Adual Kalman filter based health parameters estimation technique was proposed to conduct fault diagnosis of aeroengine components and sensors.Unsteady engine operation measurements were used to solve the diagnosis problem caused by limited amount of available sensors.The reduced sigma point square root unscented Kalman filter(UKF) algorithm could improve the filtering stability and decrease the computational cost greatly.Afault diagnostic simulation was carried out for two-spool turbofan engine components and sensors

showing that the dual Kalman filtering algorithm is an effective aeroengine diagnostic technique.