What happened
The day before the accident, the pilot identified an oil leak and requested a mechanical inspection. After a mechanic found no significant indications of a leak, the pilot proceeded to depart for another airport to seek further inspection from a company mechanic.
While en route at 5,000 feet, the pilot detected the smell of oil and observed smoke coming from the engine. Shortly thereafter, an explosion occurred, resulting in a chunk of oil being ejected from the engine and covering the windshield. As the oil pressure gauge continued to decrease, the pilot searched for a suitable location for a forced landing.
The pilot successfully landed the Cessna on a dirt road; however, during the maneuver, the right wing struck a tree, resulting in substantial damage to the wing.
The investigation
An examination of the engine revealed that the crankshaft oil seal was partially dislodged and protruding from the front of the engine case. Records indicated that the most recent condition inspection had been completed two months prior to the accident, with no anomalies noted. The aircraft had flown 43 hours since that inspection.