Incident Overview
While en route, approximately 25 miles east of the destination airport, the pilot reported hearing about two seconds of ticking followed by a complete engine failure. The pilot spent 10 to 15 seconds attempting to stop the engine, fearing it would tear itself off the aircraft, before opting for a forced landing in a field.
Landing and Damage
During the approach, the airplane struck a tree, causing one wing to separate. The aircraft then traveled approximately 150 feet before coming to a stop.
Engine Examination
An engine teardown, conducted under FAA supervision, revealed that all four connecting rod caps had separated from their rods. The rod bolt nuts were found lying at the bottom of the oil pan.
Investigation Findings
The investigation determined that a mechanic had installed two modified rod caps without the connecting rod assemblies. The mechanic did not inspect or service the components prior to installation on the engine.