Accident Summary
At approximately 2,500 feet shortly after departure, the pilot informed air traffic control of engine problems and a need to return to the airport. Controllers provided a westerly heading toward the airport, but the pilot reported insufficient altitude to reach the destination. The aircraft subsequently impacted terrain in a wooded area about 15 feet west of an open field. A post-crash fire consumed the aircraft fuselage.
Investigation Findings
Examination of the engine revealed that the connecting rod end bushings had not been bored to the proper diameter. This resulted in the connecting rod rubbing against the crankshaft cheek, generating heat stress that caused the crankshaft to fracture. No other mechanical anomalies were reported.
Probable Cause
The probable cause of the accident was that the connecting rod end bushings had not been bored to the proper diameter, leading to heat stress from the connecting rod rubbing against the crankshaft cheek and subsequent crankshaft fracture.