Flight and Incident
Approximately 40 minutes into the flight and 4 miles south of the destination airport, the airplane was in a normal descent when the propeller increased to maximum RPM. Shortly thereafter, the oil pressure light illuminated, and the pilot noted that the oil pressure gauge indicated zero. The engine subsequently lost power.
Forced Landing
The pilot elected to land in a field about 2 miles south of the runway threshold. During touchdown on soft ground, the landing gear separated from the airplane.
Post-Accident Examination
A post-accident examination of the engine revealed that no oil remained in the engine. The oil filter internal element was collapsed inward. The oil filter converter plate gasket was found separated from the plate and broken in half. Additionally, the oil filter bypass valve was installed improperly. The collapsed oil filter element and blown converter plate gasket are indicative of a cold weather and/or high RPM start. With cold oil, the oil pressure became excessive due to the faulty bypass valve, resulting in the collapse of the filter and failure of the oil filter converter plate gasket.