Background
The pilot was conducting a test flight following the completion of an annual inspection of the airplane. The flight originated from Merrill Field.
In-Flight Incident
During the flight, an oil film began to appear on the windshield. Noticing this, the pilot initiated a return to Merrill Field. However, before reaching the airport, the oil film on the windshield intensified, and the oil pressure gauge showed a decline. Faced with deteriorating conditions, the pilot decided to land at a private airstrip instead.
Landing Sequence
On approach to the private airstrip, the pilot performed a sideslip maneuver to maintain visibility through the oil-covered windshield. He reported a normal touchdown. However, during the landing roll, the airplane veered to the left. It subsequently collided with a rock and tall vegetation, causing the airplane to nose over.
Post-Accident Inspection
A subsequent examination of the airplane identified a small leak in the engine oil cooler.