Detection of Incipient Bearing Faults in Gas Turbine Engines

Development of robust and highly sensitive algorithms for detecting incipient bearing faults in gas turbine engines will greatly benefit both military and civil aviation through improved aircraft reliability and maintainability. Techniques including advanced vibration analysis and oil debris monitoring have proven effective in laboratory and industrial settings, but factors including poor transmission of vibration energy from bearings to practical sensor locations and settling of debris in oil scavenge lines have complicated implementation of these techniques in operational gas turbine engines. In this paper, an in-flight gas turbine engine bearing prognostic and health management system is presented that integrates information from damage accumulation models and advanced frequency demodulation techniques to achieve robust bearing health state awareness. After successful laboratory rig tests, the system was implemented on a full size gas turbine engine containing a damaged bearing. Data collected while running the engine in a ground test cell was used to verify and validate the performance of the system.