Incident Overview
During cruise flight, the pilot observed a loss of oil pressure, accompanied by the smell of burning oil. The propeller subsequently oversped, and the engine quit. The airplane was force landed on a golf course, and collided with trees during the landing roll.
Engine Examination
An examination of the engine revealed that the threads on the oil filter adapter and the mating threads on the engine case were severely fretted, and oil had leaked out of the engine around the adapter threads. There was evidence of oil starvation and thermal distress on internal engine parts.
Maintenance Findings
Evidence suggests that the jam nut which tightens the adapter to the engine case either lost its preload torque, or was undertorqued during maintenance. Logbook entries indicating the last maintenance on the adapter were not located.