Metallurgical investigation of a gas turbine separated shaft resulting in an in-flight engine shutdown

An uncommanded in-flight shutdown occurred during the climb phase of a commercial flight. The incident was attributed to an engine stall and subsequent flameout, preceded by an exhaust gas temperature exceedance. A subsequent teardown inspection revealed that the high-pressure turbine rotor had shifted, and further examination showed separation of the high-pressure turbine shaft. The engine and shaft had recently undergone maintenance and had accumulated a significant number of cycles since new. The presentation covers the metallurgical findings and the likely root cause.