Cessna 182 N65903 accident near Toone, Tennessee

Probable cause

A stuck No. 3 cylinder exhaust valve, which resulted in failure of the cylinder's valvetrain components, breach of the cylinder's rocker box cover, and partial loss of engine power due to oil starvation.

NTSB analysis

The private pilot reported that, about 3 hours into a cross-country flight, an instrument panel warning sounded and the oil pressure indicator was in the red arc; however, the engine continued to run smoothly. The pilot began to look for airports or fields to divert to and notified air traffic control of the abnormal engine indication. A few minutes later, the pilot heard "clanging" noises from the engine and it subsequently lost partial power. The engine was not producing enough power for the airplane to fly to the destination airport, and the pilot performed a forced landing in a field. During the forced landing, the airplane sustained substantial damage. Examination of the engine revealed that the No. 3 cylinder exhaust valve had stuck in the closed position, which resulted in failure of the cylinder's valvetrain components, breach of the rocker box cover, and the engine's oil supply being exhausted through the breached rocker box cover. The resulting oil starvation subsequently resulted in a partial loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA17LA019 for the full record.