This August 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: Cessna 210K. Injuries: None. Location: Show Low, Ariz. Aircraft damage: Substantial.
What reportedly happened: The airplane was in cruise flight when the engine oil pressure dropped to zero, followed four minutes later by a total loss of engine power. The pilot made a forced landing in an open meadow, which resulted in substantial damage to the engine’s firewall.
The post-accident examination revealed that the engine’s crankshaft and connecting rod bearings exhibited lubrication distress and thermal damage, and that the number three crankshaft main bearing exhibited lubrication distress. A gasket located between the STC oil filter adapter and the oil pump housing was displaced and contained dark stains. The STC instructions require that, after the oil filter adapter has been installed, you must re-torque the adapter after 10 hours of operation. An A&P stated that he had re-torqued the oil filter adapter, but could not produce a record of the completed maintenance action.
Probable cause: A total loss of engine power due to the displaced oil filter adapter gasket, which resulted in an oil leak and oil exhaustion.
For more information: NTSB.gov NTSB Identification: WPR09LA422.