Abstract: An aircraft pitch attitude stabilization system that utilizes an engine pressure ratio signal to cancel pitching moments due to changes in engine thrust. The changes in the engine pressure ratio signals which result from thrust changes are used to generate a pitch stabilization signal that is combined with other pitch control signals to automatically counteract pitching moments resulting from the changes in engine thrust.

Abstract: A pilot controlled stability control system that employs direct lift control (spoiler control) with elevator control to control the flight path angle of an aircraft. A computer on the aircraft generates an elevator control signal and a spoiler control signal, using a pilot-controlled pitch control signal and pitch rate, vertical velocity, roll angle, groundspeed, engine pressure ratio and vertical acceleration signals which are generated on the aircraft. The direct lift control by the aircraft spoilers improves the response of the aircraft flight path angle and provides short term flight path stabilization against environmental disturbances.