Accident Sequence
The airplane was fueled the night before the accident and confirmed full during a preflight the morning of the accident. Subsequently, a company pilot (not the accident pilot) flew 10 sightseeing flights with the mixture set to full rich. Fuel quantity gauges indicated decreasing fuel during these flights; during the last flight, the gauges indicated more than half and less than quarter full, respectively. The accident pilot relieved the pilot who had flown the 10 flights; at that time, the airplane had been operated for 3.75 hours since fueling.
The accident pilot reported visually checking the fuel tanks, though all adult passengers stated he did not. The flight departed. At 200 feet msl, the pilot later stated that the engine quit when he reduced power to 25 inches of manifold pressure. He maneuvered for a forced landing in a field, touching down with full flaps at an indicated airspeed of 80 knots. Upon touchdown, the nose landing gear separated from the airplane, and the airplane collided with a 6-8 feet high sand dune. The airplane came to rest inverted on top of the sand dune.
Fuel Examination
Examination of the fuel lines at the fuel selector valve, at each reservoir fuel tank, and at the fuel control unit revealed no fuel. No fuel was found in the auxiliary fuel pump, engine driven fuel pump, or reservoir tanks. The fuel selector was found positioned to the right fuel tank, which was calculated to contain 7 gallons of fuel; the unusable amount of fuel in that tank is 3.5 gallons.
The engine was placed on a test stand; impact-damaged components were replaced or repaired, and the engine was started and found to operate normally with no discrepancies noted. Testing of the fuel gauges revealed they were operative, but testing of the fuel transmitters revealed several discrepancies.
Fuel Consumption and Procedures
The average fuel consumption over a 9-day period was 15.14 gallons per hour. The airplane had been operated for 3.79 hours since fueling at the time of the accident. The operator had a procedure requiring the pilot to dip the tanks during preflight and the chief pilot to randomly dip the tanks during the day. The accident pilot did not dip the tank before the flight, and the chief pilot did not randomly dip the tanks throughout the day. The dipstick used was a wooden paint stirrer with only a "full" mark annotated; no graduate marks beneath the full mark were noted.
Maintenance History
The Service Manual indicates that the fuel quantity indicators and transmitters require checking every 50 hours and also during a complete inspection of the airplane. The airplane was last inspected on May 11, 2001, using an approved checklist that consisted of the inspection chart found in the Service Manual. The airplane had accumulated 48 hours since that inspection at the time of the accident.