Apparatus for use on an aircraft

摘要

An actuator is arranged to move an aircraft component such as a landing gear leg, flap or aileron between a first position and a second position, net load from external forces acting on the aircraft component tending to drive it towards the first position. The actuator comprises a threaded screw and a threaded nut. A main prime mover is configured to apply torque to the screw or nut acting in opposition to the net load under normal operating conditions. An emergency prime mover is configured to apply torque to the screw or nut acting in the same sense as the net load under emergency operating conditions in which the interface between the nut and the screw has become partially jammed to the extent that the component cannot be moved from the second position to the first position by operation of the net load alone.

主权项

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.