical Reports Server (NTRS)

Gas turbine engines are designed to provide sufficient safety margins to guarantee robust operation with an exceptionally long life. However, engine performance requirements may be drastically altered during abnormal flight conditions or emergency maneuvers. In some situations, the conservative design of the engine control system may not be in the best interest of overall aircraft safety; it may be advantageous to "sacrifice" the engine to "save" the aircraft. Motivated by this opportunity, the NASA Aviation Safety Program is conducting resilient propulsion research aimed at developing adaptive engine control methodologies to operate the engine beyond the normal domain for emergency operations to maximize the possibility of safely landing the damaged aircraft. Previous research studies and field incident reports show that the propulsion system can be an effective tool to help control and eventually land a damaged aircraft. Building upon the flight-proven Propulsion Controlled Aircraft (PCA) experience, this area of research will focus on how engine control systems can improve aircraft safe-landing probabilities under adverse conditions. This paper describes the proposed research topics in Engine System Requirements, Engine Modeling and Simulation, Engine Enhancement Research, Operational Risk Analysis and Modeling, and Integrated Flight and Propulsion Controller Designs that support the overall goal.

Guo, Ten-Huei; Litt, Jonathan S.

2007-01-01

109

Research on hypersonic aircraft using pre-cooled turbojet engines  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

110

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

NASA Technical Reports Server (NTRS)

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.

1996-01-01

111

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

NASA Technical Reports Server (NTRS)

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. More taxi and radio frequency tests were slated before it's first flight would be made. This took place on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of just over 10 feet. A Williams International F112 turbofan engine provided close to 700 pounds of thrust. A typical research flight lasted 35 to 45 minutes from takeoff to touchdown. A total of 31 successful research flights were flown from May 17, 1997, to November 12, 1997, amassing 15 hours and 38 minutes of flight time. The aircraft reached an altitude of 20,200 feet and a maximum angle of attack of 40 degrees. In a follow-on effort, the Air Force Research Laboratory (AFRL), Wright-Patterson Air Force Base, Ohio, contracted with Boeing to fly AFRL's Reconfigurable Control for Tailless Fighter Aircraft (RESTORE) software as a demonstration of the adaptability of the neural-net algorithm to compensate for in-flight damage or malfunction of effectors, such as flaps, ailerons and rudders. Two RESTORE research flights were flown in December 1998, proving the viability of the software approach. The X-36 aircraft flown at the Dryden Flight Research Center in 1997 was a 28-percent scale representation of a theoretical advanced fighter aircraft. The Boeing Phantom Works (formerly McDonnell Douglas) in St. Louis, Missouri, built two of the vehicles in a cooperative agreement with the Ames Research Center, Moffett Field, California.

1996-01-01

112

Aircraft ground vibration testing at NASA Ames-Dryden Flight Research Facility  

NASA Technical Reports Server (NTRS)

At the NASA Ames Research Center's Dryden Flight Research Facility at Edwards Air Force Base, California, a variety of ground vibration test techniques has been applied to an assortment of new or modified aerospace research vehicles. This paper presents a summary of these techniques and the experience gained from various applications. The role of ground vibration testing in the qualification of new and modified aircraft for flight is discussed. Data are presented for a wide variety of aircraft and component tests, including comparisons of sine-dwell, single-input random, and multiple-input random excitation methods on a JetStar airplane.

Kehoe, Michael W.

1987-01-01

113

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

NASA Technical Reports Server (NTRS)

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

Linden, A. W.

1972-01-01

114

NASA/Army Rotorcraft Technology. Volume 3: Systems Integration, Research Aircraft, and Industry  

NASA Technical Reports Server (NTRS)

This is part 3 of the conference proceedings on rotorcraft technology. This volume is divided into areas on systems integration, research aircraft, and industry. Representative titles from each area are: system analysis in rotorcraft design, the past decade; rotorcraft flight research with emphasis on rotor systems; and an overview of key technology thrusts at Bell Helicopter Textron.

1988-01-01

115

Military aircraft and missile technology at the Langley Research Center: A selected bibliography  

NASA Technical Reports Server (NTRS)

A compilation of reference material is presented on the Langley Research Center's efforts in developing advanced military aircraft and missile technology over the past twenty years. Reference material includes research made in aerodynamics, performance, stability, control, stall-spin, propulsion integration, flutter, materials, and structures.

Maddalon, D. V.

1980-01-01

116

Comparison of model and flight test data for an augmented jet flap STOL research aircraft  

NASA Technical Reports Server (NTRS)

Aerodynamic design data for the Augmented Jet Flap STOL Research Aircraft or commonly known as the Augmentor-Wing Jet-STOL Research Aircraft was based on results of tests carried out on a large scale research model in the NASA Ames 40- by 80-Foot Wind Tunnel. Since the model differs in some respects from the aircraft, precise correlation between tunnel and flight test is not expected, however the major areas of confidence derived from the wind tunnel tests are delineated, and for the most part, tunnel results compare favorably with flight experience. In some areas the model tests were known to be nonrepresentative so that a degree of uncertainty remained: these areas of greater uncertainty are identified, and discussed in the light of subsequent flight tests.

Cook, W. L.; Whittley, D. C.

1975-01-01

117

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

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

118

Subsonic Ultra Green Aircraft Research Phase II: N+4 Advanced Concept Development  

NASA Technical Reports Server (NTRS)

This final report documents the work of the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team on Task 1 of the Phase II effort. The team consisted of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, and Georgia Tech. Using a quantitative workshop process, the following technologies, appropriate to aircraft operational in the N+4 2040 timeframe, were identified: Liquefied Natural Gas (LNG), Hydrogen, fuel cell hybrids, battery electric hybrids, Low Energy Nuclear (LENR), boundary layer ingestion propulsion (BLI), unducted fans and advanced propellers, and combinations. Technology development plans were developed.

Bradley, Marty K.; Droney, Christopher K.

2012-01-01

119

Satellite communications provisions on NASA Ames instrumented aircraft platforms for Earth science research/applications  

NASA Technical Reports Server (NTRS)

Earth science activities at NASA Ames are research in atmospheric and ecosystem science, development of remote sensing and in situ sampling instruments, and their integration into scientific research platform aircraft. The use of satellite communications can greatly extend the capability of these agency research platform aircraft. Current projects and plans involve satellite links on the Perseus UAV and the ER-2 via TDRSS and a proposed experiment on the NASA Advanced Communications Technology Satellite. Provisions for data links on the Perseus research platform, via TDRSS S-band multiple access service, have been developed and are being tested. Test flights at Dryden are planned to demonstrate successful end-to-end data transfer. A Unisys Corp. airborne satcom STARLink system is being integrated into an Ames ER-2 aircraft. This equipment will support multiple data rates up to 43 Mb/s each via the TDRS S Ku-band single access service. The first flight mission for this high-rate link is planned for August 1995. Ames and JPL have proposed an ACTS experiment to use real-time satellite communications to improve wildfire research campaigns. Researchers and fire management teams making use of instrumented aircraft platforms at a prescribed burn site will be able to communicate with experts at Ames, the U.S. Forest Service, and emergency response agencies.

Shameson, L.; Brass, J. A.; Hanratty, J. J.; Roberts, A. C.; Wegener, S. S.

1995-01-01

120

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

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

121

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

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

122

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

123

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

124

Application of a cost/performance measurement system on a research aircraft project  

NASA Technical Reports Server (NTRS)

The fundamentals of the cost/performance management system used in the procurement of two tilt rotor aircraft for a joint NASA/Army research project are discussed. The contractor's reporting system and the GPO's analyses are examined. The use of this type of reporting system is assessed. Recommendations concerning the use of like systems on future projects are included.

Diehl, J. J.

1978-01-01

125

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

NASA Technical Reports Server (NTRS)

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

Feuillebois, P.; Scibilia, M. F.

1983-01-01

126

Aircrew-aircraft integration: A summary of US Army research programs and plans  

NASA Technical Reports Server (NTRS)

A review of selected programs which illustrate the research efforts of the U.S. Army Aeromechanics Laboratory in the area of aircrew-aircraft integration is presented. Plans for research programs to support the development of future military rotorcraft are also described. The crew of a combat helicopter must, in general, perform two major functions during the conduct of a particular mission: flightpath control and mission management. Accordingly, the research programs described are being conducted in the same two major categories: (1) flightpath control, which encompasses the areas of handling qualities, stability and control, and displays for the pilot's control of the rotorcraft's flightpath, and (2) mission management, which includes human factors and cockpit integration research topics related to performance of navigation, communication, and aircraft systems management tasks.

Key, D. L.; Aiken, E. W.

1984-01-01

127

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

NASA Technical Reports Server (NTRS)

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

1995-01-01

128

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

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

129

The NASA Dryden Flight Research Center Unmanned Aircraft System Service Capabilities  

NASA Technical Reports Server (NTRS)

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

Bauer, Jeff

2007-01-01

130

The NASA Dryden Flight Research Center Unmanned Aircraft System Service Capabilities  

NASA Technical Reports Server (NTRS)

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

Bauer, Jeff

2007-01-01

131

Aircraft ground vibration testing at the NASA Dryden Flight Research Facility, 1993  

NASA Technical Reports Server (NTRS)

The NASA Dryden Flight Research Facility performs ground vibration testing to assess the structural characteristics of new and modified research vehicles. This paper updates the research activities, techniques used, and experiences in applying this technology to aircraft since 1987. Test equipment, data analysis methods, and test procedures used for typical test programs are discussed. The data presented illustrate the use of modal test and analysis in flight research programs for a variety of aircraft. This includes a technique to acquire control surface free-play measurements on the X-31 airplane more efficiently, and to assess the effects of structural modifications on the modal characteristics of an F-18 aircraft. In addition, the status and results from current research activities are presented. These data show the effectiveness of the discrete modal filter as a preprocessor to uncouple response measurements into simple single-degree-of-freedom responses, a database for the comparison of different excitation methods on a JetStar airplane, and the effect of heating on modal frequency and damping.

Kehoe, Michael W.; Freudinger, Lawrence C.

1994-01-01

132

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

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

133

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

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

134

Supersonic cruise research aircraft structural studies: Methods and results  

NASA Technical Reports Server (NTRS)

NASA Langley Research Center SCAR in-house structural studies are reviewed. In methods development, advances include a new system of integrated computer programs called ISSYS, progress in determining aerodynamic loads and aerodynamically induced structural loads (including those due to gusts), flutter optimization for composite and metal airframe configurations using refined and simplified mathematical models, and synthesis of active controls. Results given address several aspects of various SCR configurations. These results include flutter penalties on composite wing, flutter suppression using active controls, roll control effectiveness, wing tip ground clearance, tail size effect on flutter, engine weight and mass distribution influence on flutter, and strength and flutter optimization of new configurations. The ISSYS system of integrated programs performed well in all the applications illustrated by the results, the diversity of which attests to ISSYS' versatility.

Sobieszczanski-Sobieski, J.; Gross, D.; Kurtze, W.; Newsom, J.; Wrenn, G.; Greene, W.

1981-01-01

135

Specially equipped aircraft used in Florida airborne field mill research  

NASA Technical Reports Server (NTRS)

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

2000-01-01

136

Concept to Reality: Contributions of the Langley Research Center to US Civil Aircraft of the 1990s  

NASA Technical Reports Server (NTRS)

This document is intended to be a companion to NASA SP-2000-4519, 'Partners in Freedom: Contributions of the Langley Research Center to U.S. Military Aircraft of the 1990s'. Material included in the combined set of volumes provides informative and significant examples of the impact of Langley's research on U.S. civil and military aircraft of the 1990s. This volume, 'Concept to Reality: Contributions of the NASA Langley Research Center to U.S. Civil Aircraft of the 1990s', highlights significant Langley contributions to safety, cruise performance, takeoff and landing capabilities, structural integrity, crashworthiness, flight deck technologies, pilot-vehicle interfaces, flight characteristics, stall and spin behavior, computational design methods, and other challenging technical areas for civil aviation. The contents of this volume include descriptions of some of the more important applications of Langley research to current civil fixed-wing aircraft (rotary-wing aircraft are not included), including commercial airliners, business aircraft, and small personal-owner aircraft. In addition to discussions of specific aircraft applications, the document also covers contributions of Langley research to the operation of civil aircraft, which includes operating problems. This document is organized according to disciplinary technologies, for example, aerodynamics, structures, materials, and flight systems. Within each discussion, examples are cited where industry applied Langley technologies to specific aircraft that were in operational service during the 1990s and the early years of the new millennium. This document is intended to serve as a key reference for national policy makers, internal NASA policy makers, Congressional committees, the media, and the general public. Therefore, it has been written for a broad general audience and does not presume any significant technical expertise. An extensive bibliography is provided for technical specialists and others who desire a more indepth discussion of the contributions.

Chambers, Joseph R.

2003-01-01

137

Bibliography of Supersonic Cruise Aircraft Research (SCAR) Program from 1972 to Mid-1977  

NASA Technical Reports Server (NTRS)

This bibliography documents publications of the supersonic cruise aircraft research (SCAR) program that were generated during the first 5 years of effort. The reports are arranged according to systems studies and five SCAR disciplines: propulsion, stratospheric emissions impact, structures and materials, aerodynamic performance, and stability and control. The specific objectives of each discipline are summarized. Annotation is included for all NASA inhouse and low-number contractor reports. There are 444 papers and articles included.

Hoffman, S.

1977-01-01

138

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

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

139

Research in Military Aircraft Emissions Photo of a B-52 bomber taking  

E-print Network

) · Focus on high-payload aircraft · Aircraft emissions play a significant role in atmospheric pollution local to global scale. Most of the aircraft fuel consumed by the Air Force is in high-payload aircraft reliable means for quantitative determination of aircraft emissions at the present. Contact: Meng-Dawn

140

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

141

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

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

142

Experimental Aerodynamic Characteristics of a Joined-wing Research Aircraft Configuration  

NASA Technical Reports Server (NTRS)

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

Smith, Stephen C.; Stonum, Ronald K.

1989-01-01

143

Atmospheric effects of stratospheric aircraft - A status report from NASA's High-Speed Research Program  

NASA Technical Reports Server (NTRS)

Studies have indicated that, with sufficient technology development, future high-speed civil transport aircraft could be economically competitive with long-haul subsonic aircraft. However, uncertainty about atmospheric pollution, along with community noise and sonic boom, continues to be a major concern which is being addressed in the planned six-year High-Speed Research Program begun in 1990. Building on NASA's research in atmospheric science and emissions reduction, current analytical predictions indicate that an operating range may exist at altitudes below 20 km (i.e., corresponding to a cruise Mach number of approximately 2.4) where the goal level of 5 gm equivalent NO2 emissions/kg fuel will deplete less than one percent of column ozone. Because it will not be possible to directly measure the impact of an aircraft fleet on the atmosphere, the only means of assessment will be prediction. The process of establishing credibility for the predicted effects will likely be complex and involve continued model development and testing against climatological patterns. In particular, laboratory simulation of heterogeneous chemistry and other effects, and direct measurements of well understood tracers in the troposphere and stratosphere are being used to improve the current models.

Wesoky, Howard L.; Prather, Michael J.

1991-01-01

144

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

145

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

146

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

NASA Astrophysics Data System (ADS)

Geometric altitude data from a combined Global Navigation Satellite System (GNSS) and inertial measurement unit (IMU) system on the University of Wyoming King Air research aircraft are used to estimate acceleration effects on static pressure measurement. Using data collected during periods of accelerated flight, comparison of measured pressure with that derived from GNSS/IMU geometric altitude show that errors exceeding 150 Pa can occur which is significant in airspeed and atmospheric air motion determination. A method is developed to predict static pressure errors from analysis of differential pressure measurements from a Rosemount model 858 differential pressure air velocity probe. The method was evaluated with a carefully designed probe towed on connecting tubing behind the aircraft - a "trailing cone" - in steady flight, and shown to have a precision of about ±10 Pa over a wide range of conditions including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, compared to the GNSS/IMU data, this algorithm predicts corrections to a precision of better than ±20 Pa. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are examined.

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

2012-05-01

147

Fabrication methods for YF-12 wing panels for the Supersonic Cruise Aircraft Research Program  

NASA Technical Reports Server (NTRS)

Advanced fabrication and joining processes for titanium and composite materials are being investigated by NASA to develop technology for the Supersonic Cruise Aircraft Research (SCAR) Program. With Lockheed-ADP as the prime contractor, full-scale structural panels are being designed and fabricated to replace an existing integrally stiffened shear panel on the upper wing surface of the NASA YF-12 aircraft. The program involves ground testing and Mach 3 flight testing of full-scale structural panels and laboratory testing of representative structural element specimens. Fabrication methods and test results for weldbrazed and Rohrbond titanium panels are discussed. The fabrication methods being developed for boron/aluminum, Borsic/aluminum, and graphite/polyimide panels are also presented.

Hoffman, E. L.; Payne, L.; Carter, A. L.

