This September 2010 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: Navion G. Injuries: 1 Minor. Location: Dublin, Ga. Aircraft damage: Substatial.
What reportedly happened: The airplane was in cruise flight at 7,000 feet MSL when the engine began to run rough and the oil pressure decreased. The pilot performed a forced landing in a field. During the roll out, the airplane hit a ditch.
Initial examination of the engine revealed that the oil drain tube remained attached to the oil quick-release drain plug, and oil was leaking down the side of the oil drain tube, likely as a result of the quick-release oil drain plug not being properly secured. The pilot had recently changed the engine oil himself. A subsequent teardown examination of the engine revealed that the No. 5 connecting rod failed due to lack of lubrication.
Probable cause: The pilot’s failure to properly secure the oil drain plug after changing the engine oil, which resulted in oil starvation and an engine failure during cruise flight.
For more information: NTSB.gov. NTSB Identification: ERA10LA487