NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The pilot reported that both fuel tanks were full when the flight departed. About 30 minutes into the flight, a GPS alarm alerted the pilot to switch fuel tanks, so he switched the fuel tank selector. He then proceeded north to return to the departure airport. About 51 minutes into the flight, while about 2,200 ft above the ground, the engine rpm began to decrease. The pilot attempted to restore power by repositioning the fuel selector, turning on the auxiliary fuel pump, pushing the throttle, and verifying that the mixture control was full rich; however, none of these actions restored engine power. The pilot declared an emergency to the tower air traffic controller, who then provided a vector to a nearby airport. The pilot was unable to visually locate the airport and recognized that he would be unable to land there, so he maneuvered for a forced landing on an expressway. The onboard camera showed the propeller stop while the airplane was on approach and the pilot turn off the fuel selector. The pilot subsequently landed the airplane hard on the expressway, which caused substantial damage to the airplane.
Following recovery of the airplane, 45 gallons of uncontaminated fuel was drained from both fuel tanks; however, fuel system components in the engine compartment contained minimal fuel, consistent with fuel starvation. Although the airplane was equipped with an engine monitor that records and retains engine parameters, it did not record fuel flow. However, the engine monitor did record a sudden and equal decrease in the exhaust gas temperature and cylinder head temperature for all of the cylinders, consistent with the loss of engine power described by the pilot. Although the reason for the loss of engine power was likely due to fuel starvation, the reason for the fuel starvation could not be determined by either an examination of the fuel supply system or a postaccident test run of the engine.