1975-01-01

148

Capabilities Enhanced for Researching the Reduction of Emissions in Future Aircraft  

NASA Technical Reports Server (NTRS)

Aircraft future aircraft jet engines will run at higher pressures to obtain greater fuel efficiency and performance. This will require new combustor designs to keep the nitrogen oxide and carbon monoxide emissions at environmentally acceptable levels. The actual pressures and temperatures found in gas turbine combustors must be duplicated in a laboratory to verify the emissions characteristics of gas turbine engines. Recognizing this, the U.S. aircraft gas turbine industry identified a need for a national facility that could duplicate the severe inlet conditions of future combustors. Because of our expertise in combustion emissions reduction research and in the design and operation of high-pressure test facilities, the NASA Lewis Research Center was seen as the natural location for such a facility. As a national laboratory, Lewis could provide these facilities to all U.S. gas turbine engine manufacturers while protecting their proprietary interests. Called the Advanced Subsonic Combustion Rig, the facility will provide up to 60-atm pressures at inlet temperatures up to 1300 F and air flow rates up to 38 lb/sec. Furthermore, it will offer state-of-the-art diagnostic methods for characterizing advanced combustor concepts. Aeronautical combustion research at Lewis provided several significant accomplishments recently in support of both the High Speed Research (HSR) and Advanced Subsonic Technology (AST) programs. For example, in the High Speed Research Program, NO_x reductions of up to 90 percent were achieved in prototype combustor hardware. Advanced computational analysis, gas sampling, and laser diagnostic techniques were critical to this success. Working closely with the gas turbine industry, we have successfully transferred this low-emissions combustor technology into engine prototype hardware. This hardware is now being tested at the engine manufacturers facilities. Complementary tests in Lewis currently available 30-atm test facilities are also underway, taking advantage of Lewis unique diagnostic capabilities. By utilizing test facilities belonging to both NASA and its industry partners, we have tested multiple combustor concepts in a shorter period of time.

1995-01-01

149

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

NASA Technical Reports Server (NTRS)

Established in 1917 as the nation#s first civil aeronautics research laboratory under the National Advisory Commit-tee for Aeronautics (NACA), Langley was a small laboratory that solved the problems of flight for military and civil aviation. Throughout history, Langley has maintained a working partnership with the Department of Defense, U.S. industry, universities, and other government agencies to support the defense of the nation with research. During World War II, Langley directed virtually all of its workforce and facilities to research for military aircraft. Following the war, a balanced program of military and civil projects was undertaken. In some instances Langley research from one aircraft program helped solve a problem in another. At the conclusion of some programs, Langley obtained the research models for additional tests to learn more about previously unknown phenomena. The data also proved useful in later developmental programs. Many of the military aircraft in the U.S. inventory as of late 1999 were over 20 years old. Langley activities that contributed to the development of some of these aircraft began over 50 years prior. This publication documents the role, from early concept stages to problem solving for fleet aircraft, that Langley played in the military aircraft fleet of the United States for the 1990's.

Chambers, Joseph R.

2000-01-01

150

Research on aircraft trailing vortex detection based on laser's multiplex information echo  

NASA Astrophysics Data System (ADS)

Airfoil trailing vortex is an important reason for the crash, and vortex detection is the basic premise for the civil aeronautics boards to make the flight measures and protect civil aviation's security. So a new method of aircraft trailing vortex detection based on laser's multiplex information echo has been proposed in this paper. According to the classical aerodynamics theories, the formation mechanism of the trailing vortex from the airfoil wingtip has been analyzed, and the vortex model of Boeing 737 in the taking-off phase has also been established on the FLUENT software platform. Combining with the unique morphological structure characteristics of trailing vortex, we have discussed the vortex's possible impact on the frequency, amplitude and phase information of laser echo, and expounded the principle of detecting vortex based on fusing this information variation of laser echo. In order to prove the feasibility of this detecting technique, the field experiment of detecting the vortex of civil Boeing 737 by laser has been carried on. The experimental result has shown that the aircraft vortex could be found really in the laser scanning area, and its diffusion characteristic has been very similar to the previous simulation result. Therefore, this vortex detection means based on laser's multiplex information echo was proved to be practicable relatively in this paper. It will provide the detection and identification of aircraft's trailing vortex a new way, and have massive research value and extensive application prospect as well.

Zhao, Nan-xiang; Wu, Yong-hua; Hu, Yi-hua; Lei, Wu-hu

2010-10-01

151

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

152

Carrier aircraft  

NASA Technical Reports Server (NTRS)

The Ohio State University planned to conduct a conceptual design of a single research vehicle that could be used to explore the flight regime from Mach 6 to Mach 12. Since this aircraft will be a special purpose vehicle, it need not take off and land in a conventional manner. Indeed, if this aircraft were launched from a larger aircraft that carried it to altitude, then conventional landing gear would not be needed and the extra weight of the fuel needed to take off and climb into the stratosphere would be eliminated. The focus of the students' project was on the design of a carrier aircraft answering to the specifications. Its mission is to take off with the research aircraft from runways of less than 15,000 feet, climb to 40,000 feet, and release the hypersonic aircraft at the speed of Mach 8, and return to base. The range of this mission is 2000 n.m. This study includes the conception of an optimized aircraft (geometry, weights, propulsion, aerodynamics, interactions between the two aircraft, etc.), the longitudinal stability of the composite, and the separation critical phase.

1990-01-01

153

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

NASA Astrophysics Data System (ADS)

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

Wildmann, Norman; Bange, Jens

2014-05-01

154

V/STOL Systems Research Aircraft: A Tool for Cockpit Integration  

NASA Technical Reports Server (NTRS)

The next generation ASTOVL aircraft will have a complicated propulsion System. The configuration choices include Direct Lift, Lift-Fan and Lift+Lift /Cruise but the aircraft must also have supersonic performance and low-observable characteristics. The propulsion system may have features such as flow blockers, vectoring nozzles and flow transfer schemes. The flight control system will necessarily fully integrate the aerodynamic surfaces and the propulsive elements. With a fully integrated, fly-by-wire flight/propulsion control system, the options for cockpit integration are interesting and varied. It is possible to decouple longitudinal and vertical responses allowing the pilot to close the loop on flight path and flight path acceleration directly. In the hover, the pilot can control the translational rate directly without having to stabilize the inner rate and attitude loops. The benefit of this approach, reduced workload and increased precision. has previously been demonstrated through several motion-based simulations. In order to prove the results in flight, the V/STOL System Research Aircraft (VSRA) was developed at the NASA Ames Research Center. The VSRA is the YAV-8B Prototype modified with a research flight control system using a series-parallel servo configuration in all the longitudinal degrees of freedom (including thrust and thrust vector angle) to provide an integrated flight and propulsion control system in a limited envelope. Development of the system has been completed and flight evaluations of the response types have been performed. In this paper we will discuss the development of the VSRA, the evolution of the flight path command and translational rate command response types and the Guest Pilot evaluations of the system. Pilot evaluation results will be used to draw conclusions regarding the suitability of the system to satisfy V/STOL requirements.

Stortz, Michael W.; ODonoghue, Dennis P.; Tiffany, Geary (Technical Monitor)

1995-01-01

155

V/STOL systems research aircraft: A tool for cockpit integration  

NASA Technical Reports Server (NTRS)

The next generation ASTOVL aircraft will have a complicated propulsion system. The configuration choices include Direct Lift, Lift-Fan and Lift + Lift/Cruise but the aircraft must also have supersonic performance and low-observable characteristics. The propulsion system may have features such as flow blockers, vectoring nozzles and flow transfer schemes. The flight control system will necessarily fully integrate the aerodynamic surfaces and the propulsive elements. With a fully integrated, fly-by-wire flight/propulsion control system, the options for cockpit integration are interesting and varied. It is possible to de-couple longitudinal and vertical responses allowing the pilot to close the loop on flightpath and flightpath acceleration directly. In the hover, the pilot can control the translational rate directly without having to stabilize the inner rate and attitude loops. The benefit of this approach, reduced workload and increased precision, has previously been demonstrated through several motion-based simulations. In order to prove the results in flight, the V/STOL System Research Aircraft (VSRA) was developed at the NASA Ames Research Center. The VSRA is the YAV-8B Prototype modified with a research flight control system using a series-parallel servo configuration in all the longitudinal degrees of freedom (including thrust and thrust vector angle) to provide an integrated flight and propulsion control system in a limited envelope. Development of the system has been completed and flight evaluations of the response types have been performed. In this paper we will discuss the development of the VSRA, the evolution of the flightpath command and translational rate command response types and the Guest Pilot evaluations of the system. Pilot evaluation results are used to draw conclusions regarding the suitability of the system to satisfy V/STOL requirements.

Stortz, Michael W.; ODonoghue, Dennis P.

1995-01-01

156

Advancement of proprotor technology. Task 1: Design study summary. [aerodynamic concept of minimum size tilt proprotor research aircraft  

NASA Technical Reports Server (NTRS)

A tilt-proprotor proof-of-concept aircraft design study has been conducted. The results are presented. The ojective of the contract is to advance the state of proprotor technology through design studies and full-scale wind-tunnel tests. The specific objective is to conduct preliminary design studies to define a minimum-size tilt-proprotor research aircraft that can perform proof-of-concept flight research. The aircraft that results from these studies is a twin-engine, high-wing aircraft with 25-foot, three-bladed tilt proprotors mounted on pylons at the wingtips. Each pylon houses a Pratt and Whitney PT6C-40 engine with a takeoff rating of 1150 horsepower. Empty weight is estimated at 6876 pounds. The normal gross weight is 9500 pounds, and the maximum gross weight is 12,400 pounds.

1969-01-01

157

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

158

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

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

159

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

160

An experimental and analytical method for approximate determination of the tilt rotor research aircraft rotor/wing download  

NASA Technical Reports Server (NTRS)

The XV-15 Tilt Rotor Research Aircraft download phenomenon was analyzed. This phenomenon is a direct result of the two rotor wakes impinging on the wing upper surface when the aircraft is in the hover configuration. For this study the analysis proceeded along tow lines. First was a method whereby results from actual hover tests of the XV-15 aircraft were combined with drag coefficient results from wind tunnel tests of a wing that was representative of the aircraft wing. Second, an analytical method was used that modeled that airflow caused gy the two rotors. Formulas were developed in such a way that acomputer program could be used to calculate the axial velocities were then used in conjunction with the aforementioned wind tunnel drag coefficinet results to produce download values. An attempt was made to validate the analytical results by modeling a model rotor system for which direct download values were determinrd..

Jordon, D. E.; Patterson, W.; Sandlin, D. R.

1985-01-01

161

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

162

Enabling Electric Propulsion for Flight - Hybrid Electric Aircraft Research at AFRC  

NASA Technical Reports Server (NTRS)

Advances in electric machine efficiency and energy storage capability are enabling a new alternative to traditional propulsion systems for aircraft. This has already begun with several small concept and demonstration vehicles, and NASA projects this technology will be essential to meet energy and emissions goals for commercial aviation in the next 30 years. In order to raise the Technology Readiness Level of electric propulsion systems, practical integration and performance challenges will need to be identified and studied in the near-term so that larger, more advanced electric propulsion system testbeds can be designed and built. Researchers at NASA Armstrong Flight Research Center are building up a suite of test articles for the development, integration, and validation of these systems in a real world environment.

Clarke, Sean; Lin, Yohan; Kloesel, Kurt; Ginn, Starr

2014-01-01

163

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

NASA Technical Reports Server (NTRS)

Two candidate control systems for the Vertical/Short Takeoff and Landing (V/STOL) Research Aircraft (VSRA) are described, both of which are limited-authority, digital, fly-by wire variants of the original YAV-8B Harrier control system. The performance of these systems was compared with that of an ideal, full-authority system in simulated, adverse-weather V/STOL shipboard operations using the Ames Research Center's Vertical Motion Simulator. Both systems showed some performance degradation relative to the ideal, but both were adequate to meet VSRA program objectives. The favored system, selected because of safety considerations, was further simulated using a precision visual hovering task that verified its acceptability.

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

1987-01-01

164

Sikorsky UH-60 (USA 82-23748 NASA-748) Air-loads research aircraft - Blackhawk helicopter with  

NASA Technical Reports Server (NTRS)

Sikorsky UH-60 (USA 82-23748 NASA-748) Air-loads research aircraft - Blackhawk helicopter with MUX-Bucket in flight Note: Used in publication in Flight Research at Ames; 57 Years of Development and Validation of Aeronautical Technology NASA SP-1998-3300 fig. 135

1993-01-01

165

Advanced turboprop aircraft noise annoyance - A review of recent NASA research  

Microsoft Academic Search

Passenger and community response to advanced turboprop aircraft noise are studied. Four experiments were conducted utilizing an aircraft noise synthesis system, an exterior effects room, an anechoic listening room, and a Space Station\\/aircraft acoustic apparatus; the experimental conditions and procedures for the psychoacoustic studies are described. The community noise studies involved evaluating the effects of various tonal characteristics on annoyance.

D. A. McCurdy; J. D. Leatherwood; K. P. Shepherd

1986-01-01

166

Research on optimization model of civil aircraft spare parts inventory allocation  

Microsoft Academic Search

According to the engineering practice of civil aircraft spare parts management, in terms of maximize of the service level of civil aircraft spare part and make the inventory of each item reach an excellent level, a model was presented to optimize the aircraft average waiting time, which took the total spare part provision cost as constraint. A heuristic algorithm is

Ni Xiancun; Zuo Hongfu; Liu Ming

2008-01-01

167

Sensor Web Approach For Next-Generation Research Aircraft Platform Data Systems  

NASA Astrophysics Data System (ADS)

A NASA project creating sensor web tools has resulted in systems which provide network telemetry for airborne experiments, while also providing traditional data system functions. The Research Environment for Vehicle-Embedded Analysis on Linux (REVEAL) software and hardware has now been tested on many Airborne Science campaigns and on several aircraft platforms, both manned and UAV, with participants across the Internet monitoring and contributing to the success of each mission. The software is a self-configuring, self-documenting framework based on open-standards XML which can wrap any schema such as SensorML to automatically generate metadata. Experimenters can participate by providing real-time instrument data in whatever format is most convenient to them. Buffering middleware enables efficient data distribution across the network, where applications can add value and create live displays, despite very limited air-ground bandwidth for telemetering the merged data streams. The system architecture is described, and plans are described to replace or install systems on several NASA Airborne Science platform aircraft. These new systems will be transparent to legacy instruments while enabling sensor web and telepresence applications, and provide a common interface across the platforms.

Sorenson, C.; Freudinger, L.; Yarbrough, S.

2006-12-01

168

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

NASA Technical Reports Server (NTRS)

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

1995-01-01

169

Static aeroelastic analysis of a three-dimensional generic wing  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

170

Aircraft Cabin Environmental Quality Sensors  

E-print Network

commercial aircraft, for which the minimum cabin pressure isAircraft cabin environment Airliner cabin environmental research American National Standards Institute pressure:and cabin P. The FAA also requires that aircraft maintain air pressures

Gundel, Lara

2010-01-01

171

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

172

The flight test program for the hydrogen powered NASP/X-30 research aircraft  

NASA Technical Reports Server (NTRS)

The NASP/X-30 will be the first U.S. manned aircraft to be powered with hydrogen. Flight testing the X-30 powered with liquid and/or slush hydrogen along with its high speed capability will present unique challenges to the flight test community. The paper describes the overall X-30 flight research program along with some of the key technology challenges. A flight test envelope expansion concept is described along with typical mission profiles. Flight test problems unique to this class of vehicle will be outlined as well as some preliminary thoughts as to solutions to those problems. The X-30 ground operations with hydrogen must be compatible with the normal operations at the flight test site. A concept for the ground support system will be introduced.

Wierzbanowski, Theodore; Armstrong, Johnny G.

1991-01-01

173

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

NASA Technical Reports Server (NTRS)

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

Jordan, F. L., Jr.

1980-01-01

174

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

175

Development and system identification of a light unmanned aircraft for flying qualities research  

SciTech Connect

This paper describes the design, construction, flight testing and system identification of a light weight remotely piloted aircraft and its use in studying flying qualities in the longitudinal axis. The short period approximation to the longitudinal dynamics of the aircraft was used. Parameters in this model were determined a priori using various empirical estimators. These parameters were then estimated from flight data using a maximum likelihood parameter identification method. A comparison of the parameter values revealed that the stability derivatives obtained from the empirical estimators were reasonably close to the flight test results. However, the control derivatives determined by the empirical estimators were too large by a factor of two. The aircraft was also flown to determine how the longitudinal flying qualities of light weight remotely piloted aircraft compared to full size manned aircraft. It was shown that light weight remotely piloted aircraft require much faster short period dynamics to achieve level I flying qualities in an up-and-away flight task.

