On June 20, 1986, a Piper PA-24-250 (registration N6639P) operated by Robert O. Hefner was involved in an aviation accident near West Chester, OH. Investigators recorded the probable cause as: Fatigue cracking of the #6 cylinder leading to in-flight separation and loss of engine power. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During flight, the engine lost power, forcing a road landing that ended with a collision with a road sign. Post-crash examination revealed a fatigue crack in the #6 cylinder.
Accident Overview
During a flight, the engine experienced a loss of power. The pilot was unable to maintain altitude and executed a forced landing on a road. During the landing roll, the aircraft collided with a road sign.
Engine Examination
A post-crash examination of the engine revealed that the #6 cylinder had separated approximately 4 feet above the cylinder flange. A metallurgical examination of the fracture surface identified the presence of a fatigue crack that existed prior to the failure.
Maintenance History
The engine had been overhauled approximately 11 flight hours before the accident. At the time of the overhaul, no fatigue cracking was noted.
Probable cause
Fatigue cracking of the #6 cylinder leading to in-flight separation and loss of engine power.
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