Abstract: The fault diagnosis technology of the flight electromechanical actuation system is of great

significance to improve the reliability of the aircraft actuation system and ensure the safe operation of the aircraft.

Considering the problems and challenges encountered in the application of fault diagnosis technology in the flight

electromechanical actuation system，the research status and developments of fault diagnosis technology in the flight electromechanical actuator system were firstly introduced. After that，special attention was paid to the limitations of novel faults and closed-loop control on the development of fault diagnosis technology，as well as the challenges of fault diagnosis technology validation and verification. Beyond that，the problems to be solved urgently and possible research directions of the fault diagnosis technology in the flight electromechanical actuation system were discussed as well in this work.

      Key words: flight electromechanical actuation system；reliability；fault diagnosis；fault detecting；airworthiness certification