Peters, M.E.; Andrisani, D. II

1994-12-31

176

NASA/USRA high altitude research aircraft. Gryphon: Soar like an eagle with the roar of a lion  

NASA Technical Reports Server (NTRS)

At the equator, the ozone layer ranges from 65,000 to 130,000+ feet. This is beyond the capabilities of the ER-2, which is NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozoned layer at the equator. This aircraft must be able to satisfy four mission profiles. Mission one is a polar mission which ranges from Chile to the South Pole and back to Chile, a total range of 6000 n. mi. at 100,000 feet with a 2500 lb. payload. The second mission is also a polar mission with a decreased altitude of 70,000 feet and an increased payload of 4000 lb. For the third mission, the aircraft will take-off at NASA Ames, cruise at 100,000 feet carrying a 2500 lb. payload, and land in Puerto Montt, Chile. The final mission requires the aircraft to take-off at NASA Ames, cruise at 100,000 feet with a 1000 lb. payload, make an excursion to 120,000 feet, and land at Howard AFB, Panama. All three missions require that a subsonic Mach number be maintained due to constraints imposed by the air sampling equipment. The aircraft need not be manned for all four missions. Three aircraft configurations were determined to be the most suitable for meeting the above requirements. The performance of each configuration is analyzed to investigate the feasibility of the project requirements. In the event that a requirement can not be obtained within the given constraints, recommendations for proposal modifications are given.

Rivera, Jose; Nunes, Anne; Mcray, Mike; Wong, Walter; Ong, Audrey; Coble, Scott

1991-01-01

177

Advanced Technology Blade testing on the XV-15 Tilt Rotor Research Aircraft  

NASA Technical Reports Server (NTRS)

The XV-15 Tilt Rotor Research Aircraft has just completed the first series of flight tests with the Advanced Technology Blade (ATB) rotor system. The ATB are designed specifically for flight research and provide the ability to alter blade sweep and tip shape. A number of problems were encountered from first installation through envelope expansion to airplane mode flight that required innovative solutions to establish a suitable flight envelope. Prior to operation, the blade retention hardware had to be requalified to a higher rated centrifugal load, because the blade weight was higher than expected. Early flights in the helicopter mode revealed unacceptably high vibratory control system loads which required a temporary modification of the rotor controls to achieve higher speed flight and conversion to airplane mode. The airspeed in airplane mode was limited, however, because of large static control loads. Furthermore, analyses based on refined ATB blade mass and inertia properties indicated a previously unknown high-speed blade mode instability, also requiring airplane-mode maximum airspeed to be restricted. Most recently, a structural failure of an ATB cuff (root fairing) assembly retention structure required a redesign of the assembly. All problems have been addressed and satisfactory solutions have been found to allow continued productive flight research of the emerging tilt rotor concept.

Wellman, Brent

1992-01-01

178

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

NASA Technical Reports Server (NTRS)

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

Calise, A. J.; Rysdyk, R.

1996-01-01

179

A Correlation Between Flight-Determined Derivatives and Wind-Tunnel Data for the X-24B Research Aircraft  

NASA Technical Reports Server (NTRS)

Longitudinal and lateral-directional estimates of the aerodynamic derivatives of the X-24B research aircraft were obtained from flight data by using a modified maximum likelihood estimation method. Data were obtained over a Mach number range from 0.35 to 1.72 and over an angle of attack range from 3.5 deg. to 15.7 deg. Data are presented for a subsonic and transonic configuration. The flight derivatives were generally consistent and documented the aircraft well. The correlation between the flight data and wind-tunnel predictions is presented and discussed.

Sim, Alex G.

1997-01-01

180

Production Support Flight Control Computers: Research Capability for F/A-18 Aircraft at Dryden Flight Research Center  

NASA Technical Reports Server (NTRS)

NASA Dryden Flight Research Center (DFRC) is working with the United States Navy to complete ground testing and initiate flight testing of a modified set of F/A-18 flight control computers. The Production Support Flight Control Computers (PSFCC) can give any fleet F/A-18 airplane an in-flight, pilot-selectable research control law capability. NASA DFRC can efficiently flight test the PSFCC for the following four reasons: (1) Six F/A-18 chase aircraft are available which could be used with the PSFCC; (2) An F/A-18 processor-in-the-loop simulation exists for validation testing; (3) The expertise has been developed in programming the research processor in the PSFCC; and (4) A well-defined process has been established for clearing flight control research projects for flight. This report presents a functional description of the PSFCC. Descriptions of the NASA DFRC facilities, PSFCC verification and validation process, and planned PSFCC projects are also provided.

Carter, John F.

1997-01-01

181

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

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

182

A History of Full-Scale Aircraft and Rotorcraft Crash Testing and Simulation at NASA Langley Research Center  

NASA Technical Reports Server (NTRS)

This paper summarizes 2-1/2 decades of full-scale aircraft and rotorcraft crash testing performed at the Impact Dynamics Research Facility (IDRF) located at NASA Langley Research Center in Hampton, Virginia. The IDRF is a 240-ft.-high steel gantry that was built originally as a lunar landing simulator facility in the early 1960's. It was converted into a full-scale crash test facility for light aircraft and rotorcraft in the early 1970 s. Since the first full-scale crash test was preformed in February 1974, the IDRF has been used to conduct: 41 full-scale crash tests of General Aviation (GA) aircraft including landmark studies to establish baseline crash performance data for metallic and composite GA aircraft; 11 full-scale crash tests of helicopters including crash qualification tests of the Bell and Sikorsky Advanced Composite Airframe Program (ACAP) prototypes; 48 Wire Strike Protection System (WSPS) qualification tests of Army helicopters; 3 vertical drop tests of Boeing 707 transport aircraft fuselage sections; and, 60+ crash tests of the F-111 crew escape module. For some of these tests, nonlinear transient dynamic codes were utilized to simulate the impact response of the airframe. These simulations were performed to evaluate the capabilities of the analytical tools, as well as to validate the models through test-analysis correlation. In September 2003, NASA Langley closed the IDRF facility and plans are underway to demolish it in 2007. Consequently, it is important to document the contributions made to improve the crashworthiness of light aircraft and rotorcraft achieved through full-scale crash testing and simulation at the IDRF.

Jackson, Karen E.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.; Lyle, Karen H.

2004-01-01

183

Integrating Multiple Autonomous Underwater Vessels, Surface Vessels and Aircraft into Oceanographic Research Vessel Operations  

NASA Astrophysics Data System (ADS)

Autonomous platforms are increasingly used as components of Integrated Ocean Observing Systems and oceanographic research cruises. Systems deployed can include gliders or propeller-driven autonomous underwater vessels (AUVs), autonomous surface vessels (ASVs), and unmanned aircraft systems (UAS). Prior field campaigns have demonstrated successful communication, sensor data fusion and visualization for studies using gliders and AUVs. However, additional requirements exist for incorporating ASVs and UASs into ship operations. For these systems to be optimally integrated into research vessel data management and operational planning systems involves addressing three key issues: real-time field data availability, platform coordination, and data archiving for later analysis. A fleet of AUVs, ASVs and UAS deployed from a research vessel is best operated as a system integrated with the ship, provided communications among them can be sustained. For this purpose, Disruptive Tolerant Networking (DTN) software protocols for operation in communication-challenged environments help ensure reliable high-bandwidth communications. Additionally, system components need to have considerable onboard autonomy, namely adaptive sampling capabilities using their own onboard sensor data stream analysis. We discuss Oceanographic Decision Support System (ODSS) software currently used for situational awareness and planning onshore, and in the near future event detection and response will be coordinated among multiple vehicles. Results from recent field studies from oceanographic research vessels using AUVs, ASVs and UAS, including the Rapid Environmental Picture (REP-12) cruise, are presented describing methods and results for use of multi-vehicle communication and deliberative control networks, adaptive sampling with single and multiple platforms, issues relating to data management and archiving, and finally challenges that remain in addressing these technological issues. Significantly, the use of UAS on oceanographic research vessels is just beginning. We report on several initial field efforts which demonstrated that UAS improve spatial and temporal mapping of ocean features, as well as monitoring marine mammal populations, ocean color, sea ice and wave fields and air-sea gas exchange. These studies however also confirm the challenges for shipboard computer systems ingesting and archiving UAS high resolution video, SAR and lidar data. We describe the successful inclusion of DTN communications for: 1) passing video data between two UAS or a UAS and ship; 2) for inclusion of ASVs as communication nodes for AUVs; as well as, 3) enabling extension of adaptive sampling software from AUVs and ASVs to include UAS. In conclusion, we describe how autonomous sampling systems may be best integrated into shipboard oceanographic vessel research to provide new and more comprehensive time-space ocean and atmospheric data collection that is important not only for scientific study, but also for sustainable ocean management, including emergency response capabilities. The recent examples of such integrated studies highlighted confirm ocean and atmospheric studies can more cost-effectively pursued, and in some cases only accomplished, by combining underwater, surface and aircraft autonomous systems with research vessel operations.

McGillivary, P. A.; Borges de Sousa, J.; Martins, R.; Rajan, K.

2012-12-01

184

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

NASA Technical Reports Server (NTRS)

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

1977-01-01

185

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

186

Performance of WVSS-II hygrometers on the FAAM Research Aircraft  

NASA Astrophysics Data System (ADS)

We compare the performance of five hygrometers fitted to the Facility for Airborne Atmospheric Measurement's (FAAM) BAe 146-301 research aircraft using data from approximately one hundred flights executed over the course of two years under a wide range of conditions. Bulk comparison of cloud free data show good agreement between chilled mirror hygrometers and a WVSS-II fed from a modified Rosemount inlet but that a WVSS-II fed from the standard flush inlet appears to over read compared to the other instruments, except at higher humidities. Statistical assessment of hygrometer performance in cloudy conditions is problematic due to the variable nature of clouds, so a number of case studies are used instead to investigate the performance of the hygrometers in sub optimal conditions. It is found that the flush inlet is not susceptible to either liquid or solid water but that the Rosemount inlet has a significant susceptibility to liquid water; it is not susceptible to ice. In all conditions the WVSS-II respond much more rapidly than the chilled mirror devices, with the flush inlet-fed WVSS-II being more rapid than that connected to the Rosemount.

Vance, A. K.; Abel, S. J.; Cotton, R. J.; Woolley, A. M.

2014-08-01

187

The X-43A hypersonic research aircraft and its modified Pegasus booster rocket mounted to NASA's NB  

NASA Technical Reports Server (NTRS)

The first of three X-43A hypersonic research aircraft and its modified Pegasus booster rocket recently underwent combined systems testing while mounted to NASA's NB-52B carrier aircraft at the Dryden Flight Research Center, Edwards, California. The combined systems test was one of the last major milestones in the Hyper-X research program before the first X-43A flight. One of the major goals of the Hyper-X program is flight validation of airframe-integrated, air-breathing propulsion system, which so far have only been tested in ground facilities, such as wind tunnels. The X-43A flights will be the first actual flight tests of an aircraft powered by a revolutionary supersonic-combustion ramjet ('scramjet') engine capable of operating at hypersonic speeds above Mach 5 (five times the speed of sound). The X-43A design uses the underbody of the aircraft to form critical elements of the engine. The forebody shape helps compress the intake airflow, while the aft section acts as a nozzle to direct thrust. The 12-foot, unpiloted research vehicle was developed and built by MicroCraft Inc., Tullahoma, Tenn., under NASA contract. The booster, built by Orbital Sciences Corp., Dulles, Va., will accelerate the X-43A after the X-43A/booster 'stack' is air-launched from NASA's venerable NB-52 mothership. The X-43A will separate from the rocket at a predetermined altitude and speed and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it descends into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10.

2001-01-01

188

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

NASA Technical Reports Server (NTRS)

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

Yaniec, John S.

1995-01-01

189

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

NASA Astrophysics Data System (ADS)

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

Zulueta, Rommel Callejo

190

Advanced turboprop aircraft noise annoyance - A review of recent NASA research  

NASA Astrophysics Data System (ADS)

Passenger and community response to advanced turboprop aircraft noise are studied. Four experiments were conducted utilizing an aircraft noise synthesis system, an exterior effects room, an anechoic listening room, and a Space Station/aircraft acoustic apparatus; the experimental conditions and procedures for the psychoacoustic studies are described. The community noise studies involved evaluating the effects of various tonal characteristics on annoyance. It was observed that the frequency envelope shape did not effect annoyance; however, the interaction of the fundamental frequency with tone-to-broadband noise ratio did have a large effect on annoyance. The effects of low frequency tones, turbulent boundary layer noise, and tonal beats on passenger annoyance are investigated. The data reveal that passenger annoyance is greater for a given level of boundary layer noise when tones are at levels sufficient to increase the overall sound pressure level within the cabin. The annoyance response of an advanced turboprop and a conventional aircraft are compared. It is determined that the flyover noise level for the turboprop aircraft is not more annoying than that of a conventional aircraft.

McCurdy, D. A.; Leatherwood, J. D.; Shepherd, K. P.

1986-07-01

191

Advanced turboprop aircraft noise annoyance - A review of recent NASA research  

NASA Technical Reports Server (NTRS)

Passenger and community response to advanced turboprop aircraft noise are studied. Four experiments were conducted utilizing an aircraft noise synthesis system, an exterior effects room, an anechoic listening room, and a Space Station/aircraft acoustic apparatus; the experimental conditions and procedures for the psychoacoustic studies are described. The community noise studies involved evaluating the effects of various tonal characteristics on annoyance. It was observed that the frequency envelope shape did not effect annoyance; however, the interaction of the fundamental frequency with tone-to-broadband noise ratio did have a large effect on annoyance. The effects of low frequency tones, turbulent boundary layer noise, and tonal beats on passenger annoyance are investigated. The data reveal that passenger annoyance is greater for a given level of boundary layer noise when tones are at levels sufficient to increase the overall sound pressure level within the cabin. The annoyance response of an advanced turboprop and a conventional aircraft are compared. It is determined that the flyover noise level for the turboprop aircraft is not more annoying than that of a conventional aircraft.

Mccurdy, D. A.; Leatherwood, J. D.; Shepherd, K. P.

1986-01-01

192

Study of the application of advanced technologies to long-range transport aircraft. Volume 2: Research and development requirements  

NASA Technical Reports Server (NTRS)

Investigations were conducted to evaluate the relative benefits attainable through the exploitation of advanced technologies and to identify future research and development efforts required to permit the application of selected technologies to transport aircraft entering commercial operation in 1985. Results show that technology advances, particularly in the areas of composite materials, supercritical aerodynamics, and active control systems, will permit the development of long-range, high-payload commercial transports operating at high-subsonic speeds with direct operating costs lower than those of current aircraft. These advanced transports also achieve lower noise levels and lower engine pollutant emissions than current transports. Research and development efforts, including analytical investigations, laboratory test programs, and flight test programs, are required in essentially all technology areas to achieve the potential technology benefits.

Lange, R. H.; Sturgeon, R. F.; Adams, W. E.; Bradley, E. S.; Cahill, J. F.; Eudaily, R. R.; Hancock, J. P.; Moore, J. W.

1972-01-01

193

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

194

Small transport aircraft technology  

NASA Technical Reports Server (NTRS)

Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.

Williams, L. J.

1983-01-01

195

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

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

196

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

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

197

EXPERIMENTAL RESEARCH ON PHOTOCATALYTIC OXIDATION AIR PURIFICATION TECHNOLOGY APPLIED TO AIRCRAFT CABINS  

Microsoft Academic Search

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

YX Sun; L Lagercrantz

2005-01-01

198

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

Microsoft Academic Search

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

Yuexia Sun; Lei Fang; David P. Wyona; Peter Strøm-Tejsena

199

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

Microsoft Academic Search

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

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

2008-01-01

200

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

NASA Technical Reports Server (NTRS)

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

Davis, Steven B.

1990-01-01

201

Unmanned aircraft research in support of NextGen trajectory based operations  

Microsoft Academic Search

The two predominately challenging issues facing the development of standards for unmanned aircraft systems (UAS) integration into the national air space (NAS) are collision avoidance and UAS command and control link integrity. This paper discusses an approach for addressing the collision avoidance issues affecting UAS and shows how advances in this area can contribute to the advancement of the Next

Kevin McEntee; B. Nix; G. Lloyd

2008-01-01

202

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

NASA Technical Reports Server (NTRS)

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

Zumwalt, Glen W.

