Backdrive control system for aircraft flight control surfaces

A backdrive system for aircraft flight control surfaces and the like, comprising:

• motive means for driving a control surface;
• fluid pressure responsive clutch means operatively associated between the motive means and the control surface, the clutch means being disengaged in the presence of fluid pressure;
• fluid pressure supply means connected to the clutch means;
• accumulator means connected in-line between the supply means and the clutch means for storing hydraulic energy during normal operation of the system and for releasing the stored hydraulic energy for at least a given period of time in the event of loss of supply pressure to allow the control surface to backdrive to a neutral position;
• and
• check-valve means between the fluid pressure supply means and the accumulator means to prevent return of hydraulic energy from the accumulator means to the fluid pressure supply means in the event of loss of the supply pressure.

A backdrive system for aircraft flight control surfaces and the like, comprising:

• motive means for driving a control surface;
• fluid pressure responsive brake means operatively associated between the motive means and the control surface, the brake means being released in the presence of fluid pressure;
• fluid pressure supply means connected to the brake means;
• accumulator means connected in-line between the supply means and the brake means for storing hydraulic energy during normal operation of the system and for releasing the stored hydraulic energy for at least a given period of time in the event of loss of supply pressure to allow the control surface to backdrive to a neutral position;
• and
• check-valve means between the fluid pressure supply means and the accumulator means to prevent return of hydraulic energy from the accumulator means to the fluid pressure supply means in the event of loss of the supply pressure.