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  1. DEVELOPMENT AND FLIGHT TEST EXPERIENCES WITH A FLIGHT-CRUCIAL DIGITAL CONTROL SYSTEM
    Authors: Dale A. Mackall
    Report Number: NASA-TP-2857
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Engineers and scientists in the advanced fighter technology integration (AFTI) F-16 program investigated the integration of emerging technologies into an advanced fighter aircraft. AFTI's three major technologies included: flight-crucial digital control, decoupled aircraft flight control, and integration of avionics, flight control, and pilot displays. In addition to investigating improvements in fighter performance, researchers studied the generic problems confronting the designers of highly integrated flight-crucial digital control. An overview is provided of both the advantages and problems of integration digital control systems. Also, an examination of the specification, design, qualification, and flight test life-cycle phase is provided. An overview is given of the fault-tolerant design, multimoded decoupled flight control laws, and integrated avionics design. The approach to qualifying the software and system designs is discussed, and the effects of design choices on system qualification are highlighted.
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    Subject Category: 08
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    Report Date: November 1988
    No. Pages: 116
    Keywords:      Aircraft performance; Control systems design; Digital systems; F-16 aircraft; Flight control.


  2. ANALYSIS PROCEDURES AND SUBJECTIVE FLIGHT RESULTS OF A SIMULATOR VALIDATIONAND CUE FIDELITY EXPERIMENT
    Authors: Peter C. Carr and Burnell T. McKissick
    Report Number: NASA-TM-88270
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A joint experiment to investigate simulator validation and cue fidelity was conducted by the Dryden Flight Research Facility of NASA Ames Research Center (Ames-Dryden) and NASA Langley Research Center. The primary objective was to validate the use of a closed-loop pilot-vehicle mathematical model as an analytical tool for optimizing the tradeoff between simulator fidelity requirements and simulator cost. The validation process includes comparing model predictions with simulation and flight test results to evaluate various hypotheses for differences in motion and visual cues and information transfer. A group of five pilots flew air-to-air tracking maneuvers in the Langley differential maneuvering simulator and visual motion simulator and in an F-14 aircraft at Ames-Dryden. The simulators used motion and visual cueing devices including a g-seat, a helmet loader, wide field-of-view horizon, and a motion base platform.
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    Report Date: July 1988
    No. Pages: 31
    Keywords:      Cues; Flight simulators; Flight tests; Pilot performance; Proving.


  3. DERIVATION AND DEFINITION OF A LINEAR AIRCRAFT MODEL
    Authors: Eugene L. Duke, Robert F. Antoniewicz and Keith D. Krambeer
    Report Number: NASA-RP-1207
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A linear aircraft model for a rigid aircraft of constant mass flying over a flat, nonrotating earth is derived and defined. The derivation makes no assumptions of reference trajectory or vehicle symmetry. The linear system equations are derived and evaluated along a general trajectory and include both aircraft dynamics and observation variables.
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    Report Date: August 1988
    No. Pages: 106
    Keywords:      Aircraft models; Dynamic models; Equations of state; Flight mechanics; Linear systems.


  4. INFLUENCE OF BASE MODIFICATIONS ON IN-FLIGHT BASE DRAG IN THE PRESENCE OF JET EXHAUST FOR MACH NUMBERS FROM 0.7 TO 1.5
    Authors: Sheryll Goecke Powers
    Report Number: NASA-TP-2802
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The use of external modifications in the base region to reduce the base drag of a blunt-base body in the presence of jet engine exhaust was investigated in flight. Base pressure data were obtained for the following configurations: (1) blunt base; (2) blunt base modified with splitter plate; and (3) blunt base modified with two variations of a vented cavity. Reynolds number based on the length of the aircraft ranged from 1.2 to 3.1 x 10 to the 8th. Mach number M ranges were 0.71 less than or = M less than or = 0.95 and 1.10 less than or = M less than or = 1.51. The data were analyzed using the blunt base for a reference, or baseline condition. For 1.10 less than or = M less than or = 1.51, the reduction in base drag coefficient provided by the vented cavity configuration ranged from 0.07 to 0.05. These increments in base drag coefficient at M = 1.31 and 1.51 result in base drag reductions of 27 and 24 percent, respectively, when compared to the blunt base drag. For M less than 1, the drag increment between the blunt base and the modification is not significant.
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    Subject Category: 34
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    Report Date: February 1988
    No. Pages: 20
    Keywords:      Base flow; Drag; Flight tests; Jet exhaust; Mach number.


  5. USER'S MANUAL FOR EZPLOT VERSION 5.5: A FORTRAN PROGRAM FOR2-DIMENSIONAL GRAPHIC DISPLAY OF DATA
    Authors: Charles Garbinski, Paul C. Redin and Gerald D. Budd
    Report Number: NASA-TM-88293
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: EZPLOT is a computer applications program that converts data resident on a file into a plot displayed on the screen of a graphics terminal. This program generates either time history or x-y plots in response to commands entered interactively from a terminal keyboard. Plot parameters consist of a single independent parameter and from one to eight dependent parameters. Various line patterns, symbol shapes, axis scales, text labels, and data modification techniques are available. This user's manual describes EZPLOT as it is implemented on the Ames Research Center, Dryden Research Facility ELXSI computer using DI-3000 graphics software tools.
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    Subject Category: 61
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    Report Date: October 1988
    No. Pages: 45
    Keywords:      Computer graphics; Display devices; FORTRAN; Two dimensional models; Users manual (computer programs).


  6. GROUND VORTEX FLOW FIELD INVESTIGATION
    Authors: Richard E. Kuhn, John H. Del Frate and James E. Eshleman
    Report Number: NASA-CP-10008
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Flow field investigations were conducted at the NASA Ames-Dryden Flow Visualization Facility (water tunnel) to investigate the ground effect produced by the impingement of jets from aircraft nozzles on a ground board in a STOL operation. Effects on the overall flow field with both a stationary and a moving ground board were photographed and compared with similar data found in other references. Nozzle jet impingement angles, nozzle and inlet interaction, side-by-side nozzles, nozzles in tandem, and nozzles and inlets mounted on a flat plate model were investigated. Results show that the wall jet that generates the ground effect is unsteady and the boundary between the ground vortex flow field and the free-stream flow is unsteady. Additionally, the forward projection of the ground vortex flow field with a moving ground board is one-third less than that measured over a fixed ground board. Results also showed that inlets did not alter the ground vortex flow field.
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    Subject Category: 02
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    Report Date: February 1988
    No. Pages: 30
    Keywords:      Flow distribution; Flow visualization; Ground effect (aerodynamics); Jet exhaust; Short takeoff aircraft.
    Notes: In its The 1987 Ground Vortex Workshop p 61-90.


  7. DELAMINATION STRESSES IN SEMICIRCULAR LAMINATED COMPOSITE BARS
    Authors: William L. Ko
    Report Number: NASA-TM-4026
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Using anisotropic elasticity theory, delamination stresses in a semicircular laminated composite curved bar subjected to end forces and end moments were calculated, and their radial locations determined. A family of design curves was presented, showing variation of the intensity of delamination stresses and their radial locations with different geometry and different degrees of anisotropy of the curved bar. The effect of anisotropy on the location of peak delamination stress was found to be small.
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    Subject Category: 24
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    Report Date: January 1988
    No. Pages: 27
    Keywords:      Bars; Composite materials; Curved beams; Delaminating; Laminates.


