What happened
During the cruise phase of flight, the engine of the aircraft stopped running. Although fuel was available in the system, the pilot was unable to restart the engine. The pilot subsequently performed an emergency wheels-up landing on rough terrain. During the landing sequence, the airplane slid into a tree.
The investigation
An examination of the fuel system was conducted following the accident. Investigators discovered that the fuel pressure regulator had been adjusted to its minimum pressure setting. This adjustment resulted in only approximately 4 psi of fuel pressure being available, whereas a minimum of 10 psi is required for the pressure carburetor to function properly. To verify this finding, investigators blocked the line from the engine-driven fuel pump to the fuel pressure regulator during a test; under these conditions, the fuel pressure increased to over 15 psi. No specific reason was identified for why the regulator had been improperly adjusted.