FLIGHT INVESTIGATION OF A CENTRALLY LOCATED RIGID FORCE CONTROL STICK USED WITH ELECTRONIC CONTROL SYSTEMS IN A FIGHTER AIRPLANE

摘要

A flight investigation was made to evaluate a rigid, nonmoving, centrally located force stick as a maneuvering flight controller for a fighter airplane. The force stick was similar in size and location to a conventional control stick and was used with both a rate-type command control system and an irreversible electronic power control system. Included in the flying were pullups, turns, aileron rolls, rough-air flying, stall approaches, and landings.nIn the opinion of the pilots the centrally located rigid force stick was not as suitable for use as a maneuvering controller for a fighter airplane as a displacement-type control stick. Although the pilots did not find the lack of stick displacement to be greatly objectionable, they were of the opinion that some stick motion was desirable.nThe longitudinal control characteristics were satisfactory. No longitudinal sensitivity problems were encountered. The pilots preferred a stick force gradient of about 5 pounds per g except at indicated airspeeds below 150 knots where the preferred force gradient was slightly higher.nThe lateral control characteristics generally were unsatisfactory. At indicated airspeeds above 150 knots the pilots found it difficult to maintain a constant rolling velocity. The undesired rolling motions were evident primarily as low-amplitude variations in rolling acceleration. The undesired rolling accelerations were annoying to the pilot and made precision flying difficult. They resulted from the lack of stick displacement, lack of stick ffraction and the short response time of the control-system—airplane combination.