Patent ID: 9162751
Filing Date: 2015-10-20
Classification: B64C,F16H,Y10T

Abstract:
1. Apparatus for use on an aircraft, the apparatus comprising: a component; an actuator arranged to move the component between a first position and a second position, net load from external forces acting on the component tending to drive it towards the first position, wherein the actuator comprises: a threaded screw; a threaded nut; a main prime mover coupled to said screw or said nut in order to impart relative linear motion between the screw and the nut; an emergency prime mover coupled to said screw or said nut in order to impart relative linear motion between the screw and the nut; a normal control system configured to energise the main prime mover under normal operating conditions so that it applies torque to the screw or nut acting in opposition to the net load; and an emergency control system configured to energise the emergency prime mover under emergency operating conditions so that it applies torque to the screw or nut acting in the same sense as the net load thereby driving the component to the first position, wherein the emergency control system is configured so that under the normal operating conditions the emergency prime mover is not energized by the emergency control system to apply torque to the screw or nut.