1989-01-01

203

The European Research Infrastructure IAGOS - From dedicated field studies to routine observations of the atmosphere by instrumented passenger aircraft  

NASA Astrophysics Data System (ADS)

The global distribution of trace species is controlled by a complex interplay between natural and anthropogenic sources and sinks, atmospheric short- to long-range transport, and in future by diverse, largely not yet quantified feedback mechanisms such as enhanced evaporation of water vapour in a warming climate or possibly the release of methane from melting marine clathrates. Improving global trace gas budgets and reducing the uncertainty of climate predictions crucially requires representative data from routine long-term observations as independent constraint for the evaluation and improvement of model parameterizations. IAGOS (In-service Aircraft for a Global Observing System; www.iagos.org) is a new European Research Infrastructure which operates a unique global observing system by deploying autonomous instruments aboard a fleet of passenger aircraft. IAGOS consists of two complementary building blocks: IAGOS-CORE deploys newly developed high-tech instrumentation for regular in-situ measurements of atmospheric chemical species (O3, CO, CO2, NOx, NOy, H2O, CH4), aerosols and cloud particles. Involved airlines ensure global operation of the network. In IAGOS-CARIBIC a cargo container is operated as a flying laboratory aboard one passenger aircraft. IAGOS aims at the provision of long-term, frequent, regular, accurate, and spatially resolved in-situ observations of the atmospheric chemical composition in the UTLS and the extra tropical troposphere and on vertical profiles of greenhouse gases, reactive trace gases and aerosols throughout the troposphere. 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 provides data for fundamental scientific research and for policy makers, including air quality forecasting, verification of CO2 emissions and Kyoto protocol monitoring, numerical weather prediction, and validation of satellite products. There is also a strong interest of the aviation sector by means of airlines who agreed to provide free transportation of the equipment. Reasons are their intention to contribute to a better understanding of climate change and the budgets of greenhouse gases with particular emphasis on the impact of aviation. Such knowledge forms the scientific basis for the development of abatement strategies and emission trading. IAGOS is planned to be an open infrastructure in two aspects. The data measured onboard the aircraft will be transferred to a central data base and interested users can access the data base free of charge after having signed a data protocol. Access to real-time data will also be free of charge and is foreseen to be achieved in the framework of Global Monitoring for Environment and Security (GMES) via the European meteorological network. The presentation will introduce the research infrastructure and its role in the emerging integrated global atmospheric observing system. Data management, quality assurance tools and links between IAGOS and other research infrastructures in the domain of atmospheric observation will be discussed.

Petzold, Andreas; Volz-Thomas, Andreas; Gerbig, Christoph; Thouret, Valerie; Cammas, Jean-Pierre; Brenninkmeijer, Carl A. M.; Iagos Team

2013-04-01

204

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

NASA Technical Reports Server (NTRS)

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

Sorensen, J. A.; Goka, T.

1982-01-01

205

A review of US Army aircrew-aircraft integration research programs  

NASA Technical Reports Server (NTRS)

If the U.S. Army's desire to develop a one crew version of the Light Helicopter Family (LHX) helicopter is to be realized, both flightpath management and mission management will have to be performed by one crew. Flightpath management, the helicopter pilot, and the handling qualities of the helicopter were discussed. In addition, mission management, the helicopter pilot, and pilot control/display interface were considered. Aircrew-aircraft integration plans and programs were reviewed.

Key, D. C.; Aiken, E. W.

1984-01-01

206

V/STOL tilt rotor research aircraft. Volume 3: Ship 2 instrumentation  

NASA Technical Reports Server (NTRS)

Information covering sensor cables, sensor installation, and sensor calibration for the XV-15 aircraft number 2 is included. For each junction box (J-box) designation there is a schematic of the J-box disconnect harness, instrumentation worksheets which show sensor location, and calibration data sheets for each sensor associated with that J-box. An index of measurement data codes to J-box locations is given in a table. Cross references are given.

1978-01-01

207

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

NASA Technical Reports Server (NTRS)

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

1978-01-01

208

The SR71 Test Bed Aircraft: A Facility for High-Speed Flight Research  

Microsoft Academic Search

The SR-71 test bed aircraft is shown to be a unique platform to flight-test large experiments tosupersonic Mach numbers. The test bed hardware mounted on the SR-71 upper fuselage is described.This test bed hardware is composed of a fairing structure called the "canoe" and a large "reflection plane"flat plate for mounting experiments. Total experiment weights, including the canoe and reflection

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

2000-01-01

209

NACA research on combustors for aircraft gas turbines I : effects of operating variables on steady-state performance  

NASA Technical Reports Server (NTRS)

Some of the systematic research conducted by the NACA on aircraft gas-turbine combustors is reviewed. Trends depicting the effect of inlet-air pressure, temperature, and velocity and fuel-air ratio on performance characteristics, such as combustion efficiency, maximum temperature rise attainable, pressure loss, and combustor-outlet temperature distribution are described for a variety of turbojet combustors of the liquid-fuel type. These trends are further discussed as effects significant to the turbojet engine, such as altitude operational limits, specific fuel consumption, thrust, acceleration, and turbine life.

Olson, Walter T; Childs, J Howard

1950-01-01

210

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

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

211

A perspective on 15 years of proof-of-concept aircraft development and flight research at Ames-Moffett by the Rotorcraft and Powered-Lift Flight Projects Division, 1970-1985  

NASA Technical Reports Server (NTRS)

A proof-of-concept (POC) aircraft is defined and the concept of interest described for each of the six aircraft developed by the Ames-Moffet Rotorcraft and Powered-Lift Flight Projects Division from 1970 through 1985; namely, the OV-10, the C-8A Augmentor Wing, the Quiet Short-Haul Research Aircraft (QSRA), the XV-15 Tilt Rotor Research Aircraft (TRRA), the Rotor Systems Research Aircraft (RSRA)-compound, and the yet-to-fly RSRA/X-Wing Aircraft. The program/project chronology and most noteworthy features of the concepts are reviewed. The paper discusses the significance of each concept and the project demonstrating it; it briefly looks at what concepts are on the horizon as potential POC research aircraft and emphasizes that no significant advanced concept in aviation technology has ever been accepted by civilian or military users without first completing a demonstration through flight testing.

Few, David D.

1987-01-01

212

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

NASA Technical Reports Server (NTRS)

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

Angelici, Gary; Popovici, Lidia; Skiles, Jay

1991-01-01

213

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

214

A flight evaluation of a trailing anemometer for low-speed calibrations of airspeed systems on research aircraft  

NASA Technical Reports Server (NTRS)

Research airspeed systems on three low-speed general aviation airplanes were calibrated by the trailing anemometer method. Each airplane was fitted with an NASA pitot-static pressure tube mounted on either a nose or wing boom. The uncalibrated airspeed systems contained residual static-pressure position errors which were too large for high-accuracy flight research applications. The trailing anemometer calibration was in agreement with the tower flyby calibration for the one aircraft for which the comparison was made. The continuous deceleration technique for the trailing anemometer method offers reduced test time with no appreciable loss of accuracy for airspeed systems with pitot-static system lag characteristics similar to those described.

Fisher, B. D.; Holmes, B. J.; Stough, H. P., III

1978-01-01

215

Research on compiling fatigue load spectrum of individual aircraft and analysis of fatigue life based on flight data  

Microsoft Academic Search

Compiling fatigue load spectrum is the precondition and basement of fatigue life prediction, simulation experiments and fatigue strength analysis of aircraft. The method of air fleet life is used on management of homotype aircraft life for a long term, that is the process of achievement on safe life index by fatigue experiment of aircraft overall dimension on condition of standard

Yan Li; Zhao Wang; YueLiang Chen; Yong Zhang; WengSheng Sun

2012-01-01

216

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

NASA Technical Reports Server (NTRS)

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

Cheng, R. Y. K.

1977-01-01

217

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

218

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

219

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

220

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

NASA Technical Reports Server (NTRS)

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

Zavala, Eddie

1997-01-01

221

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

NASA Technical Reports Server (NTRS)

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

1977-01-01

222

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

223

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

NASA Technical Reports Server (NTRS)

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

Graham, Robert W.

1989-01-01

224

Lewis icing research tunnel test of the aerodynamic effects of aircraft ground deicing/anti-icing fluids  

NASA Technical Reports Server (NTRS)

A wind tunnel investigation of the effect of aircraft ground deicing/anti-icing fluids on the aerodynamic characteristics of a Boeing 737-200ADV airplane was conducted. The test was carried out in the NASA Lewis Icing Research Tunnel. Fluids tested include a Newtonian deicing fluid, three non-Newtonian anti-icing fluids commercially available during or before 1988, and eight new experimental non-Newtonian fluids developed by four fluid manufacturers. The results show that fluids remain on the wind after liftoff and cause a measurable lift loss and drag increase. These effects are dependent on the high-lift configuration and on the temperature. For a configuration with a high-lift leading-edge device, the fluid effect is largest at the maximum lift condition. The fluid aerodynamic effects are related to the magnitude of the fluid surface roughness, particularly in the first 30 percent chord. The experimental fluids show a significant reduction in aerodynamic effects.

Runyan, L. James; Zierten, Thomas A.; Hill, Eugene G.; Addy, Harold E., Jr.

1992-01-01

225

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

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

226

The Aircraft Morphing Program  

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

227

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

NASA Technical Reports Server (NTRS)

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

Kimbell, M.; Whitener, A.

1980-01-01

228

X-15s, HL-10, M2-F1, and M2-F2 Lifting Body research aircraft in main NASA hangar  

NASA Technical Reports Server (NTRS)

Hangar 4802 at the NASA Flight Research Center in 1966. Aircraft on left include (left to right): HL-10, M2-F2, M2-F1, F-4A, F5D-1, F-104 (barely visible) and C-47. Aircraft on the right side (left to right) include: X-15-1 (56-6670), X-15-3 (56-6672), and X-15-2 (56-6671). Hangar 4802 had been the main hangar at the Flight Research Center (FRC--now the Dryden Flight Research Center, Edwards, CA) and before that, the High-Speed Flight Station, since 1954. During 1966, the two main flight research projects at the FRC were the lifting bodies (including the M2-F1, M2-F2, and HL-10) and the X-15.

1966-01-01

229

Advanced ATC: An aircraft perspective  

NASA Technical Reports Server (NTRS)

The principal operational improvements desired by commercial aircraft operators in the United States are efficient aircraft operations and delay reductions at the major terminals. Efforts underway within the Advanced Transport Operating Systems Program at the Langley Research Center to provide a technology basis for reducing delay while improving aircraft efficiency are discussed. The principal thrust is the development of time-based traffic control concepts which could be used within the framework of the upgraded National Airspace System and which would allow conventionally equipped aircraft to operate in a manner compatible with advanced aircraft.

Credeur, Leonard; Williams, David H.; Howell, William E.; Spitzer, Cary R.

1986-01-01

230

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

231

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

232

Predicted flight characteristics of the augmentor wing jet STOL research aircraft  

NASA Technical Reports Server (NTRS)

An existing deHavilland C-8A airplane has been modified into an augmentor wing flight test vehicle. Research objectives are to verify the augmentor flap concept and to produce data for STOL airworthiness criteria. The Modified C-8A provides the means for jet-STOL flight research down to a 60 knot approach speed. The airplane has a high thrust-to-weight ratio, high-lift flap system, vectored thrust, powerful flight controls, and lateral-directional stability augmentation system. Normal performance and handling qualities are expected to be satisfactory. Analysis and piloted simulator results indicate that stability and control characteristics in conventional flight are rated satisfactory. Handling qualities in the STOL regime are also generally satisfactory, although pilot workload is high about the longitudinal axis.

Spitzer, R. E.

1972-01-01

233

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

SciTech Connect

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

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

1995-08-01

234

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

NASA Technical Reports Server (NTRS)

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

White, Samuel G.; Gilinsky, Mikhail M.

1997-01-01

235

The insertion of human dynamics models in the flight control loops of V/STOL research aircraft. Appendix 2: The optimal control model of a pilot in V/STOL aircraft control loops  

NASA Technical Reports Server (NTRS)

An overview is presented of research work focussed on the design and insertion of classical models of human pilot dynamics within the flight control loops of V/STOL aircraft. The pilots were designed and configured for use in integrated control system research and design. The models of human behavior that were considered are: McRuer-Krendel (a single variable transfer function model); and Optimal Control Model (a multi-variable approach based on optimal control and stochastic estimation theory). These models attempt to predict human control response characteristics when confronted with compensatory tracking and state regulation tasks. An overview, mathematical description, and discussion of predictive limitations of the pilot models is presented. Design strategies and closed loop insertion configurations are introduced and considered for various flight control scenarios. Models of aircraft dynamics (both transfer function and state space based) are developed and discussed for their use in pilot design and application. Pilot design and insertion are illustrated for various flight control objectives. Results of pilot insertion within the control loops of two V/STOL research aricraft (Sikorski Black Hawk UH-60A, McDonnell Douglas Harrier II AV-8B) are presented and compared against actual pilot flight data. Conclusions are reached on the ability of the pilot models to adequately predict human behavior when confronted with similar control objectives.

Zipf, Mark E.

1989-01-01

236

ABSTRACT: The purpose of our study consists in the research of new ways of designing reinforced concrete structures submitted to commercial aircraft impact. We will particularly focus on the shaking resulting from such load case. The cutoff  

E-print Network

ABSTRACT: The purpose of our study consists in the research of new ways of designing reinforced concrete structures submitted to commercial aircraft impact. We will particularly focus on the shaking induced by an aircraft impact on an industrial structure requires dynamic studies. The response

Boyer, Edmond

237

ABSTRACT: The purpose of our study consists in the research of new ways of designing reinforced concrete structures submitted to commercial aircraft impact. We will particularly focus on the shaking resulting from such load case. The cutoff  

E-print Network

with a Taguchi experimental design. The calculation of the shaking induced by an aircraft impact on an industrialABSTRACT: The purpose of our study consists in the research of new ways of designing reinforced concrete structures submitted to commercial aircraft impact. We will particularly focus on the shaking

Boyer, Edmond

238

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

NASA Technical Reports Server (NTRS)

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

Kelly, Michael J.

2013-01-01

239

Aircraft Noise  

NASA Astrophysics Data System (ADS)

Aircraft industry is exposed to increasing public pressure aiming at a continuing reduction of aircraft noise levels. This is necessary to both compensate for the detrimental effect on noise of the expected increase in air traffic and improve the quality of living in residential areas around airports.

Michel, Ulf; Dobrzynski, Werner; Splettstoesser, Wolf; Delfs, Jan; Isermann, Ullrich; Obermeier, Frank

240

Chemiluminescent methods and instruments for monitoring of the atmosphere and satellite validation on board of research aircrafts and unmanned aerial vehicles  

NASA Astrophysics Data System (ADS)

The results of development of instruments based on heterophase chemiluminescence for measurements of space distribution of ozone and nitrogen oxides concentrations on board of research aircrafts and unmanned aerial vehicles carried out in Central Aerological Observatory are presented. Some results of atmospheric investigations on board of research aircrafts M55 “Geophysica” (Russia) and “Falcon” (Germany) carried out using developed instruments in frame of international projects are demonstrated. Small and low power instruments based on chemiluminescent principle for UAV are developed. The results of measurements on board of UAV are shown. The development can be used for satellite data validation, as well as operative environmental monitoring of contaminated areas in particular, chemical plants, natural and industrial disasters territories, areas and facilities for space purposes etc.

Sitnikov, Nikolay; Borisov, Yuriy; Akmulin, Dimitry; Chekulaev, Igor; Sitnikova, Vera; Ulanovsky, Alexey; Sokolov, Alexey

241

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

242

Unmanned Aircraft Systems at NASA Dryden  

NASA Video Gallery

NASA Dryden has a heritage of developmental and operational experience with unmanned aircraft systems. Work on Boeing's sub-scale X-36 Tailless Fighter Agility Research Aircraft, X-48 Blended Wing ...

243

Follow on Research for Multi-Utility Technology Test Bed Aircraft at NASA Dryden Flight Research Center (FY13 Progress Report)  

NASA Technical Reports Server (NTRS)

Modern aircraft employ a significant fraction of their weight in composite materials to reduce weight and improve performance. Aircraft aeroservoelastic models are typically characterized by significant levels of model parameter uncertainty due to the composite manufacturing process. Small modeling errors in the finite element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of Multi Utility Technology Test-bed (MUTT) aircraft is the flight demonstration of active flutter suppression, and therefore in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of MUTT aircraft. The ground vibration test-validated structural dynamic finite element model of the MUTT aircraft is created in this study. The structural dynamic finite element model of MUTT aircraft is improved using the in-house Multi-disciplinary Design, Analysis, and Optimization tool. In this study, two different weight configurations of MUTT aircraft have been improved simultaneously in a single model tuning procedure.

Pak, Chan-Gi

2013-01-01

244

Aircraft equipment  

NASA Technical Reports Server (NTRS)

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

1977-01-01

245

Human systems and aircraft maintenance  

Microsoft Academic Search

Research in normal operational environments indicates that the formal requirements for the aircraft maintenance system are frequently not fully or effectively implemented in practice. This gives rise to a pervasive ‘double standard’ with no effective means of reconciling official and unofficial operational practice. A systems strategy for human-centred management in aircraft maintenance is being developed in a number of European

Nick McDonald

2001-01-01

246

Alternative aircraft fuels technology  

NASA Technical Reports Server (NTRS)

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

Grobman, J.

1976-01-01

247

Conceptual design, evaluation and research identification for Remote Augmented Propulsive Lift Systems (RALS) with ejectors for VTOL aircraft  

NASA Technical Reports Server (NTRS)

Ejector concepts for use with a remote augmented lift system (RALS) exhaust nozzle were studied. A number of concepts were considered and three were selected as having the greatest promise of providing the desired aircraft and exhaust gas cooling and lift enhancement. A scale model test program is recommended to explore the effects of the more important parameters on ejector performance.

