This May 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Cessna 182. Injuries: Serious. Location: Louisville, Ken. Aircraft damage: Substantial.
What reportedly happened: The 200-hour private pilot departed the airport with the intention of completing a cross-country flight. He was about 10 miles from the departure airport when the engine began to run rough. He immediately turned back toward the departure airport. While on final approach, the engine stopped and he executed a forced landing in a residential area.
Examination of the engine revealed that the No. 5 piston failed due to a fatigue fracture. Dark deposits on the fracture indicated that the crack existed prior to the off-airport landing. The origin area was obliterated by post-fracture damage. Review of service difficulty reports for an approximate 10-year period revealed that, given the low incidence of cracking in pistons, it is likely that the cracking was a result of an operational condition, and not a result of a defect in a batch of pistons.
Probable cause: A total fatigue failure of the No. 5 piston during climb.