  8. CONCEPT OF A PROGRAMMABLE MAINTENANCE PROCESSOR APPLICABLE TO MULTIPROCESSING SYSTEMS
    Authors: Richard D. Glover
    Report Number: NASA-TM-100406
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A programmable maintenance processor concept applicable to multiprocessing systems has been developed at the NASA Ames Research Center's Dryden Flight Research Facility. This stand-alone-processor is intended to provide support for system and application software testing as well as hardware diagnostics. An initial machanization has been incorporated into the extended aircraft interrogation and display system (XAIDS) which is multiprocessing general-purpose ground support equipment. The XAIDS maintenance processor has independent terminal and printer interfaces and a dedicated magnetic bubble memory that stores system test sequences entered from the terminal. This report describes the hardware and software embodied in this processor and shows a typical application in the check-out of a new XAIDS.
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    Subject Category: 74
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    Report Date: February 1988
    No. Pages: 74
    Keywords:      Applications programs (computers); Computer programming; Maintenance; Multiprocessing (computers).


  9. FLIGHT CONTROL SYSTEMS DEVELOPMENT AND FLIGHT TEST EXPERIENCE WITH THEHIMAT RESEARCH VEHICLES
    Authors: Robert W. Kempel and Michael R. Earls
    Report Number: NASA-TP-2822
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Two highly maneuverable aircraft technology (HiMAT) remotely piloted vehicles were flown a total of 26 flights. These subscale vehicles were of advanced aerodynamic configuration with advanced technology concepts such as composite and metallic structures, digital integrated propulsion control, and ground (primary) and airborne (backup) relaxed static stability, digital fly-by-wire control systems. Extensive systems development, checkout, and flight qualification were required to conduct the flight test program. The design maneuver goal was to achieve a sustained 8-g turn at Mach 0.9 at an altitude of 25,000 feet. This goal was achieved, along with the acquisition of high-quality flight data at subsonic and supersonic Mach numbers. Control systems were modified in a variety of ways using the flight-determined aerodynamic characteristics. The HiMAT program was successfully completed with approximately 11 hours of total flight time.
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    Subject Category: 08
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    Report Date: June 1988
    No. Pages: 88
    Keywords:      Digital systems; Flight control; Flight tests; Highly maneuverable aircraft; Remotely piloted vehicles.


  10. A PILOTED EVALUATION OF AN OBLIQUE-WING RESEARCH AIRCRAFT MOTION SIMULATION WITH DECOUPLING CONTROL LAWS
    Authors: Robert W. Kempel, Walter E. McNeill, Glenn B. Gilyard and Trindel A. Maine
    Report Number: NASA-TP-2874
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: 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.
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    Report Date: November 1988
    No. Pages: 52
    Keywords:      Decoupling; Evaluation; Flight simulation; Flight tests; Oblique wings.


  11. PRELIMINARY IN-FLIGHT BOUNDARY LAYER TRANSITION MEASUREMENTS ON A 45 DEGSWEPT WING AT MACH NUMBERS BETWEEN 0.9 AND 1.8
    Authors: J. Blair Johnson
    Report Number: NASA-TM-100412
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A preliminary flight experiment was flown to generate a full-scale supersonic data base to aid the assessment of computational codes, to improve instrumentation for measuring boundary layer transition at supersonic speeds, and to provide preliminary information for the definition of follow-on programs. The experiment was conducted using an F-15 aircraft modified with a small cleanup test section on the right wing. Results are presented for Mach (M) numbers from 0.9 to 1.8 at altitudes from 25,000 to 55,000 ft. At M greater than or = 1.2, transition occurred near or at the leading edge for the clean configuration. The furthest aft that transition was measured was 20 percent chord at M = 0.9 and M = 0.97. No change in transition location was observed after the addition of a notch-bump on the leading edge of the inboard side of the test section which was intended to minimize attachment line transition problems. Some flow visualization was attempted during the flight experiment with both subliming chemicals and liquid crystals. However, difficulties arose from the limited time the test aircraft was able to hold test conditions and the difficulty of positioning the photo chase aircraft during supersonic test points. Therefore, no supersonic transition results were obtained.
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    Subject Category: 34
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    Report Date: March 1988
    No. Pages: 47
    Keywords:      Boundary layer transition; F-15 aircraft; Flight tests; Mach number; Swept wings.


  12. EFFECTS OF UPDATE AND REFRESH RATES ON FLIGHT SIMULATION VISUAL DISPLAYS
    Authors: Gary V. Kellogg and Charles A. Wagner
    Report Number: NASA-TM-100415
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An experiment was performed to study the effects of update and refresh rates on dynamic calligraphic CRT displays, particularly those used for visual displays in flight simulators. A moving horizontal line was generated on a CRT and observed at various velocities. Observations were made with both one and two refreshes per update. The data gathered from these observations are presented on plots of refresh-update rate as a function of display velocity. The display velocity where picture degradation occurs can be found by using these plots. These velocities are related to actual simulated aircraft angular and linear velocities. Results show that a visual display updated at 30 Hz and refreshed at 60 Hz degrades at very low simulated aircraft angular and linear velocities. These velocities at which degradation occurs can be significantly increased by increasing the update rate of the visual display. Only minor improvements are possible by refreshing the display twice for each uptake. To display rapidly changing flight scenery without degradation, the display update rate must be far in excess of 60 Hz, typically several hundred Hz.
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    Subject Category: 05
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    Report Date: May 1988
    No. Pages: 19
    Keywords:      Computer graphics; Display devices; Flight simulation; Imaging techniques; Motion simulation.


  13. A COMPARISON OF EXPERIMENTAL AND CALCULATED THIN-SHELL LEADING-EDGE BUCKLING DUE TO THERMAL STRESSES
    Authors: Jerald M. Jenkins
    Report Number: NASA-TM-100416
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: High-temperature thin-shell leading-edge buckling test data are analyzed using NASA structural analysis (NASTRAN) as a finite element tool for predicting thermal buckling characteristics. Buckling points are predicted for several combinations of edge boundary conditions. The problem of relating the appropriate plate area to the edge stress distribution and the stress gradient is addressed in terms of analysis assumptions. Local plasticity was found to occur on the specimen analyzed, and this tended to simplify the basic problem since it effectively equalized the stress gradient from loaded edge to loaded edge. The initial loading was found to be difficult to select for the buckling analysis because of the transient nature of thermal stress. Multiple initial model loadings are likely required for complicated thermal stress time histories before a pertinent finite element buckling analysis can be achieved. The basic mode shapes determined from experimentation were correctly identified from computation.
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    Subject Category: 39
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    Report Date: July 1988
    No. Pages: 17
    Keywords:      Leading edges; NASTRAN; Thermal buckling; Thermal stresses; Thin walled shells.


  14. OBLIQUE-WING RESEARCH AIRPLANE MOTION SIMULATION WITH DECOUPLING CONTROLLAWS
    Authors: Robert W. Kempel, Walter E. McNeill and Trindel A. Maine
    Report Number: H-1441
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A large piloted vertical motion simulator was used to assess the performance of a preliminary decoupling control law for an early version of the F-8 oblique wing research demonstrator airplane. Evaluations were performed for five discrete flight conditions, ranging from low-altitude subsonic Mach numbers to moderate-altitude supersonic Mach numbers. Asymmetric sideforce as a function of angle of attack was found to be the primary cause of both the lateral acceleration noted in pitch and the tendency to roll into left turns and out of right turns. The flight control system was shown to be effective in generally decoupling the airplane and reducing the lateral acceleration in pitch maneuvers.
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    Subject Category: 08
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    Report Date: January 1988
    No. Pages: 21
    Keywords:      Control configured vehicles; Fly by wire control; Motion simulation; Oblique wings; Research aircraft.
    Notes: AIAA, Aerospace Sciences Meeting, 26th, Reno, NV, Jan. 11-14, 1988. 21 p.


