Incident Description
The pilot was in cruise flight at 2,000 feet above ground level when the engine did not appear to be producing full power. The pilot reversed course toward the departure airport. Subsequently, the engine oil pressure decreased to zero and the engine lost power. The pilot executed an emergency landing to non-suitable terrain, and the airplane sustained substantial damage during the landing roll-out.
Engine Examination
The engine was disassembled after the incident. The No.1 cylinder was removed, revealing that the No.1 connecting rod was bent and had separated from the crankshaft journal. The No.1 connecting rod, piston, and oil suction debris were forwarded to the NTSB Materials Laboratory for further examination.
NTSB Findings
The examination conducted at the NTSB Materials Laboratory revealed a failure of the No.1 connecting rod bearing.