Causes of fatigue failure in the main bearing of an aero-engine

Abstract Fatigue failure in the central main bearing (CMB) of the compressor shaft of an aero-engine resulted in an air-crash. The cage of the CMB broke due to fatigue, got stuck between the bearing balls and the outer race, misaligned them resulting in severe wear of the components and damaged the function of the engine. Simulated laboratory tests are conducted and the source of cyclic stresses is discussed.