  15. SOLUTION ACCURACIES OF FINITE ELEMENT REENTRY HEAT TRANSFER AND THERMAL STRESSANALYSES OF SPACE SHUTTLE ORBITER
    Authors: William L. Ko
    Report Number: H-1442
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Accuracies of solutions (structural temperatures and thermal stresses) obtained from different thermal and structural FEMs set up for the Space Shuttle Orbiter (SSO) are compared and discussed. For studying the effect of element size on the solution accuracies of heat-transfer and thermal-stress analyses of the SSO, five SPAR thermal models and five NASTRAN structural models were set up for wing midspan bay 3. The structural temperature distribution over the wing skin (lower and upper) surface of one bay was dome shaped and induced more severe thermal stresses in the chordwise direction than in the spanwise direction. The induced thermal stresses were extremely sensitive to slight variation in structural temperature distributions. Both internal convention and internal radiation were found to have equal effects on the SSO.
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    Subject Category: 18
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    Report Date: June 1988
    No. Pages: 27
    Keywords:      Finite element method; Heat transfer; Space shuttle orbiters; Spacecraft reentry; Thermal analysis.
    Notes: International Journal for Numerical Methods in Engineering (ISSN 0029-5981), vol. 25, June 1988, p. 517-543.


  16. USER'S MANUAL FOR INTERACTIVE LINEAR: A FORTRAN PROGRAM TO DERIVE LINEAR AIRCRAFT MODELS
    Authors: Robert F. Antoniewicz, Eugene L. Duke and Brian P. Patterson
    Report Number: NASA-TP-2835
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An interactive FORTRAN program that provides the user with a powerful and flexible tool for the linearization of aircraft aerodynamic models is documented in this report. The program LINEAR numerically determines a linear system model using nonlinear equations of motion and a user-supplied linear or nonlinear aerodynamic model. The nonlinear equations of motion used are six-degree-of-freedom equations with stationary atmosphere and flat, nonrotating earth assumptions. The system model determined by LINEAR consists of matrices for both the state and observation equations. The program has been designed to allow easy selection and definition of the state, control, and observation variables to be used in a particular model.
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    Subject Category: 66
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    Report Date: September 1988
    No. Pages: 126
    Keywords:      Aircraft design; FORTRAN; Interactive control; Linear systems; Users Manuals (computer programs).


  17. AIRCRAFT FLIGHT FLUTTER TESTING AT THE NASA AMES-DRYDEN FLIGHT RESEARCHFACILITY
    Authors: Michael W. Kehoe
    Report Number: NASA-TM-100417
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Many parameter identification techniques have been used at the NASA Ames Research Center, Dryden Research Facility at Edwards Air Force Base to determine the aeroelastic stability of new and modified research vehicles in flight. This paper presents a summary of each technique used with emphasis on fast Fourier transform methods. Experiences gained from application of these techniques to various flight test programs are discussed. Also presented are data-smoothing techniques used for test data distorted by noise. Data are presented for various aircraft to demonstrate the accuracy of each parameter identification technique discussed.
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    Subject Category: 05
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    Report Date: May 1988
    No. Pages: 17
    Keywords:      Flight tests; Flutter analysis; Parameter identification; Research facilities; Test facilities.
    Notes: Presented at the AIAA 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  18. THE NASA INTEGRATED TEST FACILITY AND ITS IMPACT ON FLIGHT RESEARCH
    Authors: D. A. Mackall, M. D. Pickett, L. J. Schilling and C. A. Wagner
    Report Number: NASA-TM-100418
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The Integrated Test Facility (ITF), being built at NASA Ames-Dryden Flight Research Facility, will provide new test capabilities for emerging research aircraft. An overview of the ITF and the challenges being addressed by this unique facility are outlined. The current ITF capabilities, being developed with the X-29 Forward Swept Wing Program, are discussed along with future ITF activities.
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    Subject Category: 09
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    Report Date: May 1988
    No. Pages: 16
    Keywords:      Aircraft design; Flight tests; Ground tests; Research aircraft; Research facilities.
    Notes: Presented at the 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  19. FLIGHT TEST EXPERIENCE AND CONTROLLED IMPACT OF A REMOTELY PILOTED JETTRANSPORT AIRCRAFT
    Authors: Timothy W. Horton and Robert W. Kempel
    Report Number: NASA-TM-4084
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The Dryden Flight Research Center Facility of NASA Ames Research Center (Ames-Dryden) and the FAA conducted the controlled impact demonstration (CID) program using a large, four-engine, remotely piloted jet transport airplane. Closed-loop primary flight was controlled through the existing onboard PB-20D autopilot which had been modified for the CID program. Uplink commands were sent from a ground-based cockpit and digital computer in conjunction with an up-down telemetry link. These uplink commands were received aboard the airplane and transferred through uplink interface systems to the modified PB-20D autopilot. Both proportional and discrete commands were produced by the ground system. Prior to flight tests, extensive simulation was conducted during the development of ground-based digital control laws. The control laws included primary control, secondary control, and racetrack and final approach guidance. Extensive ground checks were performed on all remotely piloted systems; however, piloted flight tests were the primary method and validation of control law concepts developed from simulation. The design, development, and flight testing of control laws and systems required to accomplish the remotely piloted mission are discussed.
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    Subject Category: 05
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    Report Date: November 1988
    No. Pages: 44
    Keywords:      Flight tests; Impact tests; Jet aircraft; Remote control; Transport aircraft.


  20. AEROSPACE ENERGY SYSTEMS LABORATORY: REQUIREMENTS AND DESIGN APPROACH
    Authors: Richard D. Glover
    Report Number: NASA-TM-100423
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The NASA Ames-Dryden Flight Research Facility at Edwards, California, operates a mixed fleet of research aircraft employing nickel-cadmium (NiCd) batteries in a variety of flight-critical applications. Dryden's Battery Systems Laboratory (BSL), a computerized facility for battery maintenance servicing, has developed over two decades into one of the most advanced facilities of its kind in the world. Recently a major BSL upgrade was initiated with the goal of modernization to provide flexibility in meeting the needs of future advanced projects. The new facility will be called the Aerospace Energy Systems Laboratory (AESL) and will employ distributed processing linked to a centralized data base. AESL will be both a multistation servicing facility and a research laboratory for the advancement of energy storage system maintenance techniques. This paper describes the baseline requirements for the AESL and the design approach being taken for its mechanization.
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    Subject Category: 62
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    Report Date: May 1988
    No. Pages: 12
    Keywords:      Aircraft power supplies; Energy storage; Maintenance; Nickel cadmium batteries; Research facilities.
    Notes: Presented at the ISA Aerospace Industries/Test Measurement Symposium, Albuquerque, N. Mex., 2-5 May 1988.


  21. FLIGHT MEASURED AND CALCULATED EXHAUST JET CONDITIONS FOR AN F100 ENGINE INAN F-15 AIRPLANE
    Authors: Francisco J. Hernandez and Frank W. Burcham, Jr.
    Report Number: NASA-TM-100419
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The exhaust jet conditions, in terms of temperature and Mach number, were determined for a nozzle-aft end acoustic study flown on an F-15 aircraft. Jet properties for the F100 EMD engines were calculated using the engine manufacturer's specification deck. The effects of atmospheric temperature on jet Mach number, M10, were calculated. Values of turbine discharge pressure, PT6M, jet Mach number, and jet temperature were calculated as a function of aircraft Mach number, altitude, and power lever angle for the test day conditions. At a typical test point with a Mach number of 0.9, intermediate power setting, and an altitude of 20,000 ft, M10 was equal to 1.63. Flight measured and calculated values of PT6M were compared for intermediate power at altitudes of 15500, 20500, and 31000 ft. It was found that at 31000 ft, there was excellent agreement between both, but for lower altitudes the specification deck overpredicted the flight data. The calculated jet Mach numbers were believed to be accurate to within 2 percent.
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    Subject Category: 07
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    Report Date: October 1988
    No. Pages: 17
    Keywords:      Engine design; F-15 aircraft; Jet flow; Mach number; Nozzle design.


