Background
According to the pilot, the main fuel tanks had been filled and the two auxiliary tanks were nearly full earlier. The pilot had flown for approximately one hour using one of the auxiliary tanks for cruise fuel.
Accident Sequence
During the subsequent flight, the pilot took off using the main fuel tanks. After leveling at an altitude of 2,600 feet, the pilot switched the fuel selector to one of the auxiliary tanks. Moments later, the engine ceased operation, and the pilot was unable to restart it. A forced landing was executed into the treetops, and the aircraft subsequently crashed to the ground.
Examination
Each auxiliary tank holds about 17 gallons, and the aircraft's fuel consumption rate is 13 to 15 gallons per hour. The pilot stated that he may have inadvertently switched to a nearly depleted auxiliary tank, which could have been the reason for the engine failure. An examination of the fuel system revealed that the main fuel filter, selector, and spider assembly were dry. No other evidence of any preimpact malfunction or failure of any airframe or engine components was found.
Probable Cause
The pilot inadvertently switched to a nearly depleted auxiliary tank, resulting in fuel starvation and engine failure.