Flexible shafts transmit rotary motion much like a solid shaft, but can be routed over, under and around obstacles where a solid shaft cannot be used. Flexible shafts are used in a variety of applications, including many capacities in aerospace, such as in thrust reverser actuation systems (TRAS), flap and slat systems, variable bleed valves, jet afterburner nozzle control systems, cargo door actuation systems, valve override and many more.
While used in many systems on various aircraft, one significant aerospace application is to manually actuate valves if the automatic system in place were to fail. Any number of valves may be manually actuated using a flexible shaft assembly, including Air Turbine Starter (ATS) and anti-ice valves, as well as those applications mentioned above. The ability to control the valves manually in the event of the automated system’s failure means the aircraft can still be safely ‘dispatched’ on time, avoiding the time and costs associated with having to find a substitute aircraft.