  22. THE DESIGN AND USE OF A TEMPERATURE-COMPENSATED HOT-FILM ANEMOMETER SYSTEM FOR BOUNDARY-LAYER FLOW TRANSITION DETECTION ON SUPERSONIC AIRCRAFT
    Authors: Harry R. Chiles
    Report Number: NASA-TM-100421
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An airborne temperature-compensated hot-film anemometer system has been designed, fabricated, and used to obtain in-flight airfoil boundary-layer flow transition data by the NASA Ames-Dryden Flight Research Facility. Salient features of the anemometer include near constant sensitivity over the full flight envelope, installation without coaxial wiring, low-noise outputs, and self-contained signal conditioning with dynamic and steady-state outputs. The small size, low-power dissipation, and modular design make the anemometer suitable for use in modern high-performance research aircraft. Design of the temperature-compensated hot-film anemometer and its use for flow transition detection on a laminar flow flight research project are described. Also presented are data gathered in flight which is representative of the temperature-compensated hot-film anemometer operation at subsonic, transonic, and supersonic flight conditions.
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    Subject Category: 06
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    Report Date: May 1988
    No. Pages: 14
    Keywords:      Boundary layer flow; Design analysis; Flight tests; Hot-film anemometers; Supersonic aircraft.
    Notes: Presented at the Aerospace Industries/Test Measurement Symposium, Albuquerque, N. Mex., 2-5 May 1988.


  23. EFFECTS OF MANEUVER DYNAMICS ON DRAG POLARS OF THE X-29AFORWARD-SWEPT-WING AIRCRAFT WITH AUTOMATIC WING CAMBER CONTROL
    Authors: John W. Hicks and Bryan J. Moulton
    Report Number: H-1452
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The camber control loop of the X-29A FSW aircraft was designed to furnish the optimum L/D for trimmed, stabilized flight. A marked difference was noted between automatic wing camber control loop behavior in dynamic maneuvers and in stabilized flight conditions, which in turn affected subsonic aerodynamic performance. The degree of drag level increase was a direct function of maneuver rate. Attention is given to the aircraft flight drag polar effects of maneuver dynamics in light of wing camber control loop schedule. The effect of changing camber scheduling to better track the optimum automatic camber control L/D schedule is discussed.
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    Report Date: January 1988
    No. Pages: 11
    Keywords:      Aircraft maneuvers; Automatic control; Lift drag ratio; Swept forward wings; Wing camber.
    Notes: IN: AIAA Flight Test Conference, 4th, San Diego, CA, May 18-20, 1988, Technical Papers. AIAA 88-2144. Washington, DC, American Institute of Aeronautics and Astronautics, 1988, p. 312-322.


  24. REAL-TIME FLIGHT TEST DATA DISTRIBUTION AND DISPLAY
    Authors: Michael C. Nesel and Kevin R. Hammons
    Report Number: NASA-TM-100424
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Enhancements to the real-time processing and display systems of the NASA Western Aeronautical Test Range are described. Display processing has been moved out of the telemetry and radar acquisition processing systems super-minicomputers into user/client interactive graphic workstations. Real-time data is provided to the workstations by way of Ethernet. Future enhancement plans include use of fiber optic cable to replace the Ethernet.
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    Subject Category: 09
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    Report Date: May 1988
    No. Pages: 11
    Keywords:      Augmentation; Data processing; Display devices; Flight tests; Real time operation.
    Notes: Presented at the 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  25. WESTERN AERONAUTICAL TEST RANGE REAL-TIME GRAPHICS SOFTWARE PACKAGE MAGIC
    Authors: Jacqueline C. Malone and Archie L. Moore
    Report Number: NASA-TM-100425
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The master graphics interactive console (MAGIC) software package used on the Western Aeronautical Test Range (WATR) of the NASA Ames Research Center is described. MAGIC is a resident real-time research tool available to flight researchers-scientists in the NASA mission control centers of the WATR at the Dryden Flight Research Facility at Edwards, California. The hardware configuration and capabilities of the real-time software package are also discussed.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 31
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    Report Date: May 1988
    No. Pages: 10
    Keywords:      Applications programs (computers); Computer graphics; Consoles; Control equipment; Flight tests.


  26. DEVELOPMENT OF A MOBILE RESEARCH FLIGHT TEST SUPPORT CAPABILITY
    Authors: Donald C. Rhea and Archie L. Moore
    Report Number: NASA-TM-100428
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: This paper presents the approach taken by the NASA Western Aeronautical Test Range (WATR) of the Ames Research Center to develop and utilize mobile systems to satisfy unique real-time research flight test requirements of research projects such as the advanced fighter technology integration (AFTI)F-16, YAV-8B Harrier, F-18 high-alpha research vehicle (HARV), XV-15, and the UH-60 Black Hawk. The approach taken is cost-effective, staff efficient, technologically current, and provides a safe and effective research flight test environment to support a highly complex set of real-time requirements including the areas of tracking and data acquisition, communications (audio and video) and real-time processing and display, postmission processing, and command uplink. The development of this capability has been in response to the need for rapid deployment at varied site locations with full real-time computations and display capability. This paper will discuss the requirements, implementation and growth plan for mobile systems development within the NASA Western Aeronautical Test Range.
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    Subject Category: 04
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    Report Date: May 1988
    No. Pages: 12
    Keywords:      Control systems design; Flight tests; Ground support systems; Mobile communication systems; Research facilities.
    Notes: Presented at the 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  27. THE PC/AT COMPATIBLE COMPUTER AS A MISSION CONTROL CENTER DISPLAY PROCESSOR AT AMES-DRYDEN FLIGHT RESEARCH FACILITY
    Authors: Kevin R. Hammons
    Report Number: NASA-TM-100426
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Since 1982, the Western Aeronautical Test Range of the Ames-Dryden Flight Research Facility has been separating the data acquisition and processing function required on all telemetry pulse code modulation (PCM) data and the display processing function required in the flight research mission control centers (MCCs). These two functions historically have been done on the same set of superminicomputers remote from the MCCs. Removing the display processing function from the realm of the superminis or telemetry-radar acquisition and processing system (TRAPS) and out into the MCCs will allow the research engineers the flexibility to configure their own display processing system to optimize performance during a flight research mission. Meanwhile, the TRAPS will have more time to acquire data. One of the processors chosen is an IBM PC/AT compatible rack-mounted personal computer. This class and type machine will not only allow the transfer of the display processing function into the MCCs, but also allow the research engineers a personalized set of analytic and display tools for use on their own unique sets of data.
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    Subject Category: 60
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    Report Date: May 1988
    No. Pages: 21
    Keywords:      Compatibility; Display devices; Flight control; Flight tests; IBM computers.


