What happened
The pilot was operating a single-engine airplane in cruise flight when the aircraft experienced a propeller runaway and a loss of oil pressure. As the engine began to lose power, the pilot transitioned the aircraft into a glide toward a dirt road.
At 700 feet agl, a connecting rod pierced through the cowling, causing oil to cover the windshield. Because of the obscured vision and uncertainty regarding the condition of the roadway, the pilot chose to perform a landing with the landing gear retracted. The aircraft came to rest upright on the shoulder of the road; the pilot was not injured.
The investigation
An examination of the engine determined that no oil remained in the engine. Investigators found that a 1/4-inch section of the oil filter converter plate gasket was missing and that the gasket was protruding from around the adapter plate.
Records indicated the engine had been factory overhauled and shipped on February 18, 2000, and had accumulated 425 hours since that overhaul. An Airworthiness Directive (AD) existed for engines factory overhauled after April 1, 1999, requiring the replacement of the oil filter converter plate gasket at intervals of 50 hours. Maintenance records revealed that noncompliance with the AD had occurred, as the required gasket replacement had not been performed.