Incident
During a night flight, oil began spreading across the windshield and heavy smoke entered the cockpit through the cabin heater. The pilot opened the cabin windows, reduced power, and turned back toward the airport. The oil pressure dropped to 5 psi. The pilot descended to land on a road that was visible on the moonlit night. As the aircraft neared the ground, the engine reportedly began to rattle. The pilot lined up with the road but momentarily lost sight of it due to clouds obscuring the moon. Just before landing, the pilot saw a guy wire and maneuvered to avoid a collision. The aircraft stalled and hit a ditch, causing the nose and left main landing gear to shear off. The aircraft continued through bushes, hit a fence, and nosed over.
Investigation
An investigation revealed that two oil lines had rubbed together until one had worn through. The oil lines should have been protected by a rubber spacer and a clamp. Either the clamp had failed or had not been installed. Subsequently, the rubber spacer had moved and allowed the lines to rub together.