  28. DEVELOPMENT OF AN INTEGRATED SET OF RESEARCH FACILITIES FOR THE SUPPORT OF RESEARCH FLIGHT TEST
    Authors: Archie L. Moore and Constance D. Harney
    Report Number: NASA-TM-100427
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The Ames-Dryden Flight Research Facility (DFRF) serves as the site for high-risk flight research on many one-of-a-kind test vehicles like the X-29A advanced technology demonstrator, F-16 advanced fighter technology integration (AFTI), AFTI F-111 mission adaptive wing, and F-18 high-alpha research vehicle (HARV). Ames-Dryden is on a section of the historic Muroc Range. The facility is oriented toward the testing of high-performance aircraft, as shown by its part in the development of the X-series aircraft. Given the cost of research flight tests and the complexity of today's systems-driven aircraft, an integrated set of ground support experimental facilities is a necessity. In support of the research flight test of highly advanced test beds, the DFRF is developing a network of facilities to expedite the acquisition and distribution of flight research data to the researcher. The network consists of an array of experimental ground-based facilities and systems as nodes and the necessary telecommunications paths to pass research data and information between these facilities. This paper presents the status of the current network, an overview of current developments, and a prospectus on future major enhancements.
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    Subject Category: 09
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    Report Date: May 1988
    No. Pages: 15
    Keywords:      Flight tests; Ground support systems; Research aircraft; Research facilities; Research management.
    Notes: Presented at the AIAA 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  29. DEVELOPMENT OF AN INTERACTIVE REAL-TIME GRAPHICS SYSTEM FOR THE DISPLAY OF VEHICLE SPACE POSITIONING
    Authors: Robert Comperini and Donald C. Rhea
    Report Number: NASA-TM-100429
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Outlined is a new approach taken by the NASA Western Aeronautical Test Range to display real-time space positioning data using computer-generated images that produce a graphic representation of an area map integrated with the research flight test aircraft track. This display system supports research flight test requirements of research projects such as the advanced fighter technology integration (AFTI) F-16, F-18 high alpha research vehicle (HARV), AFTI F-111 mission adaptive wing (MAW), F-15, and X-29A forward-swept wing. This paper will discuss the requirements, system configuration and capability, and future system applications.
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    Subject Category: 17
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    Report Date: May 1988
    No. Pages: 15
    Keywords:      Display devices; Flight paths; Mapping; Mission planning; Position indicators.
    Notes: Prepared for presentation at the 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  30. TECHNIQUES USED IN THE F-14 VARIABLE-SWEEP TRANSITION FLIGHT EXPERIMENT
    Authors: Bianca Trujillo Anderson, Robert R. Meyer, Jr. and Harry R. Chiles
    Report Number: NASA-TM-100444
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: This paper discusses and evaluates the test measurement techniques used to determine the laminar-to-turbulent boundary layer transition location in the F-14 variable-sweep transition flight experiment (VSTFE). The main objective of the VSTFE was to determine the effects of wing sweep on the laminar-to-turbulent transition location at conditions representative of transport aircraft. Four methods were used to determine the transition location: (1) a hot-film anemometer system; (2) two boundary-layer rakes; (3) surface pitot tubes; and (4) liquid crystals for flow visualization. Of the four methods, the hot-film anemometer system was the most reliable indicator of transition.
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    Subject Category: 34
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    Report Date: July 1988
    No. Pages: 25
    Keywords:      Boundary layer transition; F-14 aircraft; Flight tests; Laminar flow; Swept wings.
    Notes: Presented at the 4th AIAA Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  31. FORMULATION OF A GENERAL TECHNIQUE FOR PREDICTING PNEUMATIC ATTENUATION ERRORS IN AIRBORNE PRESSURE SENSING DEVICES
    Authors: Stephen A. Whitmore
    Report Number: NASA-TM-100430
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Presented is a mathematical model derived from the Navier-Stokes equations of momentum and continuity, which may be accurately used to predict the behavior of conventionally mounted pneumatic sensing systems subject to arbitrary pressure inputs. Numerical techniques for solving the general model are developed. Both step and frequency response lab tests were performed. These data are compared with solutions of the mathematical model and show excellent agreement. The procedures used to obtain the lab data are described. In-flight step and frequency response data were obtained. Comparisons with numerical solutions of the math model show good agreement. Procedures used to obtain the flight data are described. Difficulties encountered with obtaining the flight data are discussed.
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    Subject Category: 05
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    Report Date: May 1988
    No. Pages: 14
    Keywords:      Attenuation; Error analysis; Pneumatic probes; Predictions; Pressure measurement.
    Notes: Presented at the AIAA 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  32. CONFIGURATION MANAGEMENT ISSUES AND OBJECTIVES FOR A REAL-TIME RESEARCH FLIGHT TEST SUPPORT FACILITY
    Authors: Stephen Yergensen and Donald C. Rhea
    Report Number: NASA-TM-100437
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Presented are some of the critical issues and objectives pertaining to configuration management for the NASA Western Aeronautical Test Range (WATR) of Ames Research Center. The primary mission of the WATR is to provide a capability for the conduct of aeronautical research flight test through real-time processing and display, tracking, and communications systems. In providing this capability, the WATR must maintain and enforce a configuration management plan which is independent of, but complimentary to, various research flight test project configuration management systems. A primary WATR objective is the continued development of generic research flight test project support capability, wherein the reliability of WATR support provided to all project users is a constant priority. Therefore, the processing of configuration change requests for specific research flight test project requirements must be evaluated within a perspective that maintains this primary objective.
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    Subject Category: 59
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    Report Date: May 1988
    No. Pages: 12
    Keywords:      Aircraft configurations; Configuration management; Flight tests; Real time operation; Test facilities.
    Notes: Presented at the AIAA 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  33. EFFECT OF INTERNAL CONVECTION AND INTERNAL RADIATION ON THE STRUCTURAL TEMPERATURES OF SPACE SHUTTLE ORBITER
    Authors: William L. Ko, Robert D. Quinn and Leslie Gong
    Report Number: NASA-TM-100414
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Structural performance and resizing of the finite-element thermal analysis computer program was used in the reentry heat transfer analysis of the space shuttle orbiter. One midfuselage cross section and one midspan wing segment were selected to study the effects of internal convection and internal radiation on the structural temperatures. The effect of internal convection was found to be more prominent than that of internal radiation in the orbiter thermal analysis. Without these two effects, the calculated structural temperatures at certain stations could be as much as 45 to 90 percent higher than the measured values. By considering internal convection as free convection, the correlation between the predicted and measured structural temperatures could be improved greatly.
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    Subject Category: 34
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    Report Date: October 1988
    No. Pages: 34
    Keywords:      Air cooling; Convection; Convective heat transfer; Radiative heat transfer; Space shuttle orbiters.


  34. OPERATIONAL VIEWPOINT OF THE X-29A DIGITAL FLIGHT CONTROL SYSTEM
    Authors: Vince Chacon and David McBride
    Report Number: NASA-TM-100434
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: In the past few years many flight control systems have been implemented as full-authority, full-time digital systems. The digital design has allowed flight control systems to make use of many enhanced elements that are generally considered too complex to implement in an analog system. Examples of these elements are redundant information exchanged between channels to allow for continued operation after multiple failures and multiple variable gain schedules to optimize control of the aircraft throughout its flight envelope and in all flight modes. The introduction of the digital system for flight control also created the problem of obtaining information from the system in an understandable and useful format. This paper presents how the X-29A was dealt with during its operations at NASA Ames-Dryden Flight Research Facility. A brief description of the X-29A control system, a discussion of the tools developed to aid in daily operations, and the troubleshooting of the aircraft are included.
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    Subject Category: 05
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    Report Date: May 1988
    No. Pages: 11
    Keywords:      Digital systems; Failure modes; Flight control; Flight envelopes; X-29 aircraft.
    Notes: Presented at the ISA Aerospace Industries/Test Measurement Divisions 34th International Instrumentation Symposium, Albuquerque, N. Mex., 2-5 May 1988.


