Engine Failure En Route
While en route, the aircraft's engine began to run rough, vibrate, and produce unusual noises. Shortly thereafter, the oil pressure dropped to 0 psi, and the engine seized. The pilot attempted an emergency power-off landing in an open field.
Landing and Nose-Over
During the landing, the nose gear collapsed, causing the nose gear strut to dig into the dirt. The aircraft nosed over onto its back.
Post-Accident Examination
A teardown inspection of the engine revealed that the number three piston pin had failed, resulting in the destruction of a significant portion of the engine's internal components. An examination of the Superior Air Parts piston pin showed that it failed along a fatigue crack that propagated across the longitudinal axis of the pin. The portion of the pin containing the origin of the crack was not recovered, and therefore a determination of the initiating factor could not be made.