Combining aerothermodynamics theory with engineering problems in the airworthiness field

the representative destabilizing factors of engine surge and stall characteristics were investigated systematically. A fast method of surge/stall margin prediction was established

based on which the destabilizing factors and their laws of JT9D engine model were studied. Results showed that the most important factor affecting the stability margin of fan components was distortion

and the most important factor affecting the stability margin of booster stage and high-pressure compressor was structural decay during the lifetime. The related key elements of CCAR 3365 compliance verification activities have been confirmed. The compliance verification process of CCAR 3365 has been improved

providing a technical support for airworthiness certification ability improvement.