Primary finding
Probable cause
The failure of the engine exhaust valve which resulted in the loss of engine power. The soft terrain in the landing area was a factor.
Investigator assessment
Analysis narrative
The pilot reported a loss of engine power during an aerial patrol flight. He attempted an off airport landing in a field. The aircraft nose gear sheared off in the soft terrain and the aircraft nosed over. Examination of the engine revealed that the number one exhaust valve had failed, resulting in the loss of engine power.
Source record
Factual narrative
On September 9, 1993, about 1530 eastern daylight time a Cessna 172, N2347E, collapsed the nose landing gear during a forced landing near North Myrtle Beach, South Carolina. The airplane was operated by Bentco Aerial Patrol under 14 CFR Part 91 and visual flight rules. Visual meteorological conditions prevailed. A flight plan was not filed for the power line patrol flight. The commercial pilot was not injured and the airplane was substantially damaged. Origination of the flight was Athens, Georgia, about 1400 on the same day. The pilot reported that the engine lost power. A forced landing was made in a field. During the landing roll, the nose gear collapsed and the airplane nosed over. Examination of the aircraft engine revealed that the number one exhaust valve had failed. The valve head was found in the engine crankcase, and there was metal contamination found in the valve cover of the number one cylinder. The aircraft owner failed to respond to the request for completion of NTSB Form 6120.1/2, Pilot/Operator Aircraft Accident Report.(See Attached letter of Request and Receipt for Certified Document.) -