What happened
On July 15, 2006, at approximately 08:05 UTC, a Bell 206L helicopter was conducting a commercial charter flight near Maria Lankowitz, Austria. The aircraft was flying at an altitude of approximately 4,300 feet MSL (1,500 feet AGL) when it experienced a sudden engine failure accompanied by an engine fire.
The pilot immediately initiated an autorotation procedure. The helicopter performed an autorotative landing on a sloping meadow. Due to the low rotor RPM and the downward slope of the terrain at the time of touchdown, the tailboom was severed between the stabilizer fins by an impact from a main rotor blade.
There were no fatalities and no injuries among the three passengers and two flight assistants on board. All occupants were successfully evacuated. The pilot managed to extinguish the engine fire using an onboard cabin fire extinguisher. The aircraft sustained substantial damage.
The investigation
The Austrian SUB investigation included a technical examination of the engine components, involving experts from MTU Aero Engines. The investigation focused on the condition of the turbine wheels and the operational history of the engine. Investigators examined the turbine stage 3 components, specifically turbine wheel #3 (P/N 23065833), to determine the origin of the failure. The analysis also reviewed maintenance records and engine operating parameters.