Incident Overview
During cruise flight at 10,500 feet with the engine set at 28 inches of manifold pressure and 2,350 RPM, the engine suddenly lost power and began knocking. The pilot observed a rapid drop in oil pressure and noticed a three-inch hole in the top of the engine cowling.
Forced Landing Attempt
The pilot attempted to land on a highway but was unable due to vehicular traffic. He then changed his approach to land beside the roadway. Just before landing, he saw power lines and pulled up to avoid a collision. The aircraft then entered a high sink rate and stalled. The pilot stated that the aircraft impacted the ground in a flat, rather nose-low attitude.
Post-Impact
Immediately after impact, the aircraft began burning, but the pilot exited the plane without injury.
Engine Examination
A teardown of the engine revealed a catastrophic failure of the number two piston and wrist pin. However, the investigation did not determine which component failed first. The engine had been overhauled on June 5, 1984, using several components, including pistons and piston pins, manufactured by Superior Air Parts, Inc. According to maintenance logs, the aircraft had flown 1,045 hours since the major overhaul of the engine.