Incident Details
During flight at approximately 1,500 feet above ground level, the aircraft experienced a sudden loss of engine power, and the propeller ceased rotating. The pilot attempted an in-flight restart, but the starter motor was unable to turn the propeller. After maneuvering, the pilot executed a forced landing at Van Nuys Airport. The aircraft crash landed between runways 16L and 16R while still in a turn.
Post-Accident Examination
While recovering the aircraft, investigators discovered a hole in the top right side of the engine. A subsequent disassembly and inspection of the engine revealed that the number two connecting rod (part number 642130) had failed. Metallurgical analysis determined that the connecting rod failed due to fatigue, which was caused by partial surface decarburization of the rod material.
Investigation Findings
The fatigue failure of the number two connecting rod was attributed to partial surface decarburization, a condition that weakens the surface layer of metal. The investigation did not identify any other contributing factors. The source of the decarburization was not specified in the available information.