What happened
Approximately 20 minutes after takeoff, the Cessna engine began to shake violently. The pilot attempted to manage the situation by reducing the throttle to 15 inches of manifold pressure and decreasing the RPM to 2300. During this period, white smoke emerged from the top of the cowling, with a small amount entering the cockpit, and a large volume of black oil was discharged from the front of the engine cowling.
The pilot turned the aircraft toward the nearest airport, but the engine ceased operation completely about two minutes later. To avoid overtaking vehicles on the highway during the final approach, the pilot elected to deviate to the side of the road for the landing. During the landing roll, the nose gear was torn off. The pilot was not injured.
The investigation
Upon securing the aircraft, the pilot discovered two large holes in the top, aft portion of the engine casing, along with pieces of casing and a piston scattered on and around the engine. A piston rod was found resting on top of the engine, and a third hole was identified at the bottom of the engine casing.
Disassembly of the engine revealed that the number 2 cylinder main bearing had rotated, which closed off the oil supply to the bearing. The engine had operated for 1464.5 hours since its last overhaul, whereas the manufacturer's recommended time between overhauls is 1,600 operating hours. Additionally, an oil analysis performed on December 7, 2001, had indicated that wear metals were high for the amount of oil time elapsed.