Engine Failure and Forced Landing
During a flight, the pilot observed that the engine's revolutions per minute (RPM) had dropped from 2500 to 2000. Despite attempts, the pilot was unable to restore the RPM. Subsequently, the pilot heard a loud noise emanating from the engine compartment, and the engine seized. The aircraft then performed an emergency landing in a corn field, during which the aircraft sustained damage.
Examination Findings
A teardown inspection of the engine was conducted to determine the cause of the failure. The inspection revealed that the number 3 connecting rod, part number 74502-S, was broken, bent, and wedged between the number 4 connecting rod and the engine case. The number 3 bearing surface on the crankshaft was galled. Both rod bolts on the number 3 connecting rod were broken. Additionally, the number 2 and number 4 connecting rod bearings, part number 72218, had spun. Metal particles were found throughout the engine. The oil quantity in the engine was measured at 5 1/2 quarts.