APPARATUS AND METHODS FOR APPORTIONING COMMANDS BETWEEN AIRCRAFT FLIGHT CONTROL SURFACES

A controller for apportioning high amplitude and low amplitude control signals between two aircraft control surfaces, such as for example, between an elevator and an associated movable horizontal stabilizer. The signals are separated along a first path and a second path. Signals along the first path are fed to a low pass filter where the low frequency signals are separated and an elevator position error signal is generated. Those signals exceeding a predetermined elevator position error are fed in the form of stabilizer rate signals to a stabilizer position module where a stabilizer positioning signal is generated and then fed to a stabilizer servo system to reposition the horizontal stabilizer. The stabilizer positioning signal is also fed to a multiplier where it is multiplied by a predetermined pitch effectiveness ratio representing the amount of elevator deflection required to achieve the same pitch moment as one degree of stabilizer deflection. The resulting multiplied signal is subtracted from control signals along the second path to generate an elevator positioning signal which is fed to an elevator servo system to reposition the elevator.