Towards In-Flight Detection and Accommodation of Faults in Aircraft Engines

To effectively accommodate safety-critical faults in-flight it is necessary to rapidly detect them and to have a means to accommodate the fault. We present results on model-based fault detection using sensor residuals from an extended Kalman filter with an embedded real-time engine model to characterize un-faulted behavior over the flight envelope. Thereafter, we present an approach for online fault accommodation via optimal changes in a set of suitable adjustments in the existing FADEC control logic. These optimal adjustments are obtained through off-line optimization for recovery of stall margins and thrust, then interpolated online for the existing flight conditions. We present results of the fault detection & accommodation applied to a high-bypass commercial aircraft engine over the flight envelope.