Willis, W. S.; Konarski, M.; Sutherland, M. V.

1982-01-01

248

Pathfinder aircraft in flight  

NASA Technical Reports Server (NTRS)

The Pathfinder research aircraft's wing structure was clearly defined as it soared under a clear blue sky during a test flight July 27, 1995, from Dryden Flight Research Center, Edwards, California. The center section and outer wing panels of the aircraft had ribs constructed of thin plastic foam, while the ribs in the inner wing panels are fabricated from lightweight composite material. Developed by AeroVironment, Inc., the Pathfinder was one of several unmanned aircraft being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. 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.)

1995-01-01

249

Pathfinder Aircraft in Flight  

NASA Technical Reports Server (NTRS)

The Pathfinder research aircraft's wing structure was clearly defined as it soared under a clear blue sky during a test flight July 27, 1995, from Dryden Flight Research Center, Edwards, California. The center section and outer wing panels of the aircraft had ribs constructed of thin plastic foam, while the ribs in the inner wing panels are fabricated from lightweight composite material. Developed by AeroVironment, Inc., the Pathfinder was one of several unmanned aircraft being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. 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.

1995-01-01

250

Progress in supersonic cruise aircraft technology  

NASA Technical Reports Server (NTRS)

The supersonic cruise aircraft research program identified significant improvements in the technology areas of propulsion, aerodynamics, structures, takeoff and landing procedures, and advanced configuration concepts. Application of these technology areas to a commercial aircraft is discussed. An advanced SST family of aircraft which may be environmentally acceptable, have flexible range-payload capability, and be economically viable is projected.

Driver, C.

1978-01-01

251

Analyses of Aircraft Responses to Atmospheric Turbulence  

Microsoft Academic Search

The response of aircraft to stochastic atmospheric turbulence plays an important role in aircraft-design (load calculations), Flight Control System (FCS) design and flight-simulation (handling qualities research and pilot training). In order to simulate these aircraft responses, an accurate mathematical model is required. Two classical models will be discussed in this thesis, that is the Delft University of Technology (DUT) model

W. H. J. J. Van Staveren

2003-01-01

252

UNMANNED AIRCRAFT HAZARDS AND THEIR IMPLICATIONS FOR Kelly J. Hayhurst, Jeffrey M. Maddalon, Paul S. Miner, NASA Langley Research Center, Hampton, VA  

E-print Network

Andy 5B1-1 UNMANNED AIRCRAFT HAZARDS AND THEIR IMPLICATIONS FOR REGULATION Kelly J. Hayhurst McCormick, Certification Services, Inc., Eastsound, WA Abstract Use of unmanned aircraft systems framework, for safely integrating these aircraft into civil airspace. Introduction An unmanned aircraft

Maddalon, Jeffrey M.

253

STOL Aircraft  

NASA Technical Reports Server (NTRS)

Michael E. Fisher, President of AeroVisions International, has introduced the Culex light twin engine aircraft which offers economy of operation of a single engine plane, the ability to fly well on one engine, plus the capability of flying from short, unimproved fields of takeoff and landing distances less than 35 feet. Key element of design is an airfoil developed by Langley. Culex was originally intended to be factory built aircraft for special utility markets. However, it is now offered as a build-it-yourself kit plane.

1988-01-01

254

Pathfinder aircraft flight  

NASA Technical Reports Server (NTRS)

The Pathfinder research aircraft's wing structure is clearly defined as it soars under a clear blue sky during a test flight from Dryden Flight Research Center, Edwards, California, in November of 1996. 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.)

1996-01-01

255

Pathfinder aircraft checkout flight  

NASA Technical Reports Server (NTRS)

The Pathfinder solar-powered research aircraft is silhouetted against a clear blue sky as it soars aloft during a checkout flight from the Dryden Flight Research Center, Edwards, California, in November, 1996. 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.)

1996-01-01

256

Pathfinder aircraft in flight  

NASA Technical Reports Server (NTRS)

The Pathfinder solar-powered research aircraft is silhouetted against a clear blue sky as it soars aloft during a checkout flight from the Dryden Flight Research Center, Edwards, California, November, 1996. 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.)

1996-01-01

257

Pathfinder aircraft in flight  

NASA Technical Reports Server (NTRS)

The Pathfinder research aircraft's solar cell arrays are prominently displayed as it touches down on the bed of Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, following a test flight. The solar arrays covered more than 75 percent of Pathfinder's upper wing surface, and provided electricity to power its six electric motors, flight controls, communications links and a host of scientific sensors. 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.)

1996-01-01

258

Pathfinder aircraft in flight  

NASA Technical Reports Server (NTRS)

The Pathfinder solar-powered research aircraft heads for landing on the bed of Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, after a successful test flight Nov. 19, 1996. 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.)

1996-01-01

259

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

260

Arnold Schwarzenegger AIRCRAFT MEASUREMENTS OF THE  

E-print Network

Arnold Schwarzenegger Governor AIRCRAFT MEASUREMENTS OF THE IMPACTS OF POLLUTION AEROSOLS ON CLOUDS of Jerusalem Seeding Operation & Atmospheric Research Desert Research Institute, University of Nevada Seeding Operations & Atmospheric Research, POB 130, Plains TX 79355 James G. Hudson Desert Research

261

Neural networks for aircraft control  

NASA Technical Reports Server (NTRS)

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

Linse, Dennis

1990-01-01

262

Jet aircraft hydrocarbon fuels technology  

NASA Technical Reports Server (NTRS)

A broad specification, referee fuel was proposed for research and development. This fuel has a lower, closely specified hydrogen content and higher final boiling point and freezing point than ASTM Jet A. The workshop recommended various priority items for fuel research and development. Key items include prediction of tradeoffs among fuel refining, distribution, and aircraft operating costs; combustor liner temperature and emissions studies; and practical simulator investigations of the effect of high freezing point and low thermal stability fuels on aircraft fuel systems.

Longwell, J. P. (editor)

1978-01-01

263

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

264

An inverse-modelling approach for frequency response correction of capacitive humidity sensors in ABL research with small remotely piloted aircraft (RPA)  

NASA Astrophysics Data System (ADS)

The measurement of water vapour concentration in the atmosphere is an ongoing challenge in environmental research. Satisfactory solutions exist for ground-based meteorological stations and measurements of mean values. However, carrying out advanced research of thermodynamic processes aloft as well, above the surface layer and especially in the atmospheric boundary layer (ABL), requires the resolution of small-scale turbulence. Sophisticated optical instruments are used in airborne meteorology with manned aircraft to achieve the necessary fast-response measurements of the order of 10 Hz (e.g. LiCor 7500). Since these instruments are too large and heavy for the application on small remotely piloted aircraft (RPA), a method is presented in this study that enhances small capacitive humidity sensors to be able to resolve turbulent eddies of the order of 10 m. The sensor examined here is a polymer-based sensor of the type P14-Rapid, by the Swiss company Innovative Sensor Technologies (IST) AG, with a surface area of less than 10 mm2 and a negligible weight. A physical and dynamical model of this sensor is described and then inverted in order to restore original water vapour fluctuations from sensor measurements. Examples of flight measurements show how the method can be used to correct vertical profiles and resolve turbulence spectra up to about 3 Hz. At an airspeed of 25 m s-1 this corresponds to a spatial resolution of less than 10 m.

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

2014-09-01

265

Pathfinder aircraft in flight  

NASA Technical Reports Server (NTRS)

The unique Pathfinder solar-powered flying wing, is shown during a checkout flight from the Dryden Flight Research Center, Edwards, California. This two-hour low-altitude flight over Rogers Dry Lake, Nov. 19, 1996, served to test aircraft systems and functional procedures, according to officials of AeroVironment, Inc., Pathfinder's developer and operator. 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.)

1996-01-01

266

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 101, NO. D22, PAGES 29,075-29,080, DECEMBER 20, 1996 An aircraft measurementtechniquefor formaldehyde  

E-print Network

,Canada.In thispaperwe give a description of the design and operation of this aircraft techni An aircraft measurementtechniquefor formaldehyde and solublecarbonyl compounds Yin-Nan Lee and measuringthemultioxygenatedcarbonylcompoundsmentioned above in addition to FA. Because of the fact that only the sampler was outfitted on the aircraft

267

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

268

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

NASA Technical Reports Server (NTRS)

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

Kuhn, Richard E.

1986-01-01

269

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

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

270

Langley Aircraft Landing Dynamics Facility  

NASA Technical Reports Server (NTRS)

The Langley Research Center has recently upgraded the Landing Loads Track (LLT) to improve the capability of low-cost testing of conventional and advanced landing gear systems. The unique feature of the Langley Aircraft Landing Dynamics Facility (ALDF) is the ability to test aircraft landing gear systems on actual runway surfaces at operational ground speeds and loading conditions. A historical overview of the original LLT is given, followed by a detailed description of the new ALDF systems and operational capabilities.

Davis, Pamela A.; Stubbs, Sandy M.; Tanner, John A.

1987-01-01

271

Multibody aircraft study, volume 1  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

272

The lift-fan aircraft: Lessons learned  

NASA Technical Reports Server (NTRS)

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

Deckert, Wallace H.

1995-01-01

273

Future Civil Aircraft and Technologies  

NASA Technical Reports Server (NTRS)

New aircraft technologies are presented that have the potential to expand the air transportation system and reduce congestion through new operating capabilities while also providing greater levels of safety and environmental compatibility. These new capabilities will result from current and planned civil aeronautics technology at the NASA Ames, Lewis, and Langley Research Centers and will cover the complete spectrum of current aircraft and new vehicle concepts including rotorcraft (helicopters and tilt rotors), vertical and short takeoff and landing (V/STOL), and short takeoff and landing (STOL) aircraft, subsonic transports, high-speed transports, and hypersonic/transatmospheric vehicles. New technologies will improve efficiency, affordability, safety, and environmental compatibility of current aircraft and will enable the development of new transportation system. The new capabilities of vehicles could lead to substantial market opportunities and economic growth and could improve the competitive position of the U.S. aerospace industry.

Albers, J.; Zuk, J.

1989-01-01

274

Towards Aerodynamic Shape Optimization of an Oblique Wing using the ADjoint Approach  

Microsoft Academic Search

Abstract The ADjoint method,is applied to a three-dimensional Computational Fluid Dynamics (CFD) solver to generate the sensitivities required for aerodynamic shape optimization. The ADjoint approach selectively uses Automatic Dierentiation,(AD) to generate the partial derivative terms in the discrete adjoint equations. By selectively applying AD techniques, the computational cost and memory overhead incurred by using AD are significantly reduced, while still

Charles A. Mader; Joaquim R. R. A. Martins

275

Subsonic Aircraft Safety Icing Study  

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

276

Aircraft turbofan noise  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

277

Structural integrity in aircraft.  

NASA Technical Reports Server (NTRS)

The paper reviews briefly the current design philosophies for achieving long, efficient, and reliable service in aircraft structures. The strengths and weaknesses of these design philosophies and their demonstrated records of success are discussed. The state of the art has not been developed to the point where designing can be done without major test inspection and maintenance programs. A broad program of research is proposed through which a viable computerized design scheme will be provided during the next decade. The program will organize and correlate existing knowledge on fatigue and fracture behavior, identify gaps in this knowledge, and guide specific research to upgrade design capabilities.

Hardrath, H. F.

1973-01-01

278

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

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

279

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

NASA Technical Reports Server (NTRS)

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

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

2014-01-01

280

Advanced structures technology and aircraft safety  

NASA Technical Reports Server (NTRS)

NASA research and development on advanced aeronautical structures technology related to flight safety is reviewed. The effort is categorized as research in the technology base and projects sponsored by the Aircraft Energy Efficiency (ACEE) Project Office. Base technology research includes mechanics of composite structures, crash dynamics, and landing dynamics. The ACEE projects involve development and fabrication of selected composite structural components for existing commercial transport aircraft. Technology emanating from this research is intended to result in airframe structures with improved efficiency and safety.

Mccomb, H. G., Jr.

1983-01-01

281

Aircraft systems cyber security  

Microsoft Academic Search

Presents a collection of slides from the author's conference presentation. Topics covered include: The Transition of Aircraft Systems; The Difference Between Cyber Security in Aircraft Systems and Information Technology (IT); Potential Cyber Security Threats to Aircraft Systems; and FAA Aircraft Systems Cyber Security Activities.

Raymond De Cerchio; Chris Riley

2012-01-01

282

The aircraft rotation problem  

Microsoft Academic Search

Given a set of flights to be flown for a specific aircraft type, with specified maintenance locations, durations, and needed frequency, the aircraft rotation problem is to determine the specific route flown by each aircraft. The objective is to maximize the benefit derived from making specific connections. In this paper, we present a mathematical formulation for the aircraft rotation problem

Lloyd Clarke; Ellis Johnson; George Nemhauser; Zhongxi Zhu

1997-01-01

283

To appear in the Journal of Geophysical Research, 1998, Version Date: September 30, 1998. Comparisons of aircraft, ship, and buoy meteorological  

E-print Network

. Comparisons of aircraft, ship, and buoy meteorological measurements from TOGA COARE Sean P. Burns, 1 Djamal measurements from buoys and ships, led to proposed offsets for the aircrafts' temperature, humidity data to the individual ship and buoy sensor heights for 264 over­flight comparisons. In addition, all

California at Irvine, University of

284

An aircraft sensor fault tolerant system  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

285

Aircraft Emissions at Cruise and Plume Processes  

NASA Astrophysics Data System (ADS)

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

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

286

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

NASA Technical Reports Server (NTRS)

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

Pinelli, Thomas E.; Golich, Vicki L.

1997-01-01

287

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

NASA Technical Reports Server (NTRS)

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

Golich, Vicki L.; Pinelli, Thomas E.

1997-01-01

288

Ball lightning risk to aircraft  

NASA Astrophysics Data System (ADS)

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

Doe, R.; Keul, A.

2009-04-01

289

Measurements of Lightning Strikes to Aircraft.  

National Technical Information Service (NTIS)

Sandia's primary interest in a joint thunderstorm research effort was in the effect of lightning on nuclear weapons and on aircraft and missile wiring. A description of the test instrumentation, its installation in the aircraft, and an analysis of the res...

B. J. Petterson, W. R. Wood

1968-01-01

290

Eclipse program QF-106 aircraft  

NASA Technical Reports Server (NTRS)

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

1996-01-01

291

Aircraft engine emission reduction  

SciTech Connect

The paper discusses new concepts for combustion chambers to help create low pollution power plants and reduce engine emissions. Researchers see that internal combustion engines provide complete combustion when they are close to stoichiometry while gas turbines experience problems when they reach this ratio. It would be best to modify the equivalence ratio of the primary combustion zone which is responsible for the high level of NOx emissions. Reduction of pollutant emissions from aircraft engines are focused on three areas: (1) use of less polluting fuels; (2) modification of the combustion process; and (3) reduction of specific fuel consumption and consequently consumption overall.

Birch, S.

1994-01-01

292

Hypersonic transport aircraft  

NASA Technical Reports Server (NTRS)

A hypersonic transport aircraft design project was selected as a result of interactions with NASA Lewis Research Center personnel and fits the Presidential concept of the Orient Express. The Graduate Teaching Assistant (GTA) and an undergraduate student worked at the NASA Lewis Research Center during the 1986 summer conducting a literature survey, and relevant literature and useful software were collected. The computer software was implemented in the Computer Aided Design Laboratory of the Mechanical and Aerospace Engineering Department. In addition to the lectures by the three instructors, a series of guest lectures was conducted. The first of these lectures 'Anywhere in the World in Two Hours' was delivered by R. Luidens of NASA Lewis Center. In addition, videotaped copies of relevant seminars obtained from NASA Lewis were also featured. The first assignment was to individually research and develop the mission requirements and to discuss the findings with the class. The class in consultation with the instructors then developed a set of unified mission requirements. Then the class was divided into three design groups (1) Aerodynamics Group, (2) Propulsion Group, and (3) Structures and Thermal Analyses Group. The groups worked on their respective design areas and interacted with each other to finally come up with an integrated conceptual design. The three faculty members and the GTA acted as the resource persons for the three groups and aided in the integration of the individual group designs into the final design of a hypersonic aircraft.

