Incident Overview
During a cross-country flight, the aircraft's engine experienced a sudden power loss, popping and quitting completely. The pilot identified a road for landing but observed a vehicle on approach, prompting a diversion to a field. Upon touchdown, the nose gear collapsed.
Post-Accident Investigation
Examination of the engine revealed a broken crankshaft that had failed at the number 4 bearing journal cheek. The crankshaft exhibited multiple gouges extending through approximately 90 degrees of its circumference. The fatigue initiation area appeared to be located within one of these gouges.
Maintenance History
Review of the engine's maintenance records showed numerous cylinder replacements over its service life. However, no logbook entry indicated a previous sudden stoppage of the engine.