  35. PERFORMANCE IMPROVEMENTS OF AN F-15 AIRPLANE WITH AN INTEGRATED ENGINE-FLIGHT CONTROL SYSTEM
    Authors: Lawrence P. Myers and Kevin R. Walsh
    Report Number: NASA-TM-100431
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An integrated flight and propulsion control system has been developed and flight demonstrated on the NASA Ames-Dryden F-15 research aircraft. The highly integrated digital control (HIDEC) system provides additional engine thrust by increasing engine pressure ratio (EPR) at intermediate and afterburning power. The amount of EPR uptrim is modulated based on airplane maneuver requirements, flight conditions, and engine information. Engine thrust was increased as much as 10.5 percent at subsonic flight conditions by uptrimming EPR. The additional thrust significantly improved aircraft performance. Rate of climb was increased 14 percent at 40,000 ft and the time to climb from 10,000 to 40,000 ft was reduced 13 percent. A 14 and 24 percent increase in acceleration was obtained at intermediate and maximum power, respectively. The HIDEC logic performed fault free. No engine anomalies were encountered for EPR increases up to 12 percent and for angles of attack and sideslip of 32 and 11 degrees, respectively.
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    Subject Category: 07
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    Report Date: May 1988
    No. Pages: 12
    Keywords:      Aircraft performance; Control systems design; Engine tests; F-15 aircraft; Flight control.
    Notes: Presented at the AIAA 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  36. DEVELOPMENT OF A REAL-TIME AEROPERFORMANCE ANALYSIS TECHNIQUE FOR THEX-29A ADVANCED TECHNOLOGY DEMONSTRATOR
    Authors: R. J. Ray, J. W. Hicks and R. I. Alexander
    Report Number: NASA-TM-100432
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The X-29A advanced technology demonstrator has shown the practicality and advantages of the capability to compute and display, in real time, aeroperformance flight results. This capability includes the calculation of the in-flight measured drag polar, lift curve, and aircraft specific excess power. From these elements many other types of aeroperformance measurements can be computed and analyzed. The technique can be used to give an immediate postmaneuver assessment of data quality and maneuver technique, thus increasing the productivity of a flight program. A key element of this new method was the concurrent development of a real-time in-flight net thrust algorithm, based on the simplified gross thrust method. This net thrust algorithm allows for the direct calculation of total aircraft drag.
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    Subject Category: 05
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    Report Date: May 1988
    No. Pages: 18
    Keywords:      Aircraft performance; Real time operation; Research aircraft; Swept forward wings; Technology assessment.
    Notes: Prepared for presentation at the 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  37. FLIGHT TESTS OF EXTERNAL MODIFICATIONS USED TO REDUCE BLUNT BASE DRAG
    Authors: Sheryll Goecke Powers
    Report Number: NASA-TM-100433
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The effectiveness of a trailing disk (the trapped vortex concept) in reducing the blunt base drag of an 8-in diameter body of revolution was studied from measurements made both in flight and in full-scale wind-tunnel tests. The experiment demonstrated the significant base drag reduction capability of the trailing disk to Mach 0.93. The maximum base drag reduction obtained from a cavity tested on the flight body of revolution was not significant. The effectiveness of a splitter plate and a vented-wall cavity in reducing the base drag of a quasi-two-dimensional fuselage closure was studied from base pressure measurements made in flight. The fuselage closure was between the two engines of the F-111 airplane; therefore, the base pressures were in the presence of jet engine exhaust. For Mach numbers from 1.10 to 1.51, significant base drag reduction was provided by the vented-wall cavity configuration. The splitter plate was not considered effective in reducing base drag at any Mach number tested.
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    Subject Category: 02
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    Report Date: January 1988
    No. Pages: 17
    Keywords:      Aerodynamic drag; Base pressure; Blunt bodies; Drag reduction; Flight tests.
    Notes: Proposed for presentation at the AIAA 6th Applied Aerodynamics Conference, Williamsburg, Va., 6-8 Jun. 1988.


  38. THE USE OF AN AUTOMATED FLIGHT TEST MANAGEMENT SYSTEM IN THE DEVELOPMENTOF A RAPID-PROTOTYPING FLIGHT RESEARCH FACILITY
    Authors: Eugene L. Duke, Marle D. Hewett, Randal W. Brumbaugh, David M. Tartt, Robert F. Antoniewicz and Arvind K. Agarwal
    Report Number: NASA-TM-100435
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An automated flight test management system (ATMS) and its use to develop a rapid-prototyping flight research facility for artificial intelligence (AI) based flight systems concepts are described. The ATMS provides a flight test engineer with a set of tools that assist in flight planning and simulation. This system will be capable of controlling an aircraft during the flight test by performing closed-loop guidance functions, range management, and maneuver-quality monitoring. The rapid-prototyping flight research facility is being developed at the Dryden Flight Research Facility of the NASA Ames Research Center (Ames-Dryden) to provide early flight assessment of emerging AI technology. The facility is being developed as one element of the aircraft automation program which focuses on the qualification and validation of embedded real-time AI-based systems.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 62
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    Report Date: May 1988
    No. Pages: 21
    Keywords:      Artificial intelligence; Automatic control; Expert systems; Flight tests; Prototypes.
    Notes: Presented at the 4th Conference on Artificial Intelligence Applications, Long Beach, Calif., 4-6 May 1988.


  39. SURFACE FLOW VISUALIZATION OF SEPARATED FLOWS ON THE FOREBODY OF AN F-18AIRCRAFT AND WIND-TUNNEL MODEL
    Authors: David F. Fisher, David M. Richwine and Daniel W. Banks
    Report Number: NASA-TM-100436
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A method of in-flight surface flow visualization similar to wind-tunnel-model oil flows is described for cases where photo-chase planes or onboard photography are not practical. This method, used on an F-18 aircraft in flight at high angles of attack, clearly showed surface flow streamlines in the fuselage forebody. Vortex separation and reattachment lines were identified with this method and documented using postflight photography. Surface flow angles measured at the 90 and 270 degrees meridians show excellent agreement with the wind tunnel data for a pointed tangent ogive with an aspect ratio of 3.5. The separation and reattachment line locations were qualitatively similar to the F-18 wind-tunnel-model oil flows but neither the laminar separation bubble nor the boundary-layer transition on the wind tunnel model were evident in the flight surface flows. The separation and reattachment line locations were in fair agreement with the wind tunnel data for the 3.5 ogive. The elliptical forebody shape of the F-18 caused the primary separation lines to move toward the leeward meridian. Little effect of angle of attack on the separation locations was noted for the range reported.
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    Subject Category: 02
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    Report Date: May 1988
    No. Pages: 20
    Keywords:      Angle of attack; Boundary layer flow; F-18 aircraft; Flow visualization; Forebodies.


  40. FLIGHT RESEARCH AND TESTING
    Authors: Terrill W. Putnam and Theodore G. Ayers
    Report Number: NASA-TM-100439
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Flight research and testing form a critical link in the aeronautic R and D chain. Brilliant concepts, elegant theories, and even sophisticated ground tests of flight vehicles are not sufficient to prove beyond doubt that an unproven aeronautical concept will actually perform as predicted. Flight research and testing provide the ultimate proof that an idea or concept performs as expected. Ever since the Wright brothers, flight research and testing have been the crucible in which aeronautical concepts have advanced and been proven to the point that engineers and companies have been willing to stake their future to produce and design new aircraft. This is still true today, as shown by the development of the experimental X-30 aerospace plane. The Dryden Flight Research Center (Ames-Dryden) continues to be involved in a number of flight research programs that require understanding and characterization of the total airplane in all the aeronautical disciplines, for example the X-29. Other programs such as the F-14 variable-sweep transition flight experiment have focused on a single concept or discipline. Ames-Dryden also continues to conduct flight and ground based experiments to improve and expand the ability to test and evaluate advanced aeronautical concepts. A review of significant aeronautical flight research programs and experiments is presented to illustrate both the progress made and the challenges to come.
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    Subject Category: 05
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    Report Date: June 1988
    No. Pages: 24
    Keywords:      Aeronautical engineering; Aerospace planes; Aircraft design; Flight tests; Research management.
    Notes: Presented at the Transonic Symposium, Hampton, Va., Apr. 1988.


