What happened
The flight was proceeding normally until thirty-five minutes into the journey when the aircraft's engine suddenly lost power. The pilot executed a forced landing in an open field to ensure safety. Upon inspection of the landed airplane, it was observed that the underside of the fuselage was covered with engine oil, indicating a significant leak or venting event.
The investigation
A detailed examination of the engine was conducted at the manufacturer's facility to determine the root cause of the failure. The analysis revealed that a section of the thrust washer from the turbocharger axial bearing had separated from its assembly. This detached component lodged itself within the dual-stage oil pump, causing a mechanical obstruction.
Findings
The lodging of the thrust washer in the pump led to a rapid increase in internal oil pressure. As the pressure exceeded system limits, the engine's oil supply began to vent overboard through the oil breather line. This loss of lubrication and subsequent mechanical failure resulted in the complete loss of engine power during flight.
Safety message
Regular inspection of turbocharger components and adherence to maintenance schedules are critical for preventing catastrophic mechanical failures in pressurized or turbocharged aircraft engines.