Post-Damage Reconfiguration for High-Speed Rotorcraft with Control Redundancy

Aircraft survivability is a critical consideration in control system and overall aircraft design. The ability of an aircraft to withstand some form of damage to a control effector is essential in aircraft recovery, crew safety, and mission completion when possible. Control redundancy plays a key role in the ability of an aircraft to tolerate damage and remain operational. In rotary wing aircraft, high-speed configurations such as coaxial and compound helicopter variants possess such redundancies that may enable reconfiguration of the aircraft flight controls in the event of component degradation or failure. This project examines in detail robust control and control reconfiguration strategies that can tolerate damage/failure/degradation in various control effectors on high-speed VTOL aircraft with control redundancy.  Some considered methods for control reconfiguration include the explicit ganging of redundant control effectors in the primary flight controller feedback loop, both before and after the fault type has been identified.

As a first step, use of the horizontal tail on the UH-60 Black Hawk helicopter for pitch attitude control was shown to be an adequate in the event of swashplate forward or aft servo failure.

NRTC (VLRCOE program)