Casualties unknown

2004-07-20: Cessna P210N (N7736K) — Douglas, WY

Douglas, WY, US

On July 20, 2004, a Cessna P210N (registration N7736K) was involved in an aviation accident near Douglas, WY. Investigators recorded the probable cause as: the failure of the engine's crankshaft due to the rotation of the engine's number two bearing, which resulted in the oil starvation of the crankshaft's number 2 main journal. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During cruise at 22,000 feet, the engine quit. The pilot diverted, but on final approach the left main gear struck a fence post; the airplane landed short, collapsing the gear. Post-accident examination revealed a fractured crankshaft.

Accident Narrative

According to the pilot, while cruising at 22,000 feet mean sea level, the engine ceased operation. The propeller continued to windmill, and the pilot observed approximately 50 gallons of fuel remaining. Attempts to restart the engine were unsuccessful. The pilot declared an emergency and was diverted to a nearby airport.

On final approach to runway 28, the airplane's left main landing gear struck a fence post. The airplane touched down approximately 200 feet short of the runway threshold, causing the left main landing gear to collapse. The airplane then veered left of the runway centerline and came to a stop in the grass. The impact buckled the left wing tip and left horizontal stabilizer.

Examination Findings

An examination of the engine revealed a 7/8-inch by 3/8-inch hole in the top of the crankcase, just forward of the number 1 cylinder. Further examination showed that the engine crankshaft was fractured at the number 2 rod journal. The crankshaft exhibited thermal discoloration and impact marks at the number 2, 3, 4, and 5 rod journals. Rotational scoring and thermal discoloration were observed on the crankshaft's number 2 main bearing. The number 2 bearing was fragmented, and fretting was noted on the crankcase halves at the number 2 bearing through bolts.

Maintenance Records

Engine maintenance records indicated that on November 17, 2003, at 2,845.0 hours, during the airplane's most recent 100-hour inspection, the number 2 cylinder was replaced. At the time of the accident, the total time on the engine was 3,083.0 hours.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20040726X01068. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.