What happened
During a night cruise flight, the engine lost power, and the pilot was unable to successfully restore power to the engine. While performing a forced landing, the Cessna (type not specified in source) collided with a berm.
Following this initial event, the engine was disassembled, inspected, reassembled, and underwent a test run for 2 hours and 15 minutes. No mechanical malfunction was observed during this period, and the aircraft was returned to service. However, during a subsequent flight on February 8, 2005, the engine again lost power.
The investigation
An examination of the initial incident revealed that the right main fuel tank was empty. The electric fuel boost pump was found to be operational, and no mechanical defects were identified during the first inspection.
Following the second power loss, a test bench examination of the engine-driven fuel pump was conducted. This investigation revealed excessive fuel leakage from the shaft seal at the drive end of the pump. Further disassembly of the unit showed that the rotor seal at the pump's drive end was worn beyond manufacturer specifications. Additionally, investigators observed wear and damage to the rotor interface with the drive coupling.