AIRCRAFT SHORT-TERM ROLL ATTITUDE RETENTION SYSTEM

An automatic flight control system, for an aircraft having a roll attitude retention outer loop actuator (29), a roll stability inner loop actuator (25) and a control stick (26) for positioning control surfaces of the aircraft to control its roll attitude, includes means (54, 55) to provide a roll error signal (56) indicative of the deviation in roll attitude from a desired roll attitude. The roll attitude retention outer loop actuator (29) is controlled by a proportional (61) and integral (62) function of the roll error when force is not applied to the stick, but only as a proportional function when force is applied to the stick (48, 49, 51, 62). The roll stability inner loop actuator is controlled by a washed out (72) proportional (64) function of the roll error signal to provide short-term roll retention at roll attitudes established by the control stick during turns against trim. Sensing force on the stick (51, 95, FIG. 1) and roll attitude of a predetermined threshold magnitude (107) provides adjustments in relative gain (113, 117, 70, 71, FIG. 1; 154, 157, 160-163, FIG. 4) during turns against trim.