Accession Number : ADP004100

Title :   High Angle of Attack Test and Evaluation Techniques for the 1980s,

Corporate Author : AIR FORCE FLIGHT TEST CENTER EDWARDS AFB CA

Personal Author(s) : Jones,G. L.

Report Date : JUL 1984

Pagination or Media Count : 13

Abstract : The implementation of USAF Stall/Post-stall/Spin Flight Test Demonstration Specification, MIL-S-83691, in the early 1970's, introduced major changes to the techniques used at the AFFTC in test and evaluation of maneuvering-type military aircraft near stall/departure angles of attack. Since then the basic objectives of each high AOA flight test program have been the determination of departure characteristics and the development of methods for departure prevention and spin avoidance. Along with the emphasis on departure prevention came increased attention to flight dynamic prediction methods and an increased use of open-loop and pilot-in-the-loop simulations which are continually updated to stay abreast of the flight test program and to assist in flight planning. The highly nonlinear and complex nature of aircraft dynamic behavior at high AOA coupled with poorly understood aerodynamics has made this task difficult. One additional factor that aggravates the problem of correlating flight test results with wind tunnel and simulator predictions is that airspeed, AOA and angle of sideslip, measured onboard the flight test aircraft by means of noseboom pitot-static and vane sensors, yield erroneous and misleading information at high AOA. State-of-the-art inertial navigation systems, however, have recently provided a tool to accurately determine these parameter values and to do a considerably better job of correlating flight test results with predictions, allowing improved estimates of aircraft dynamic characteristics at more adverse flight conditions.

Descriptors :   *Attitude control systems, *Angle of attack, High angles, Aerodynamic characteristics, Data acquisition, Flight maneuvers, Military aircraft, Stalling, Adverse conditions, Flight envelope, Flight testing, Spinning(Motion), Prevention, Avoidance, Recovery, Pilots, Man machine systems, Flight simulation, Wind tunnel tests, Experimental data, Correlation

Distribution Statement : APPROVED FOR PUBLIC RELEASE