1987-01-01

293

Innovative Materials for Aircraft Morphing  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

294

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

NASA Technical Reports Server (NTRS)

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

Schultz, James

2003-01-01

295

Multidisciplinary Techniques and Novel Aircraft Control Systems  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

296

Effect of rotor wake on aerodynamic characteristics of a 1/6 scale model of the rotor systems research aircraft. [in the Langley V/STOL tunnel  

NASA Technical Reports Server (NTRS)

Tests were conducted in the Langley V/STOL tunnel to determine the effect of the main-rotor wake on the aerodynamic characteristics of the rotor systems research aircraft. A 1/6-scale model with a 4-blade articulated rotor was used to determine the effect of the rotor wake for the compound configuration. Data were obtained over a range of angles of attack, angles of sideslip, auxiliary engine thrusts, rotor collective pitch angles, and rotor tip-path plane angles for several main-rotor advance ratios. Separate results are presented for the forces and moments on the airframe, the wing, and the tail. An analysis of the test data indicates significant changes in the aerodynamic characteristics. The rotor wake increases the longitudinal static stability, the effective dihedral, and the lateral static stability of the airframe. The rotor induces a downwash on the wing. This downwash decreases the wing lift and increases the drag. The asymmetrical rotor wake induces a differential lift across the wing and a subsequent rolling moment. These rotor induced effects on the wing become smaller with increasing forward speed.

Mineck, R. E.

1977-01-01

297

Static and transient performance of YF-102 engine with up to 14 percent core airbleed for the quiet short-haul research aircraft  

NASA Technical Reports Server (NTRS)

An outdoor static test stand was used to measure the steady-state and transient performance of the YF-102 turbofan engine with core airbleed. The test configuration included a bellmouth inlet and a confluent-flow exhaust system similar in size to the quiet short-haul research aircraft (QSRA) exhaust system. For the steady-state tests, the engine operated satisfactorily with core bleed up to 14 percent of the core inlet flow. For the transient tests the engine accelerated and decelerated satisfactorily with no core bleed and with core bleed up to 11 percent of the core inlet flow (maximum tested). For some of the tests the core-bleed flow rate was scheduled to vary with fan discharge pressure, to simulate the QSRA bleed requirements. No stability, surge, stall, overtemperature, combustor flameout, or other operating problems were encountered in any of the tests. Steady-state and transient engine performance data are presented in graphs, and fuel-control trajectories for typical transient tests are shown.

Mcardle, J. G.; Homyak, L.; Moore, A. S.

1980-01-01

298

Combining active and passive remote sensing from research aircraft with atmospheric models to evaluate NOx emission fluxes and O3 formation in the Los Angeles Megacity  

NASA Astrophysics Data System (ADS)

Ozone (O3) and nitrogen dioxide (NO2) are two important components of air pollution. We have measured vertical column amounts of NO2, and vertical profiles of O3 and wind speed by means of measurements of solar stray light by CU Airborne MAX-DOAS, and active remote sensing using the NOAA TOPAZ lidar, and the University of Leeds Doppler lidar aboard the NOAA Twin Otter research aircraft. A total of 52 flights (up to 4 hours each) were carried out between May 19 and July 19 2010 during the CalNex and CARES field campaigns. These flights cover most of California. The boundary layer height was measured by TOPAZ lidar, and trace gas concentrations of NO2 and O3 were integrated over boundary layer height. These column integrated quantities are then combined with direct wind speed measurements to quantify directly the pollutant flux across the boundary, as defined by the flight track. By tracking the pollution fluxes during transects that are flown upwind and in various distances downwind of a NOx emission source, the NOx emission rate, and the ozone formation rate are quantified. These pollutant fluxes are calculated here for the first time exclusively based on measurements (i.e., without need to infer wind speed from a model). These fluxes provide constraints to quantify localized NOx emissions, and are being compared with WRF-Chem model simulations.

Baidar, Sunil; Oetjen, Hilke; Senff, Christoph; Alvarez, Raul, II; Hardesty, Michael; Langford, Andrew; Kim, Si-Wan; Trainer, Michael; Volkamer, Rainer

2013-04-01

299

Unmanned Aircraft Systems for Communication and Atmospheric Sensing Missions  

E-print Network

Unmanned Aircraft Systems for Communication and Atmospheric Sensing Missions Eric W. Frew, Brian Argrow, Dale Lawrence, Jack Elston, and Maciej Stachura, Research and Engineering Center for Unmanned and Engineer- ing Center for Unmanned Vehicles Heterogeneous Unmanned Aircraft System. The unmanned aircraft

Frew, Eric W.

300

NASA progress in aircraft noise prediction  

NASA Technical Reports Server (NTRS)

Langley Research Center efforts to develop a methodology for predicting the effective perceived noise level (EPNL) produced by jet-powered CTOL aircraft to an accuracy of + or - 1.5 dB are summarized with emphasis on the aircraft noise prediction program (ANOPP) which contains a complete set of prediction methods for CTOL aircraft including propulsion system noise sources, aerodynamic or airframe noise sources, forward speed effects, a layered atmospheric model with molecular absorption, ground impedance effects including excess ground attenuation, and a received noise contouring capability. The present state of ANOPP is described and its accuracy and applicability to the preliminary aircraft design process is assessed. Areas are indicated where further theoretical and experimental research on noise prediction are needed. Topics covered include the elements of the noise prediction problem which are incorporated in ANOPP, results of comparisons of ANOPP calculations with measured noise levels, and progress toward treating noise as a design constraint in aircraft system studies.

Raney, J. P.; Padula, S. L.; Zorumski, W. E.

1981-01-01

301

Aircraft measurements and coordination in FASINEX  

NASA Astrophysics Data System (ADS)

As of July 10, 1985, the following progress was made on the proposal work: (1) wind and turbulence measurements on NRL Navy RP3A aircraft, BUNO 149670: (a) Radome pressure transducers purchased and installed with radome tubing, and wiring, test flights were performed to determine if pressure signals are active, (b) data system for aircraft tested, borrowed from National Center for Atmospheric Research (NCAR), Boulder, Colorado and shipped to NRL and made operational in the laboratory; (c) various environmental sensors obtained from USN China Lake, CA, for the NRL RP3A: Barnes infrared meterological radiometers; parts of dew point system; (2) FASINEX Aircraft Coordination: (a) site visit made to NAS Bermuda, facilities will be provided for transient FASINEX aircraft by NAS Bermuda; (b) cooperative agreement for joint use of NCAR Electra research aircraft by GALE and FASINEX projects worked out; (c) attended GALE planning meeting as FASINEX representative.

Friehe, C.

1985-07-01

302

GaAs/Ge Solar Powered Aircraft  

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

303

Propulsion controlled aircraft computer  

NASA Technical Reports Server (NTRS)

A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

Cogan, Bruce R. (Inventor)

2010-01-01

304

Alternate Fuels for Use in Commercial Aircraft  

NASA Technical Reports Server (NTRS)

The engine and aircraft Research and Development (R&D) communities have been investigating alternative fueling in near-term, midterm, and far-term aircraft. A drop in jet fuel replacement, consisting of a kerosene (Jet-A) and synthetic fuel blend, will be possible for use in existing and near-term aircraft. Future midterm aircraft may use a biojet and synthetic fuel blend in ultra-efficient airplane designs. Future far-term engines and aircraft in 50-plus years may be specifically designed to use a low- or zero-carbon fuel. Synthetic jet fuels from coal, natural gas, or other hydrocarbon feedstocks are very similar in performance to conventional jet fuel, yet the additional CO2 produced during the manufacturing needs to be permanently sequestered. Biojet fuels need to be developed specifically for jet aircraft without displacing food production. Envisioned as midterm aircraft fuel, if the performance and cost liabilities can be overcome, biofuel blends with synthetic jet or Jet-A fuels have near-term potential in terms of global climatic concerns. Long-term solutions address dramatic emissions reductions through use of alternate aircraft fuels such as liquid hydrogen or liquid methane. Either of these new aircraft fuels will require an enormous change in infrastructure and thus engine and airplane design. Life-cycle environmental questions need to be addressed.

Daggett, David L.; Hendricks, Robert C.; Walther, Rainer; Corporan, Edwin

2008-01-01

305

Commercial aircraft fuel efficiency potential through 2010  

SciTech Connect

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

Greene, D.L.

1990-01-01

306

V/STOL aircraft concepts  

NASA Technical Reports Server (NTRS)

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

1987-01-01

307

Altus aircraft on runway  

NASA Technical Reports Server (NTRS)

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

1996-01-01

308

Dynamic properties of aircraft tires  

NASA Technical Reports Server (NTRS)

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

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

1974-01-01

309

AIRCRAFT DEPAINTING TECHNOLOGY  

EPA Science Inventory

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

310

A NOTE ON LIGHTNING STRIKES TO AIRCRAFT  

E-print Network

A DC-6 research aircraft was struck by lightning on three occasions during a thunderstorm research project at Flagstaff, Aria., in July 1967. Electric fields and meteorological parameters were measured and recorded. Similar conditions existed at the time of the lightning strikes. Each event occurred in a dissipating cumulonimbus, near the freezing level and in a region containing both ice and water. Corona discharge from the aircraft occurred prior to each strike. The possibility exists that one or more of the lightning strikes were triggered by the aircraft.

November William E. Cobb; F. James Holitza; William E. Cobb; F. James Holitza

311

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

NASA Astrophysics Data System (ADS)

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

Yavuz, Murat; Akkas, Ali; Aslan, Yavuz

2012-06-01

312

Aircraft flight test trajectory control  

NASA Technical Reports Server (NTRS)

Two control law design techniques are compared and the performance of the resulting controllers evaluated. The design requirement is for a flight test trajectory controller (FTTC) capable of closed-loop, outer-loop control of an F-15 aircraft performing high-quality research flight test maneuvers. The maneuver modeling, linearization, and design methodologies utilized in this research, are detailed. The results of applying these FTTCs to a nonlinear F-15 simulation are presented.

Menon, P. K. A.; Walker, R. A.

1988-01-01

313

Aircraft and air pollution  

SciTech Connect

The Clean Air Act of 1977 directs EPA to issue emission standards for aircraft engines that may contribute to air pollution and thus endanger public health or welfare. Critics argue that the regulations are overly complex and stringent, and that immediate energy shortages may take precedence over the need for aircraft emission controls. Proponents of the regulations claim that ambient air standards are freqeuntly violated and will continue to be unless the best available control technology is applied to all sources, including aircraft. The contribution of aircraft to total emissions is discussed. Engineering problems and costs of retrofitting pollution controls on aircrafts are examined.

Naugle, D.F.; Fox, D.L.

1981-04-01

314

Aircraft Lightning Electromagnetic Environment Measurement  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

315

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

NASA Technical Reports Server (NTRS)

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

Kelly, Michael J.

2013-01-01

316

Conceptual aircraft dynamics from inverse aircraft modeling  

E-print Network

on which to test their control laws. The method involves the extraction of the aerodynamic and propulsive data from the existing simulation and their subsequent integration into a new nonlinear simulation. The subject aircraft from which the data is derived...

Ziegler, Gregory E

2012-06-07

317

Laser Powered Aircraft Takes Flight  

NASA Technical Reports Server (NTRS)

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

2003-01-01

318

Low Reynolds number, long endurance aircraft design  

SciTech Connect

Airplanes are typically designed to maximize range at the highest practical cruising speed. However, several missions require extended duration rather than range, and favor the slowest possible cruise speed. Such missions include surveillance, radio relay, and ship's electronic decoy. These missions are ideally suited for advanced technology unmanned aircraft, either remotely piloted or autonomous. Feasibility studies have been conducted and flight demonstrator prototypes of such unique aircraft have been under steady research and development at the Naval Research Laboratory since 1978. This paper discusses the design aspects and tradeoffs unique to small, slow speed long endurance unmanned aircraft operating at wing chord Reynolds numbers between 150,000 and 500,000. Additionally, many of these low Reynolds number-driven design features have applicability to high altitude, long endurance aircraft. 6 refs.

Foch, R.J.; Ailinger, K.G. (U.S. Navy, Naval Research Laboratory, Washington, DC (United States))

1992-02-01

319

Daedalus Project's Light Eagle - Human powered aircraft  

NASA Technical Reports Server (NTRS)

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

1987-01-01

320

Lightning effects on aircraft  

NASA Technical Reports Server (NTRS)

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

1977-01-01

321

Tilt Rotor Aircraft Aeroacoustics  

NASA Technical Reports Server (NTRS)

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

George, Albert R.

1996-01-01

322

Hypersonic aircraft design  

NASA Technical Reports Server (NTRS)

A hypersonic aircraft is designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and it was decided that the aircraft would use one full scale turbofan-ramjet. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic region. After considering aerodynamics, aircraft design, stability and control, cooling systems, mission profile, and landing systems, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets are also taken into consideration in the final design. A hypersonic aircraft was designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and a full scale turbofan-ramjet was chosen. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic reqion. After the aerodynamics, aircraft design, stability and control, cooling systems, mission profile, landing systems, and their physical interactions were considered, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets were also considered in the designing process.

Alkamhawi, Hani; Greiner, Tom; Fuerst, Gerry; Luich, Shawn; Stonebraker, Bob; Wray, Todd

1990-01-01

323

Interactive dynamic aircraft scheduling  

E-print Network

Introducing recent advances in computer technology to improve aircraft scheduling is investigated. Incorporating interactive graphics, modern database manipulation techniques, and decision support algorithms, the computer ...

Deckwitz, Thomas Anthony

1984-01-01

324

Vision-based aircraft guidance  

NASA Technical Reports Server (NTRS)

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

Menon, P. K.

1993-01-01

325

Innovations in Aircraft Design  

NASA Technical Reports Server (NTRS)

The Boeing 777 carries with it basic and applied research, technology, and aerodynamic knowledge honed at several NASA field centers. Several Langley Research Center innovations instrumental to the development of the aircraft include knowledge of how to reduce engine and other noise for passengers and terminal residents, increased use of lightweight aerospace composite structures for increased fuel efficiency and range, and wind tunnel tests confirming the structural integrity of 777 wing-airframe integration. Test results from Marshall Space Flight Center aimed at improving the performance of the Space Shuttle engines led to improvements in the airplane's new, more efficient jet engines. Finally, fostered by Ames Research Center, the Boeing 777 blankets that protect areas of the plane from high temperatures and fire have a lineage to Advanced Flexible Reusable Surface Insulation used on certain areas of the Space Shuttle. According to Boeing Company estimates, the 777 has captured three-quarters of new orders for airplanes in its class since the program was launched.

1997-01-01

326

Application of advanced technology to future long-range aircraft  

NASA Technical Reports Server (NTRS)

The objective of this paper is to provide an overview assessment of three separate programs at Langley Research Center that have incorporated advanced technology into the design of long-range passenger and cargo aircraft. The first technology centers around the use of an span-loaded cargo aircraft with the payload distributed along the wing. This concept has the potential for reduced structural weights. The second technology is the application of laminar flow control (LFC) to the aircraft to reduce the aerodynamic drag. The use of LFC can reduce the fuel requirements during long-range cruise. The last program evaluates the production of alternate aircraft fuels from coal and the use of liquid hydrogen as an aircraft fuel. Coal-derived hydrogen as an aircraft fuel offers both the prospect for reduced dependence on petroleum fuels and improved performance for long-range aircraft.

Schrader, O. E.

1976-01-01

327

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

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

328

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

NASA Technical Reports Server (NTRS)

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

Pines, S.

1982-01-01

329

Nondestructive inspection of bonded composite doublers for aircraft  

Microsoft Academic Search

One of the major thrusts established under the FAA's National Aging Aircraft Research Program is to foster new technologies associated with civil aircraft maintenance. Recent DOD and other government developments in the use of bonded composite doublers on metal structures has supported the need for research and validation of such doubler applications on US certificated airplanes. Composite doubler technology is

Dennis Roach; David Moore; Phil Walkington

1996-01-01

330

Modeling Programs Increase Aircraft Design Safety  

NASA Technical Reports Server (NTRS)

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

2012-01-01

331

Leading the way in aircraft noise reduction Aircraft noise threatens the growth of the important UK aerospace manufacturing sector.  

E-print Network

collaboration with Southampton's Institute of Sound and Vibration Research (ISVR) on aircraft engine noise working on aircraft noise at any one time. Southampton is also the `UK focal point' for the X causes of noise have been identified and research has been carried out to reduce their effect. Sound

Sóbester, András

332

General Aviation Aircraft Reliability Study  

NASA Technical Reports Server (NTRS)

This reliability study was performed in order to provide the aviation community with an estimate of Complex General Aviation (GA) Aircraft System reliability. To successfully improve the safety and reliability for the next generation of GA aircraft, a study of current GA aircraft attributes was prudent. This was accomplished by benchmarking the reliability of operational Complex GA Aircraft Systems. Specifically, Complex GA Aircraft System reliability was estimated using data obtained from the logbooks of a random sample of the Complex GA Aircraft population.

Pettit, Duane; Turnbull, Andrew; Roelant, Henk A. (Technical Monitor)

2001-01-01

333

Lightning protection for aircraft  

NASA Technical Reports Server (NTRS)

Reference book summarizes current knowledge concerning potential lightning effects on aircraft and means available to designers and operators to protect against effects. Book is available because of increasing use of nonmetallic materials in aircraft structural components and use of electronic equipment for control of critical flight operations and navigation.

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

1980-01-01

334

Lightning protection of aircraft  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

335

Civil aircraft accident investigation.  

