Preflight and Fuel Status
During preflight inspection, the student pilot observed over 20 gallons of automotive fuel in the left tank and 5.5 gallons in the right tank. The aircraft had been modified under an FAA supplemental type certificate to operate on automotive fuel.
Fuel Selector Uncertainty
The pilot stated that the fuel selector was in the right tank position when he entered the aircraft. He believed he switched it to the left tank before departure but was not certain of this action.
Engine Power Interruptions
Immediately after lift-off, the pilot experienced intermittent power interruptions. The interruptions became more pronounced while flying the right-hand traffic pattern. When the pilot turned base, the engine stopped completely. The pilot did not recall attempting to switch fuel tanks during the event.
Forced Landing
The aircraft landed approximately 300 yards short of the runway and struck a ditch.
Post-Accident Findings
Following the accident, two tablespoons of automotive fuel were found in the carburetor float bowl. The engine was later successfully test-run. An individual who entered the aircraft after the accident shut off the fuel selector valve; that person reported switching the valve from a position clockwise to the right to OFF.
Maintenance History
The last documented annual inspection of the aircraft occurred in 1993.