Accession Number:

ADP004100

Title:

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

Descriptive Note:

Corporate Author:

AIR FORCE FLIGHT TEST CENTER EDWARDS AFB CA

Personal Author(s):

Report Date:

1984-07-01

Pagination or Media Count:

13.0

Abstract:

The implementation of USAF StallPost-stallSpin Flight Test Demonstration Specification, MIL-S-83691, in the early 1970s, introduced major changes to the techniques used at the AFFTC in test and evaluation of maneuvering-type military aircraft near stalldeparture 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.

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE