Control Loss Recovery Autopilot Design for Fixed-Wing Aircraft

In this paper a loop-shaping design approach is investigated for distressed fixed-wing aircraft experiencing control loss due to surface or power failure. An accurate nonlinear model of the aircraft dynamics is utilized to obtain a target aircraft behavior in the emergency situation, for which a loop-shaping controller is designed to balance performance and robustness, and to decouple different command channels. A rudder servoactuator jam scenario is presented as an example where it is seen that the autopilot recovers level flight and responds well to fly-by-wire commands from the operator.