Patent US 4,649,484

An all-electric powered flight control system for an aircraft incorporating fault-tolerant avionics combined with a redundant power actuation control system utilizing electro-mechanical devices for actuating aerodynamic control surfaces; and wherein, the redundancy is implemented through the division of the total aerodynamic surface area to be actuated into multi-segments, with each control segment having its own channel in the avionic control system. The avionic control system is effective in minimizing the effects of power actuated control loads reacting through aircraft structure by the incorporation of an electronic gain control power module which is positioned between the power output side of an actuator (e.g., an electro-mechanical or electro-hydraulic device) and the aerodynamic control surface or segment being actuated. Further, the avionic control system includes means for passivating a single control segment of the multi-segmented aerodynamic control surface upon the malfunction of either its avionic control channel or its power actuator output.