A Piloted Evaluation of an Oblique-Wing Research Aircraft Motion Simulation With Decoupling Control Laws

Kempel, Robert W. and McNeill, Walter E. and Gilyard, Glenn B. and Maine, Trindel A. (1988) A Piloted Evaluation of an Oblique-Wing Research Aircraft Motion Simulation With Decoupling Control Laws. Technical Report NASA TP-2874, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

The NASA Ames Research Center developed an oblique-wing research airplane from NASA's F-8 digital-fly-by-wire airplane. Oblique-wing airplanes show large cross-coupling in control and dynamic behavior which is not present in 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 sideforce 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.

EPrint Type:	NASA Technical Publication
Keywords:	Asymmetric aircraft, Flight controls, Simulation
Subjects:	Aircraft/Project: Nonaircraft-specific (01 - 09) Aeronautics: (08) Aircraft Stability And Control
ID Code:	427
Deposited On:	05 April 2005
Additional Information:	52 pages.