PubMed

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

Haines, Daniel

2013-01-01

336

Aircraft and air pollution  

Microsoft Academic Search

The Clean Air Act of 1977 directs EPA to issue emission standards for aircraft engines that may contribute to air pollution and thus endanger public health or welfare. Critics argue that the regulations are overly complex and stringent, and that immediate energy shortages may take precedence over the need for aircraft emission controls. Proponents of the regulations claim that ambient

Dennis F. Naugle; Donald L. Fox

1981-01-01

337

Solar powered aircraft  

Microsoft Academic Search

A cruciform wing structure for a solar powered aircraft is disclosed. Solar cells are mounted on horizontal wing surfaces. Wing surfaces with spanwise axis perpendicular to surfaces maintain these surfaces normal to the sun's rays by allowing aircraft to be flown in a controlled pattern at a large bank angle. The solar airplane may be of conventional design with respect

1983-01-01

338

Solar thermal aircraft  

Microsoft Academic Search

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

Charles L

2007-01-01

339

Cable Tensiometer for Aircraft  

NASA Technical Reports Server (NTRS)

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

Nunnelee, Mark (Inventor)

2008-01-01

340

Historical development of worldwide supersonic aircraft  

NASA Technical Reports Server (NTRS)

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

Spearman, M. L.

1979-01-01

341

Health monitoring aircraft  

SciTech Connect

A description is given of the health monitoring aircraft concept, which will incorporate innovative sensors, AI, and advanced analytical techniques to provivide real-time and continual aircraft health assessment. According to this concept, all flight-critical structures will be evaluated for integrity as part of the automated preflight checklist. The pilot will be given a visual display of the health of all systems prior to takeoff. Any in-flight change in the health of the aircraft wil be displayed along with recommended action. In order to achieve these capabilities, state-of-the-art structural integrity computer programs, together with AI/neutral network decision-making software, will be incorporated as part of the aircraft computing capability. The life history of the aircraft will be continually and automaticaly updated so that acccurate structural integrity assessments can be made.

Gerardi, T.G. (USAF, Wright Research and Development Center, Wright-Patterson AFB, OH (USA))

1990-07-01

342

Fluidic Emergency Thruster for Aircraft  

NASA Technical Reports Server (NTRS)

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

Honda, T. S.

1972-01-01

343

B-52 Launch Aircraft in Flight  

NASA Technical Reports Server (NTRS)

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

2001-01-01

344

Modeling interactions of aircraft emissions with global and regional atmospheric chemistry and climate  

Microsoft Academic Search

Aircraft engines emit a variety of chemical compounds that affect atmospheric chemistry and climate. In the research presented here, we have addressed three different issues related to aircraft emissions. The first phase of the research has two parts. In the first part, we have analyzed the effects of potential fleets of aircraft on atmospheric ozone concentrations. We have used a

Mayurakshi Dutta

2006-01-01

345

Pulse Doppler signature of a rotary-wing aircraft  

Microsoft Academic Search

A measurement research program was conducted to investigate rotary-wing aircraft Doppler radar signature phenomenology. Results of the data analysis program are presented with regard to classification and identification of a rotary-wing aircraft based on its Doppler radar signature. Using the return from a Doppler radar and appropriate frequency-domain signal-processing techniques, a rotary-wing aircraft's design, such as main rotor configuration (single,

B. D. Bullard; P. C. Dowdy

1991-01-01

346

Multidisciplinary design optimization of low-noise transport aircraft  

Microsoft Academic Search

The objective of this research is to examine how to design low-noise transport aircraft using Multidisciplinary Design Optimization (MDO). The subject is approached by designing for low-noise both implicitly and explicitly. The explicit design approach involves optimizing an aircraft while explicitly constraining the noise level. An MDO framework capable of optimizing both a cantilever wing and a Strut-Braced-Wing (SBW) aircraft

Leifur Thor Leifsson

2006-01-01

347

Jet aircraft emissions during cruise: Present and future  

NASA Technical Reports Server (NTRS)

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

Grobman, J. S.

1975-01-01

348

The atmospheric effects of stratospheric aircraft  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

349

The impact of aircraft design reference mission on fuel efficiency in the air transportation system  

E-print Network

Existing commercial aircraft are designed for high mission flexibility, which results in decreased fuel efficiency throughout the operational life of an aircraft. The objective of this research is to quantify the impact ...

Yutko, Brian M. (Brian Matthew)

2014-01-01

350

Tropospheric sampling with aircraft  

SciTech Connect

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

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

1991-03-01

351

Aircraft compass characteristics  

NASA Technical Reports Server (NTRS)

A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Characteristics of Navy aircraft compasses IV to IX and some other compasses are shown for the range of temperatures experienced in flight. Results of flight tests are presented. These results indicate that the characteristic most desired in a steering compass is a short period and, in a check compass, a low overswing.

Peterson, John B; Smith, Clyde W

1937-01-01

352

Flow simulation for aircraft  

NASA Astrophysics Data System (ADS)

The various aspects of computer simulation of flow about aircrafts, and their role in aircraft design are discussed. The general tendency in the industrial development process to accelerate product innovation by an integrated approach to the design is explained. Experimental wind tunnel investigations and mathematical modeling are discussed as the two available methods for the analysis of flow about aircrafts. The various flow models used in flow simulation are discussed in successive order of decreasing complexity, and their applicability is outlined. The successive steps in flow simulation are presented. The state of the art in relation to computer technology is described. Information aspects of simulation are discussed in general terms.

Loeve, W.; Vandervooren, J.

1987-12-01

353

Stochastic Methods for Aircraft Design  

NASA Technical Reports Server (NTRS)

The global stochastic optimization method, simulated annealing (SA), was adapted and applied to various problems in aircraft design. The research was aimed at overcoming the problem of finding an optimal design in a space with multiple minima and roughness ubiquitous to numerically generated nonlinear objective functions. SA was modified to reduce the number of objective function evaluations for an optimal design, historically the main criticism of stochastic methods. SA was applied to many CFD/MDO problems including: low sonic-boom bodies, minimum drag on supersonic fore-bodies, minimum drag on supersonic aeroelastic fore-bodies, minimum drag on HSCT aeroelastic wings, FLOPS preliminary design code, another preliminary aircraft design study with vortex lattice aerodynamics, HSR complete aircraft aerodynamics. In every case, SA provided a simple, robust and reliable optimization method which found optimal designs in order 100 objective function evaluations. Perhaps most importantly, from this academic/industrial project, technology has been successfully transferred; this method is the method of choice for optimization problems at Northrop Grumman.

Pelz, Richard B.; Ogot, Madara

1998-01-01

354

Heat management system for aircraft  

Microsoft Academic Search

A novel heat management system for aircraft is provided which is based on the aircraft fuel as the heat exchange medium and comprises a dedicated thermal reserves fuel tank for containing refrigerated aircraft fuel (or other expendable liquid) which is cooled by heat exchange with the primary aircraft fuel flow to the engines; a fuel line loop for conducting fuel

1983-01-01

355

Automated Methods to Maintain Aircraft Separation  

NASA Technical Reports Server (NTRS)

The air traffic control system in the United States has a great track-record for safety. As more aircraft enter the system at a given time, the situation becomes more complex though. Researchers at NASA are attempting to leverage advances in many fields including optimization, data mining, and numerical modeling of systems to improve the air-transportation system maintaining safety while increasing throughput and reducing delays. This talk will give a brief overview of the research at NASA towards modernizing the air-transportation system. It will then focus on the specific area of automation tools for maintaining physical separation between aircraft known as Separation Assurance.

Lauderdale, Todd

2011-01-01

356

Takeoff predictions for powered-lift aircraft. Thesis  

NASA Technical Reports Server (NTRS)

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

Wardwell, Douglas A.; Sandlin, Doral R.

1988-01-01

357

Aircraft parameter estimation  

NASA Technical Reports Server (NTRS)

The aircraft parameter estimation problem is used to illustrate the utility of parameter estimation, which applies to many engineering and scientific fields. Maximum likelihood estimation has been used to extract stability and control derivatives from flight data for many years. This paper presents some of the basic concepts of aircraft parameter estimation and briefly surveys the literature in the field. The maximum likelihood estimator is discussed, and the basic concepts of minimization and estimation are examined for a simple simulated aircraft example. The cost functions that are to be minimized during estimation are defined and discussed. Graphic representations of the cost functions are given to illustrate the minimization process. Finally, the basic concepts are generalized, and estimation from flight data is discussed. Some of the major conclusions for the simulated example are also developed for the analysis of flight data from the F-14, highly maneuverable aircraft technology (HiMAT), and space shuttle vehicles.

Iliff, Kenneth W.

1987-01-01

358

Aircraft Engine Emissions. [conference  

NASA Technical Reports Server (NTRS)

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

1977-01-01

359

Laminar Flow Aircraft Certification  

NASA Technical Reports Server (NTRS)

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

Williams, Louis J. (compiler)

1986-01-01

360

Pollution reducing aircraft propulsion  

Microsoft Academic Search

Aircraft engine exhaust is mixed with air and fuel and recombusted. Air is drawn into the secondary combustion chamber from suction surfaces on wings. Exhaust of the secondary combustion chamber is blown over wing and fuselage surfaces.

Tamura

1985-01-01

361

Pollution reducing aircraft propulsion  

SciTech Connect

Aircraft engine exhaust is mixed with air and fuel and recombusted. Air is drawn into the secondary combustion chamber from suction surfaces on wings. Exhaust of the secondary combustion chamber is blown over wing and fuselage surfaces.

Tamura, R. M.

1985-05-28

362

Solar thermal aircraft  

SciTech Connect

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Bennett, Charles L. (Livermore, CA)

2007-09-18

363

Aircraft Laminar Flow Control  

Microsoft Academic Search

Aircraft laminar flow control (LFC) from the 1930s through the 1990s is reviewed and the current status of the technology is assessed. Examples are provided to demonstrate the benefits of LFC for subsonic and supersonic aircraft. Early studies related to the laminar boundary-layer flow physics, manufacturing tolerances for laminar flow, and insect-contamination avoidance are discussed. LFC concept studies in wind-tunnel

Ronald D. Joslin

1998-01-01

364

Alternative jet aircraft fuels  

NASA Technical Reports Server (NTRS)

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

Grobman, J.

1979-01-01

365

Characterizations of Aircraft Icing Environments that Include Supercooled Large Drops  

Microsoft Academic Search

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

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

2001-01-01

366

CHARBEL FARHAT Vivian Church Hoff Professor of Aircraft Structures  

E-print Network

CHARBEL FARHAT Vivian Church Hoff Professor of Aircraft Structures Chairman, Aeronautics@stanford.edu BIOSKETCH Charbel Farhat is the Vivian Church Hoff Professor of Aircraft Structures at Stanford University Bureau of Industry and Security's Emerging Technology and Research Advisory Committee (ETRAC

Farhat, Charbel

367

Formal Methods for the Certification of Autonomous Unmanned Aircraft Systems  

E-print Network

Formal Methods for the Certification of Autonomous Unmanned Aircraft Systems Matt Webster1, for the certification of Unmanned Aircraft Systems (UAS) within civil airspace. We begin by modelling a basic UAS certification, and present directions for future research. Keywords: Model Checking, Formal Methods, Unmanned

Fisher, Michael

368

Model Checking and the Certification of Autonomous Unmanned Aircraft Systems  

E-print Network

Model Checking and the Certification of Autonomous Unmanned Aircraft Systems Matt Webster1, Michael the feasibility of using formal methods, and model checking in particular, within the certification of Unmanned directions for future research. 1 Introduction An Unmanned Aircraft System (UAS, plural UAS) is a group

Atkinson, Katie

369

Framework for the Conceptual Decomposition of Unmanned Aircraft Propulsion Systems  

Microsoft Academic Search

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

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

2008-01-01

370

Review of subjective measures of human response to aircraft noise  

NASA Technical Reports Server (NTRS)

The development of aircraft noise rating scales and indexes is reviewed up to the present time. Single event scales, multiple event indexes, and their interrelation with each other, are considered. Research requirements for further refinement and development of aircraft noise rating quantification factors are discussed.

Cawthorn, J. M.; Mayes, W. H.

1976-01-01

371

Wearable Computing for Aircraft Maintenance: Simplifying the User Interface  

Microsoft Academic Search

In this paper we present results from the realization of a wearable computing system with the goal to shorten the maintenance process in the aircraft industry. The project combines knowledge manage- ment with wearable computing to enable instant access to an electronic logbook, aircraft manuals, and experience knowledge. This research is part of an ongoing project which is carried out

Tom Nicolai; Thomas Sindt; Hendrik Witt; Jorn Reimerdes; Holger Kenn

2006-01-01

372

Case Study of Wearable Computing for Aircraft Maintenance  

Microsoft Academic Search

In this paper we present a concept for a combination of wear- able computing and knowledge management with the goal to shorten the maintenance process in the aircraft industry. This research is part of an ongoing project which is carried out in cooperation with an aircraft com- pany. This paper describes the functions of the wearable devices as well as

Tom Nicolai; Thomas Sindt; Holger Kenn; Hendrik Witt

2005-01-01

373

Eclipse program C-141A aircraft  

NASA Technical Reports Server (NTRS)

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

1997-01-01

374

Pathfinder aircraft being assembled - wing assembly  

NASA Technical Reports Server (NTRS)

Technicians easily lift a 20-foot-long wing section during assembly of the Pathfinder solar-powered research aircraft at NASA's Dryden Flight Research Center, Edwards, California. A number of upgrades were made to the unique aircraft prior to its successful checkout flight Nov. 19, 1996, among them the installation of stronger ultra-light wing ribs made of composite materials on two of the five wing panels. 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.)

1996-01-01

375

Cyberinfrastructure for Aircraft Mission Support  

NASA Technical Reports Server (NTRS)

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

Freudinger, Lawrence C.

2010-01-01

376

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

NASA Technical Reports Server (NTRS)

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

Jacklin, Stephen A.; Schumann, Johann; Guenther, Kurt; Bosworth, John

2006-01-01

377

NASA research in aeropropulsion  

SciTech Connect

Future advances in aircraft propulsion systems will be aided by the research performed by NASA and its contractors. This paper gives selected examples of recent accomplishments and current activities relevant to the principal classes of civil and military aircraft. Some instances of new emerging technologies with potential high impact on further progress are discussed. NASA research described includes noise abatement and fuel economy measures for commercial subsonic, supersonic, commuter, and general aviation aircraft, aircraft engines of the jet, turboprop, diesel and rotary types, VTOL, X-wing rotocraft, helicopters, and ''stealth'' aircraft. Applications to military aircraft are also discussed.

Stewart, W.L.; Weber, R.J.

1981-12-01

378

Observing Supercells with Unmanned Aircraft: Results from the UAS Component of VORTEX2  

Microsoft Academic Search

In the second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX-2) autonomous unmanned aircraft were used for the first time to collect in-situ observations in close proximity to supercells. The use of unmanned aircraft to collect data significant to stormscale research has long been recognized. However, collecting these data requires aircraft operation beyond the visual line of sight

A. L. Houston; B. Argrow; E. Frew

2010-01-01

379

Aerodynamically Optimal Regional Aircraft Concepts: Conventional and Blended Wing-Body Designs  

E-print Network

Aerodynamically Optimal Regional Aircraft Concepts: Conventional and Blended Wing-Body Designs in efficient aircraft design, yet little work has explored the applicability of this design concept to small and Director, Canada Research Chair in Computational Aerodynamics and Environmentally Friendly Aircraft Design

Zingg, David W.

380

Multidisciplinary aircraft design and evaluation software integrating CAD, analysis, database, and optimization  

Microsoft Academic Search

The development of an overall strategy to design the aircraft using analysis codes is presented. The procedure is automated through the integrated software MADE (multidisciplinary aircraft design and evaluation) developed in this research that enables the determination of an optimum set of aircraft configurations. The core ingredients of MADE are (i) analysis codes, which utilizes initial sizing, aerodynamics, mass, stability

H. Y. Hwang; K. J. Jung; I. M. Kang; M. S. Kim; S. I. Park; J. H. Kim

2006-01-01

381

Aircraft Accident Prevention: Loss-of-Control Analysis Harry G. Kwatny  

E-print Network

Aircraft Accident Prevention: Loss-of-Control Analysis Harry G. Kwatny , Jean-Etienne T. Dongmo NASA Langley Research Center, MS 161, Hampton, VA, 23681. The majority of fatal aircraft accidents that during the ten year period 1997-2006, 59% of fatal aircraft accidents were associated with Loss

Kwatny, Harry G.

382

A branch-and-price approach for operational aircraft maintenance routing  

Microsoft Academic Search

In recent years, considerable effort in the field of operations research has been paid to optimizing airline operations, including the logistics of an airline’s fleet of aircraft. We focus on the problem of aircraft routing, which involves generating and selecting a particular route for each aircraft of a sub-fleet that is already assigned to a set of feasible sequences of

Abdulkadir Sarac; Rajan Batta; Christopher M. Rump

2006-01-01

383

Automated NonDestructive Inspector of Aging Aircraft Ian Davis and M. W. Siegel  

E-print Network

attached to a safety-tether that hangs from the safety-rail above each aircraft in the maintenance hangarAutomated NonDestructive Inspector of Aging Aircraft Ian Davis and M. W. Siegel The Robotics the FAA Aging Aircraft Research program (grant # G0319014) we are developing robots to deploy conventional

Siegel, Mel

384

Field Results of a GPS/INS-Based Approach to Measuring Ship Flexure Onboard an Aircraft  

E-print Network

extensively on the integration of GPS and inertial navigation systems for precise aircraft positioning. Dr navigation since 1998. He major research interests have been in GNSS system simulation and assessment, space and Landing System (JPALS) aims to deliver automatic landing capabilities to inbound aircraft aboard aircraft

Calgary, University of

385

Research and technology of the Langley Research Center  

NASA Technical Reports Server (NTRS)

Descriptions of the research and technology activities at the Langley Research Center are given. Topics include laser development, aircraft design, aircraft engines, aerodynamics, remote sensing, space transportation systems, and composite materials.

1980-01-01

386

Ultrasonic Measurement of Aircraft Strut Hydraulic Fluid Level  

NASA Technical Reports Server (NTRS)

An ultrasonic method is presented for non-intrusively measuring hydraulic fluid level in aircraft struts in the field quickly and easily without modifying the strut or aircraft. The technique interrogates the strut with ultrasonic waves generated and received by a removable ultrasonic transducer hand-held on the outside of the strut in a fashion that is in the presence or absence of hydraulic fluid inside the strut. This technique was successfully demonstrated on an A-6 aircraft strut on the carriage at the Aircraft Landing Dynamics Research Facility at NASA Langley Research Center. Conventional practice upon detection of strut problem symptoms is to remove aircraft from service for extensive maintenance to determine fluid level. No practical technique like the method presented herein for locating strut hydraulic fluid level is currently known to be used.

Allison, Sidney G.

2002-01-01

387

Aircraft noise synthesis system  

NASA Technical Reports Server (NTRS)

A second-generation Aircraft Noise Synthesis System has been developed to provide test stimuli for studies of community annoyance to aircraft flyover noise. The computer-based system generates realistic, time-varying, audio simulations of aircraft flyover noise at a specified observer location on the ground. The synthesis takes into account the time-varying aircraft position relative to the observer; specified reference spectra consisting of broadband, narrowband, and pure-tone components; directivity patterns; Doppler shift; atmospheric effects; and ground effects. These parameters can be specified and controlled in such a way as to generate stimuli in which certain noise characteristics, such as duration or tonal content, are independently varied, while the remaining characteristics, such as broadband content, are held constant. The system can also generate simulations of the predicted noise characteristics of future aircraft. A description of the synthesis system and a discussion of the algorithms and methods used to generate the simulations are provided. An appendix describing the input data and providing user instructions is also included.

Mccurdy, David A.; Grandle, Robert E.

1987-01-01

388

Aircraft control position indicator  

NASA Technical Reports Server (NTRS)

An aircraft control position indicator was provided that displayed the degree of deflection of the primary flight control surfaces and the manner in which the aircraft responded. The display included a vertical elevator dot/bar graph meter display for indication whether the aircraft will pitch up or down, a horizontal aileron dot/bar graph meter display for indicating whether the aircraft will roll to the left or to the right, and a horizontal dot/bar graph meter display for indicating whether the aircraft will turn left or right. The vertical and horizontal display or displays intersect to form an up/down, left/right type display. Internal electronic display driver means received signals from transducers measuring the control surface deflections and determined the position of the meter indicators on each dot/bar graph meter display. The device allows readability at a glance, easy visual perception in sunlight or shade, near-zero lag in displaying flight control position, and is not affected by gravitational or centrifugal forces.

Dennis, Dale V. (inventor)

1987-01-01

389

Identification of Aircraft Hazards  

SciTech Connect

Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7).

K. Ashley

2006-12-08

390

IDENTIFICATION OF AIRCRAFT HAZARDS  

SciTech Connect

Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7).

K.L. Ashley

2005-03-23

391

Inviscid modeling of aircraft trailing vortices  

NASA Technical Reports Server (NTRS)

A survey is presented of inviscid theoretical methods that are useful in the study of lift-generated vortices. Concepts derived using these invisicid theories are cited which have helped to guide research directed at alleviating the velocities and rolling moments imposed on aircraft entering these wakes.

Rossow, V. J.

1977-01-01

392

Flying qualities criteria for superaugmented aircraft  

NASA Technical Reports Server (NTRS)

An overview of Dryden superaugmented aircraft flying qualities research is presented. This includes F-8 digital fly by wire flight experiments, orbiter flying qualities, shuttle improvements, AFTI/F-16, flying qualities and control system alternatives, Vertical Motion Simulator Shuttle evaluation and Total in Flight Simulator pitch rate criteria.

Berry, D. T.

1984-01-01

393

Instrumentation for Unmanned Aircraft Systems (UAS)  

E-print Network

Instrumentation for Unmanned Aircraft Systems (UAS) David Delene Department of Atmospheric Sciences on at the University of North Dakota. · What are the prospects for UAS measurements? Right Wing of Citation Research Spectrometer Are some Instrument just to complex for UAS operations? #12;Airborne Aerosol Mass Spectrometer

Delene, David J.

394

Simulation Packages Expand Aircraft Design Options  

NASA Technical Reports Server (NTRS)

In 2001, NASA released a new approach to computational fluid dynamics that allows users to perform automated analysis on complex vehicle designs. In 2010, Palo Alto, California-based Desktop Aeronautics acquired a license from Ames Research Center to sell the technology. Today, the product assists organizations in the design of subsonic aircraft, space planes, spacecraft, and high speed commercial jets.

2013-01-01

395

Neural networks for aircraft system identification  

NASA Technical Reports Server (NTRS)

Artificial neural networks offer some interesting possibilities for use in control. Our current research is on the use of neural networks on an aircraft model. The model can then be used in a nonlinear control scheme. The effectiveness of network training is demonstrated.

Linse, Dennis J.

1991-01-01

396

Simulation model for aircraft line maintenance planning  

Microsoft Academic Search

This paper reports results of research that developed a computerized simulation model for the aircraft line maintenance department in Continental Airlines. The original AUTOMOD model that was created duplicated the maintenance operations at Continental's major maintenance station at Newark. Modeling the day-to-day maintenance activities lead to the development of enhanced staffing models and a better understanding of resource requirements on

P. Gupta; M. Bazargan; R. N. McGrath

2003-01-01

397

Aircraft Safety and Operating Problems. [conference  

NASA Technical Reports Server (NTRS)

Results of NASA research in the field of aircraft safety and operating problems are discussed. Topics include: (1) terminal area operations, (2) flight dynamics and control; (3) ground operations; (4) atmospheric environment; (5) structures and materials; (6) powerplants; (7) noise; and (8) human factors engineering.

1976-01-01

398

Comparison of onboard aircraft Nicad battery chargers  

Microsoft Academic Search

A test was conducted at the Applied Technology Laboratory at Fort Eustis, Virginia to establish the performance characteristics of several onboard aircraft NiCad battery chargers. The test assessed performance characteristics of chargers from Utah Research and Development Company, Aerospace Avionics Corp., Eldec Corp., and Chrysler Corp. These performance characteristics were also compared to the battery performance associated with a simulated

J. D. Dickinson

1980-01-01

399

An aircraft manufacturer's approach to rideability criteria  

NASA Technical Reports Server (NTRS)

The approach of an aircraft manufacturer to ride quality in air transportation is presented. The subjects discussed are: (1) the external and internal environment in terms of vibration and acoustic sources and general response, (2) guidelines and criteria reflecting current practice, (3) present and future efforts to develop rideability criteria, and (4) requirements for data, criteria, and research in various rideability areas.

Omassey, R. C.; Leve, H.; Gaume, J. G.

1972-01-01

400

Predicted aircraft effects on stratospheric ozone  

NASA Technical Reports Server (NTRS)

The possibility that the current fleet of subsonic aircraft may already have caused detectable changes in both the troposphere and stratosphere has raised concerns about the impact of such operations on stratospheric ozone and climate. Recent interest in the operation of supersonic aircraft in the lower stratosphere has heightened such concerns. Previous assessments of impacts from proposed supersonic aircraft were based mostly on one-dimensional model results although a limited number of multidimensional models were used. In the past 15 years, our understanding of the processes that control the atmospheric concentrations of trace gases has changed dramatically. This better understanding was achieved through accumulation of kinetic data and field observations as well as development of new models. It would be beneficial to start examining the impact of subsonic aircraft to identify opportunities to study and validate the mechanisms that were proposed to explain the ozone responses. The two major concerns are the potential for a decrease in the column abundance of ozone leading to an increase in ultraviolet radiation at the ground, and redistribution of ozone in the lower stratosphere and upper troposphere leading to changes in the Earth's climate. Two-dimensional models were used extensively for ozone assessment studies, with a focus on responses to chlorine perturbations. There are problems specific to the aircraft issues that are not adequately addressed by the current models. This chapter reviews the current status of the research on aircraft impact on ozone with emphasis on immediate model improvements necessary for extending our understanding. The discussion will be limited to current and projected commercial aircraft that are equipped with air-breathing engines using conventional jet fuel. The impacts are discussed in terms of the anticipated fuel use at cruise altitude.

Ko, Malcolm K. W.; Wofsy, Steve; Kley, Dieter; Zhadin, Evgeny A.; Johnson, Colin; Weisenstein, Debra; Prather, Michael J.; Wuebbles, Donald J.

1991-01-01

401

Damage tolerance for commuter aircraft  

NASA Technical Reports Server (NTRS)

The damage tolerance experience in the United States Air Force with military aircraft and in the commercial world with large transport category aircraft indicates that a similar success could be achieved in commuter aircraft. The damage tolerance process is described for the purpose of defining the approach that could be used for these aircraft to ensure structural integrity. Results of some of the damage tolerance assessments for this class of aircraft are examined to illustrate the benefits derived from this approach. Recommendations are given for future damage tolerance assessment of existing commuter aircraft and on the incorporation of damage tolerance capability in new designs.

Lincoln, John W.

1992-01-01

402

A strategic planning methodology for aircraft redesign  

NASA Astrophysics Data System (ADS)

Due to a progressive market shift to a customer-driven environment, the influence of engineering changes on the product's market success is becoming more prominent. This situation affects many long lead-time product industries including aircraft manufacturing. Derivative development has been the key strategy for many aircraft manufacturers to survive the competitive market and this trend is expected to continue in the future. Within this environment of design adaptation and variation, the main market advantages are often gained by the fastest aircraft manufacturers to develop and produce their range of market offerings without any costly mistakes. This realization creates an emphasis on the efficiency of the redesign process, particularly on the handling of engineering changes. However, most activities involved in the redesign process are supported either inefficiently or not at all by the current design methods and tools, primarily because they have been mostly developed to improve original product development. In view of this, the main goal of this research is to propose an aircraft redesign methodology that will act as a decision-making aid for aircraft designers in the change implementation planning of derivative developments. The proposed method, known as Strategic Planning of Engineering Changes (SPEC), combines the key elements of the product redesign planning and change management processes. Its application is aimed at reducing the redesign risks of derivative aircraft development, improving the detection of possible change effects propagation, increasing the efficiency of the change implementation planning and also reducing the costs and the time delays due to the redesign process. To address these challenges, four research areas have been identified: baseline assessment, change propagation prediction, change impact analysis and change implementation planning. Based on the established requirements for the redesign planning process, several methods and tools that are identified within these research areas have been abstracted and adapted into the proposed SPEC method to meet the research goals. The proposed SPEC method is shown to be promising in improving the overall efficiency of the derivative aircraft planning process through two notional aircraft system redesign case studies that are presented in this study.

Romli, Fairuz Izzuddin

403

Aerodynamic design trends for commercial aircraft  

NASA Technical Reports Server (NTRS)

Recent research on advanced-configuration commercial aircraft at DFVLR is surveyed, with a focus on aerodynamic approaches to improved performance. Topics examined include transonic wings with variable camber or shock/boundary-layer control, wings with reduced friction drag or laminarized flow, prop-fan propulsion, and unusual configurations or wing profiles. Drawings, diagrams, and graphs of predicted performance are provided, and the need for extensive development efforts using powerful computer facilities, high-speed and low-speed wind tunnels, and flight tests of models (mounted on specially designed carrier aircraft) is indicated.

Hilbig, R.; Koerner, H.

1986-01-01

404

PIK-20 Aircraft in Flight  

NASA Technical Reports Server (NTRS)

This photo shows NASA's PIK-20E motor-glider sailplane during a research flight from the Ames-Dryden Flight Research Facility (later, the Dryden Flight Research Center), Edwards, California, in 1991. The PIK-20E was a sailplane flown at NASA's Ames-Dryden Flight Research Facility (now Dryden Flight Research Center, Edwards, California) beginning in 1981. The vehicle, bearing NASA tail number 803, was used as a research vehicle on projects calling for high lift-over-drag and low-speed performance. Later NASA used the PIK-20E to study the flow of fluids over the aircraft's surface at various speeds and angles of attack as part of a study of airflow efficiency over lifting surfaces. The single-seat aircraft was used to begin developing procedures for collecting sailplane glide performance data in a program carried out by Ames-Dryden. It was also used to study high-lift aerodynamics and laminar flow on high-lift airfoils. Built by Eiri-Avion in Finland, the PIK-20E is a sailplane with a two-cylinder 43-horsepower, retractable engine. It is made of carbon fiber with sandwich construction. In this unique configuration, it takes off and climbs to altitude on its own. After reaching the desired altitude, the engine is shut down and folded back into the fuselage and the aircraft is then operated as a conventional sailplane. Construction of the PIK-20E series was rather unusual. The factory used high-temperature epoxies cured in an autoclave, making the structure resistant to deformation with age. Unlike today's normal practice of laying glass over gelcoat in a mold, the PIK-20E was built without gelcoat. The finish is the result of smooth glass lay-up, a small amount of filler, and an acrylic enamel paint. The sailplane was 21.4 feet long and had a wingspan of 49.2 feet. It featured a wooden, fixed-pitch propeller, a roomy cockpit, wingtip wheels, and a steerable tailwheel.

1991-01-01

405

Altus I aircraft on lakebed  

NASA Technical Reports Server (NTRS)

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 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.

1997-01-01

406

Propulsion controlled aircraft: A nonlinear perspective  

SciTech Connect

Research and flight testing have been done on the feasibility and implementation of the concept of using only engine thrust as emergency backup flight control for aircraft, known as the propulsion controlled aircraft (PCA). This paper reviews some notable nonlinear phenomena observed in the PCA flight tests. Flight test data for an F-18 aircraft is presented to illustrate these aspects. It is suggested that an appropriately designed nonlinear controller for the PCA will likely respond better to these nonlinearities and hence provide more effective control in such a very stringent situation. A recent nonlinear continuous predictive control method is introduced as a potentially suitable technique for this purpose. A flight control problem is then presented to demonstrate the effectiveness of this method while some other linear and nonlinear approaches are not applicable.

Lu, Ping [Iowa State Univ., Ames, IA (United States); Burken, J.J. [NASA Dryden Flight Research Center, Edwards, CA (United States)

1994-12-31

407

Aircraft surface coatings  

NASA Technical Reports Server (NTRS)

Liquid, spray on elastomeric polyurethanes are selected and investigated as best candidates for aircraft external protective coatings. Flight tests are conducted to measure drag effects of these coatings compared to paints and a bare metal surface. The durability of two elastometric polyurethanes are assessed in airline flight service evaluations. Laboratory tests are performed to determine corrosion protection properties, compatibility with aircraft thermal anti-icing systems, the effect of coating thickness on erosion durability, and the erosion characteristics of composite leading edges-bare and coated. A cost and benefits assessment is made to determine the economic value of various coating configurations to the airlines.

1982-01-01

408

Aircraft Laminar Flow Control  

NASA Technical Reports Server (NTRS)

Aircraft laminar flow control (LFC) from the 1930's through the 1990's is reviewed and the current status of the technology is assessed. Examples are provided to demonstrate the benefits of LFC for subsonic and supersonic aircraft. Early studies related to the laminar boundary-layer flow physics, manufacturing tolerances for laminar flow, and insect-contamination avoidance are discussed. LFC concept studies in wind-tunnel and flight experiments are the major focus of the paper. LFC design tools are briefly outlined for completeness.

Joslin, Ronald D.

1998-01-01

409

Alternative aircraft fuels  

NASA Technical Reports Server (NTRS)

The efficient utilization of fossil fuels by future jet aircraft may necessitate the broadening of current aviation turbine fuel specifications. The most significant changes in specifications would be an increased aromatics content and a higher final boiling point in order to minimize refinery energy consumption and costs. These changes would increase the freezing point and might lower the thermal stability of the fuel, and could cause increased pollutan