Beech P35 N112MB accident near Westerly, Rhode Island

Probable cause

A total loss of engine power due to inadequate maintenance of the oil filter adapter, which resulted in an oil leak and subsequent oil starvation to the engine.

NTSB analysis

During cruise flight over open water, the airplane experienced a total loss of engine power, and the private pilot ditched the airplane. Subsequent examination of the engine revealed that the oil filter adapter was loose and the fiber gasket was torn and partially extruded. Because of these conditions, oil leaked from the engine, which led to the failure of the Nos. 2 and 4 connecting rods due to a lack of oil lubrication. The oil filter adapter was not original equipment on the engine; it was installed under a supplemental type certificate which required that the oil filter adapter fiber gasket be replaced anytime the oil filter adapter was removed from the engine and reinstalled and every 300 hours or 3 years, whichever occurred first. Maintenance records indicated that the oil filter adapter was installed about 4 1/2 years before the accident. No other maintenance entries or records pertaining to the inspection of the fiber gasket was noted during the 4 years before the accident, and no record concerning the installation of a new oil filter adapter fiber gasket was located.

Text from the NTSB. Open the NTSB docket for ERA16LA217 for the full record.