Abstract: The technology of condition monitoring and health management is the breakthrough key technical of the domestic civil aircraft operators support. With civil aircraft bleed air system as the object of the research，a fault detection process based on flight data is designed and a method of fault detection for civil aircraft bleed air systems are proposed by the same state data extraction using bayesian network classification and exponentially weighted moving average control chart. The method is validated by using actual data collected in airline.The results show that the proposed method not only can detect fault for civil aircraft bleed air system, but also found fault ahead of time, which provides support for the airline to arrange aircraft maintenance programs reasonably, reduces aircraft downtime.

Key words: Aircraft bleed air system, Flight data, Fault detection, Bayesian network, EWMA control chart