US Patent 7137595 Flight lock actuator with dual energy sources

A flight lock actuator that can be powered by two sources of stored energy when aircraft power has been switched off. A mechanical energy storage means and an electrical energy storage means provide a fully redundant energy storage system that stores sufficient energy to complete the actuator's extension stroke when aircraft power is removed. The actuator has a motor control system that limits the stroke velocity for both the extension and retraction strokes, including a damper feature capable of effectively braking the actuator during the back-driven extension stroke.