  41. IN-FLIGHT RAIN DAMAGE TESTS OF THE SHUTTLE THERMAL PROTECTION SYSTEM
    Authors: Robert R. Meyer, Jr. and Jack Barneburg
    Report Number: NASA-TM-100438
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: NASA conducted in-flight rain damage tests of the Shuttle thermal protection system (TPS). Most of the tests were conducted on an F-104 aircraft at the Dryden Flight Research Facility of NASA's Ames Research Center, although some tests were conducted by NOAA on a WP-3D aircraft off the eastern coast of southern Florida. The TPS components tested included LI900 and LI2200 tiles, advanced flexible reusable surface insulation, reinforced carbon-carbon, and an advanced tufi tile. The objective of the test was to define the damage threshold of various thermal protection materials during flight through rain. The test hardware, test technique, and results from both F-104 and WP-3D aircraft are described. Results have shown that damage can occur to the Shuttle TPS during flight in rain.
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    Subject Category: 18
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    Report Date: May 1988
    No. Pages: 16
    Keywords:      Carbon-carbon composites; Rain impact damage; Space shuttles; Thermal protection; Tiles
    Notes: Presented at the 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  42. CONSTRUCTING GLOVED WINGS FOR AERODYNAMIC STUDIES
    Authors: Marta R. Bohn-Meyer
    Report Number: NASA-TM-100440
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Recently, two aircraft from the Dryden Flight Research Facility were used in the general study of natural laminar flow (NLF). The first, an F-14A aircraft on short-term loan from the Navy, was used to investigate transonic natural laminar flow. The second, an F-15A aircraft on long-term loan from the Air Force, was used to examine supersonic NLF. These tests were follow-on experiments to the NASA F-111 NLF experiment conducted in 1979. Both wings of the F-14A were gloved, in a two-phased experiment, with full-span(upper surface only) airfoil shapes constructed primarily of fiberglass, foam, and resin. A small section of the F-15A right wing was gloved in a similar manner. Each glove incorporated provisions for instrumentation to measure surface pressure distributions. The F-14A gloves also had provisions for instrumentation to measure boundary layer profiles, acoustic environments, and surface pitot pressures. Discussions of the techniques used to construct the gloves and to incorporate the required instrumentation are presented.
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    Subject Category: 02
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    Report Date: May 1988
    No. Pages: 20
    Keywords:      Aerodynamic coefficients; Airfoils; Gloves; Laminar flow; Wings.
    Notes: Presented at the 4th Flight Test Conference, San Diego, Calif., 18-20 May 1988.


  43. LONGITUDINAL LONG-PERIOD DYNAMICS OF AEROSPACE CRAFT
    Authors: Donald T. Berry
    Report Number: H-1491
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Linear analyses are performed to examine the generic aspects of aerospace vehicle longitudinal long-period or trajectory modes of motion. The influence of Mach number, dynamic pressure, thrust-to-drag ratio, and propulsion system thrust laws on the longitudinal trajectory modes is presented in terms of phugoid frequency and damping and height mode stability. The results of these analyses are compared to flying qualities requirements where possible, and potential deficiencies in both the vehicle and the criteria are noted. A preliminary look at possible augmentation schemes to improve potential deficiencies is also presented. Interpretation of the practical consequences of the results is aided by typical time histories. Results indicate that propulsion system characteristics are the dominant influence on the longitudinal long-period flight dynamics of hypersonic aerospace craft. However, straightforward augmentation systems demonstrated the potential to accommodate these influences if the effects are included in the design process. These efforts may be hampered by a lack of design criteria for hypersonic aircraft.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 08
    Availability:

    From NTRS: Locate an electronic (PDF) copy of the document.
    Report Date: January 1988
    No. Pages: 11
    Keywords:      Aerospace planes; Aircraft control; Flight characteristics; Propulsion system configurations; Trajectory analysis.
    Notes: IN: AIAA Atmospheric Flight Mechanics Conference, Minneapolis, MN, Aug. 15-17, 1988, Technical Papers. Washington, DC, American Institute of Aeronautics and Astronautics, 1988, p. 254-264. AIAA Paper 88-4358.


  44. CONTROL SURFACE SPANWISE PLACEMENT IN ACTIVE FLUTTER SUPPRESSION SYSTEMS
    Authors: E. Nissim and John J. Burken
    Report Number: NASA-TP-2873
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A method is developed that determines the placement of an active control surface for maximum effectiveness in suppressing flutter. No specific control law is required by this method which is based on the aerodynamic energy concept. It is argued that the spanwise placement of the active controls should coincide with the locations where maximum energy per unit span is fed into the system. The method enables one to determine the distribution, over the different surfaces of the aircraft, of the energy input into the system as a result of the unstable fluttering mode. The method is illustrated using three numerical examples.
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    Subject Category: 39
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    Report Date: November 1988
    No. Pages: 19
    Keywords:      Active control; Aerodynamics; Aeroelasticity; Control surfaces; Flutter analysis.
    Notes: Prepared in cooperation with Technion - Israel Inst. of Tech., Haifa.


  45. APPLICATION OF FLIGHT SYSTEMS METHODOLOGIES TO THE VALIDATION OFKNOWLEDGE-BASED SYSTEMS
    Authors: Eugene L. Duke
    Report Number: NASA-TM-100442
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Flight and mission-critical systems are verified, qualified for flight, and validated using well-known and well-established techniques. These techniques define the validation methodology used for such systems. In order to verify, qualify, and validate knowledge-based systems (KBS's), the methodology used for conventional systems must be addressed, and the applicability and limitations of that methodology to KBS's must be identified. The author presents an outline of how this approach to the validation of KBS's is being developed and used at the Dryden Flight Research Facility of the NASA Ames Research Center.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 63
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    Report Date: July 1988
    No. Pages: 19
    Keywords:      Artificial intelligence; Expert systems; Flight management systems; Knowledge representation; Proving.
    Notes: Presented at the Space Operations Automation and Robotics (SOAR) Workshop, Dayton, Ohio, 20-23 Jul. 1988.


  46. MEASURED AND PREDICTED PRESSURE DISTRIBUTIONS ON THE AFTI/F-111 MISSIONADAPTIVE WING
    Authors: Lannie D. Webb, William E. McCain and Lucinda A. Rose
    Report Number: NASA-TM-100443
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Flight tests have been conducted using an F-111 aircraft modified with a mission adaptive wing (MAW). The MAW has variable-camber leading and trailing edge surfaces that can change the wing camber in flight, while preserving smooth upper surface contours. This paper contains wing surface pressure measurements obtained during flight tests at Dryden Flight Research Facility of NASA Ames Research Center. Upper and lower surface steady pressure distributions were measured along four streamwise rows of static pressure orifices on the right wing for a leading-edge sweep angle of 26 deg. The airplane, wing, instrumentation, and test conditions are discussed. Steady pressure results are presented for selected wing camber deflections flown at subsonic Mach numbers up to 0.90 and an angle-of-attack range of 5 to 12 deg. The Reynolds number was 26 million, based on the mean aerodynamic chord. The MAW flight data are compared to MAW wind tunnel data, transonic aircraft technology (TACT) flight data, and predicted pressure distributions. The results provide a unique database for a smooth, variable-camber, advanced supercritical wing.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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    Report Date: November 1988
    No. Pages: 20
    Keywords:      Cambered wings; F-111 aircraft; Mission adaptive wings; Pressure distribution; Variability.
    Notes: Presented at the 6th Applied Aerodynamics Conference, Williamsburg, VA, 6-8 Jun. 1988.


