Failure analysis of an un-cooled turbine blade in an aero gas turbine engine

Failure of an un-cooled turbine blade in an aero gas turbine engine is analyzed to determine its root cause. The operational condition of the engine was studied and metallurgical investigations are carried out on the fractured blade. The failure has originated from the leading edge and has propagated towards the trailing edge. Thermal cracks due to surface oxidation leading to fatigue were found to be the cause of the blade failure. Operation at elevated temperatures due to malfunction of sensors in the engine control system was found responsible for initiating the thermal cracks.