Trim augmentation system for a rotary wing aircraft

Abstract

The flight control system includes a trim augmentation algorithm which advantageously provides two primary functions: direct augmentation of the rotor trim via on-axis stick input; and automatic cross-axis trim transfer as a function of the commanded yaw rate. In a first function of the present invention, when the aircraft is lagging the pilots commanded maneuver state the stick command is multiplied by a gain to direct the actual vehicle response toward said pilot commanded rate signal and improve the model following control laws. In a second function of the present invention, a cross-axis trim transfer function of the trim augmentation algorithm uses the commanded yaw rate to anticipate the trim change when the aircraft is rotating in winds. When a yaw maneuver is performed, the cross-axis trim transfer function automatically “stirs” the cyclic as the aircraft rotates about the yaw axis.

Dependencies are inferred from the claim text.