  47. CURRENT FLIGHT TEST EXPERIENCE RELATED TO STRUCTURAL DIVERGENCE OFFORWARD-SWEPT WINGS
    Authors: Lawrence S. Schuster and William A. Lokos
    Report Number: NASA-TM-100445
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Flight testing the X-29A forward-swept wing aircraft has required development of new flight test techniques to accomplish subcritical extrapolations to the actual structural divergence dynamic pressure of the aircraft. This paper provides current experience related to applying these techniques to analysis of flight data from the forward-swept wing in order to assess the applicability of these techniques to flight test data. The measurements required, maneuvers flown, and flight test conditions are described. Supporting analytical predictions for the techniques are described and the results using flight data are compared to these predictions. Use of the results during envelope expansion and the resulting modifications to the techniques are discussed. Some of the analysis challenges that occurred are addressed and some preliminary conclusions and recommendations are made relative to the usefulness of these techniques in the flight test environment.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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    Report Date: August 1988
    No. Pages: 15
    Keywords:      Divergence; Dynamic structural analysis; Flight envelopes; Flight tests; Swept forward wings.
    Notes: Presented at the 1988 International Symposium of Flight Test Engineers, Arlington, Tex., 14-18 Aug. 1988


  48. THE EFFECTS OF EXCITATION WAVEFORMS AND SHAKER MOVING MASS ON THE MEASURED MODAL CHARACTERISTICS OF A 2- BY 5-FOOT ALUMINUM PLATE
    Authors: David F. Voracek and Adolfo M. Morales
    Report Number: NASA-TM-100446
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Ground vibration tests were conducted to compare and to investigate the effects of five excitation waveforms and the shaker moving mass (equipment and armature used to attach the shaker to the structure) on the experimental modal characteristics of a 2- by 5-ft aluminum plate using fast Fourier transform techniques. The five types of excitation waveforms studied were sine dwell, random, impact, sine sweep, and impulsive sine. The results showed that the experimental modal frequencies for all types of excitation were within 3 percent, while the modal damping data exhibited greater scatter. The sets of mode shapes obtained by the five types of excitation were consistent. The results of the shaker moving mass investigation on the 2- by 5-ft aluminum plate showed that modal frequency decreases and modal damping remains relatively constant with an increase in shaker moving mass. The generalized mass of the structure appears to decrease with an increase in shaker moving mass. In addition, it was seen that having a shaker near a node line can reduce some of the effects of the added shaker moving mass on the frequencies and the damping.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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    Report Date: December 1988
    No. Pages: 24
    Keywords:      Aluminum; Excitation; Mass; Motion; Plates.


  49. THE PSYCHOLOGY OF COMPUTER DISPLAYS IN THE MODERN MISSION CONTROL CENTER
    Authors: Michael M. Granaas and Donald C. Rhea
    Report Number: NASA-TM-100451
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Work at NASA's Western Aeronautical Test Range (WATR) has demonstrated the need for increased consideration of psychological factors in the design of computer displays for the WATR mission control center. These factors include color perception, memory load, and cognitive processing abilities. A review of relevant work in the human factors psychology area is provided to demonstrate the need for this awareness. The information provided should be relevant in control room settings where computerized displays are being used.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 53
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    Report Date: October 1988
    No. Pages: 6
    Keywords:      Computer graphics; Display devices; Human factors engineering; Psychological factors; Test ranges.


  50. AN AIRBORNE SYSTEM FOR VORTEX FLOW VISUALIZATION ON THE F-18 HIGH-ALPHA RESEARCH VEHICLE
    Authors: Robert E. Curry and David M. Richwine
    Report Number: H-1509
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A flow visualization system for the F-18 high-alpha research vehicle is described which allows direct observation of the separated vortex flows over a wide range of flight conditions. The system consists of a smoke generator system, on-board photographic and video systems, and instrumentation. In the present concept, smoke is entrained into the low-pressure vortex core, and vortice breakdown is indicated by a rapid diffusion of the smoke. The resulting pattern is observed using photographic and video images and is correlated with measured flight conditions.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 06
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    From NTRS: Locate an electronic (PDF) copy of the document.
    Report Date: September 1988
    No. Pages: 13
    Keywords:      Airborne equipment; Angle of attack; F-18 aircraft; Flow visualization; Research vehicles.
    Notes: AIAA, NASA, and AFWAL, Conference on Sensors and Measurement Techniques for Aeronautical Applications, Atlanta, GA, Sept. 7-9, 1988. 13 p. AIAA Paper 88-4671.


  51. REAL-TIME FLIGHT TEST ANALYSIS AND DISPLAY TECHNIQUES FOR THE X-29A AIRCRAFT
    Authors: John W. Hicks and Kevin L. Petersen
    Report Number: NASA-TM-101692
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The X-29A advanced technology demonstrator flight envelope expansion program and the subsequent flight research phase gave impetus to the development of several innovative real-time analysis and display techniques. These new techniques produced significant improvements in flight test productivity, flight research capabilities, and flight safety. These techniques include real-time measurement and display of in-flight structural loads, dynamic structural mode frequency and damping, flight control system dynamic stability and control response, aeroperformance drag polars, and aircraft specific excess power. Several of these analysis techniques also provided for direct comparisons of flight-measured results with analytical predictions. The aeroperformance technique was made possible by the concurrent development of a new simplified in-flight net thrust computation method. To achieve these levels of on-line flight test analysis, integration of ground and airborne systems was required. The capability of NASA Ames Research Center, Dryden Flight Research Facility's Western Aeronautical Test Range was a key factor in enabling implementation of these methods.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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    Report Date: November 1988
    No. Pages: 20
    Keywords:      Display devices; Flight envelopes; Flight tests; Real time operation; X-29 aircraft.
    Notes: Presented at the 73rd Flight Test Techniques Symposium Flight Mechanics Panel, Edwards AFB, Calif., 17-20 Oct. 1988 Flight Test Techniques Symposium Flight Mechanics Panel Edwards AFB, CA 17-20 Oct. 1988.


  52. FLOW VISUALIZATION TECHNIQUES FOR FLIGHT RESEARCH
    Authors: David F. Fisher and Robert R. Meyer, Jr.
    Report Number: NASA-TM-100455
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: In-flight flow visualization techniques used at the Dryden Flight Research Facility of NASA Ames Research Center (Ames-Dryden) and its predecessor organizations are described. Results from flight tests which visualized surface flows using flow cones, tufts, oil flows, liquid crystals, sublimating chemicals, and emitted fluids have been obtained. Off-surface flow visualization of vortical flow has been obtained from natural condensation and two methods using smoke generator systems. Recent results from flight tests at NASA Langley Research Center using a propylene glycol smoker and an infrared imager are also included. Results from photo-chase aircraft, onboard and postflight photography are presented.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 02
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    Report Date: October 1988
    No. Pages: 35
    Keywords:      Flight tests; Flow distribution; Flow visualization; In-flight monitoring; Liquid crystals.
    Notes: Presented at the 73rd AGARD Symposium of the Flight Mechanics Panel on Flight Test Techniques, Edwards AFB, Calif., 17-20 Oct. 1988 AGARD Symposium of the Flight Mechanics Panel on Flight Test Techniques Edwards AFB, CA 17-20 Oct. 1988.
 
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