This July 2009 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: Kitfox IV. Injuries: 1 Minor. Location: Escondido, Calif. Aircraft damage: Substantial.
What reportedly happened: During cruise flight the pilot noticed oil trailing down the landing gear strut. The engine gauges indicated a normal oil pressure. The pilot altered course to head for an airstrip to make an emergency landing, but when the oil pressure remained constant, the pilot decided to pass up the airstrip and continue to his destination. Shortly thereafter, the oil pressure dropped to zero, and the engine lost power. The pilot performed a forced landing. During the landing roll out, the airplane struck a ditch and nosed over.
Inspection of the engine revealed that the number four cylinder exhaust pushrod O-ring seal had failed, which allowed the oil to leak out the engine, causing the engine to seize. The pilot stated that he had removed the cylinder head two years prior to the accident, and reused the exhaust pushrod O-ring seal. According to the engine manufacturer’s maintenance manual recommendations, all sealing rings, gaskets, securing elements, O-rings and oil seals are to be replaced at engine reassembly.
Probable cause: A total loss of power due to an oil exhaustion-induced seizure of the engine. The pilot’s decision to continue flight to the original destination after becoming aware of the in-flight oil leak instead of landing at an intermediate airport to investigate the source and extent of the problem is also causal. Contributing to the accident was the pilot’s reuse of the pushrod oil seal during maintenance in contradiction to the engine manufacturer’s maintenance instructions.
For more information: NTSB.gov NTSB Identification: WPR09LA369
