Incident Overview
A pilot discovered an oil leak the day before a flight and requested a mechanic to inspect the aircraft. The mechanic found no significant indications of a leak, and the pilot decided to proceed to another airport where a company mechanic could perform a more thorough examination of the engine.
Inflight Events
While en route at an altitude of 5,000 feet, the pilot detected the smell of oil and observed smoke emanating from the engine. Shortly thereafter, an "explosion" occurred, and a "chunk of oil" blew out of the engine, covering the windshield. The oil pressure gauge showed a continuous decrease, prompting the pilot to search for a suitable landing area.
Forced Landing and Damage
The pilot executed a forced landing on a dirt road. During the landing rollout, the right wing collided with a tree, resulting in substantial damage to the wing.
Engine Examination
Post-accident inspection of the engine revealed that the engine crankshaft oil seal was partially dislodged and protruding from the front of the engine case. The most recent condition inspection had been completed two months prior to the incident, with no anomalies noted. The aircraft had accumulated 43 flight hours since that inspection.