Abstract:

Aero-engine fault diagnosis based on gas line parameters is a simple,economical,effective and practical fault diagnosis method. But since the engine baseline hidden in the monitoring system of the engine manufacturer,and it is not available to users,so self-monitoring and diagnosis for users is limited. Starting from the concept of baseline,a method based on monitoring of twin differences is raised to achieve fault diagnosis with differences between the two engines on one plane instead of the deviation between actual data and baseline values. QAR (quick access recorder)as a widely used data access system at present provides accurate and valid data to support aero-engine fault diagnosis.

Key words: fault diagnosis, aero-engine, QAR, finger print, baseline, monitoring of twin differences