Accident Description
The pilot reported that the aircraft was en route over low rolling foothills when the engine quit. The aircraft's firewall and nose gear were damaged during the forced landing on a road.
Fuel Examination
After the accident, an A&P mechanic examined the aircraft and found the fuel system intact. Only residual fuel was present in the fuel tanks. Following recovery, the engine was started using the airframe systems and accelerated to power smoothly, with normal magneto drops observed.
Pilot's Fuel Management
The pilot stated that the aircraft is rented with full fuel by the FBO. During the preflight inspection, she placed her fingers in the filler port and felt fuel at a level about one inch below the top of the filler neck. The pilot noted that the fuel gauges in this aircraft historically read something less than full when the tanks are filled, and the gauge reading at start between 3/4 and full seemed normal.
Operational Details
Cessna Aircraft reported that the tanks must be filled to the top of the filler neck to obtain a 20-gallon usable fuel level. A fuel level at the bottom of the filler neck equals 18 usable gallons, and each inch in fuel level below that is equal to about 2 gallons of fuel. According to FAA ATC communication tapes, the difference between takeoff time and the accident was 3 hours 22 minutes. The Safety Board calculated the expected fuel usage using both the aircraft performance charts in the Cessna Pilot's Operating Handbook and specific fuel flow figures provided by Lycoming for an engine operated at full rich condition. With allowances for engine start, taxi, and takeoff, the Safety Board calculated that 28.4 gallons of fuel would be used when the engine was leaned and the aircraft flown according to the manual. In the full rich condition, 33.4 gallons of fuel would be required.