The Boeing Company
Electro-mechanically biased supercritical flight control surface loading to reduce high pressure actuation cycles

Abstract:

An actuator assembly for an aircraft includes a support strut operatively coupled to a hinge axis of a flight control member of the aircraft, a hydraulic actuator operatively coupled to the flight control member via a pivot element, and an electro-mechanical actuator (EMA) having first and second opposing ends and a biasing member. The first end is operatively coupled to a support structure of the aircraft, and the second end is operatively coupled to both the support strut and the hydraulic actuator. The biasing member moves between a compressed state and an expanded state in response to a varying biasing load exerted on a surface of the flight control member, thereby reducing an amount of current needed to drive the EMA, as well as a number of high-pressure hydraulic cycles of the hydraulic actuator to control the flight control member.