On June 16, 1996, a Cessna 177RG (registration N2186Q) was involved in an aviation accident near Lake Placid, FL. Investigators recorded the probable cause as: maintenance personnel's failure to properly torque the cylinder installation bolts. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot reported a cylinder separation and engine fire, shut down the engine, and made a forced landing in a pasture, colliding with two fences. Investigation found crankcase fretting typical of torque loss.
Incident Overview
Approximately one hour after departure, the pilot informed the air traffic controller that the number 2 cylinder had separated from the engine, accompanied by an engine fire. The pilot requested radar vectors to the nearest airport. The controller cleared the flight to an airport located 12 nautical miles north. The pilot shut down the affected engine, and the fire extinguished. Subsequently, the pilot executed a forced landing in a pasture short of the airport. During the landing roll, the airplane struck two fences.
Engine Examination
An examination of the engine after the incident revealed severe fretting on the crankcase parting surfaces at the number two bearing saddle and dowels. According to the examination, the surface fretting observed in the crankcase is typical of conditions associated with a loss of torque on the mating surfaces.
Previous Maintenance
The operator reported that the engine had been overhauled 291 flight hours prior to this flight.