Accident Overview
An airplane experienced a loss of engine power while returning from a fire patrol flight. The pilot executed a forced landing in a field. Upon touching down, the aircraft ran into soft dirt and nosed over.
Post-Crash Examination
A post-crash examination of the aircraft revealed no evidence of fuel remaining in the fuel system. The examination also found that the left tank fuel cap gasket was missing, and a large fuel stain existed in the area of the left tank filler opening.
Pilot Report
According to the pilot, he departed with full fuel tanks, which he had visually confirmed. He initially operated on the left tank for 1.5 hours, then switched to the right tank for 2.1 hours. When the right tank ran dry, he switched back to the left tank, but the engine did not regain power. The pilot noted that after prior patrol flights lasting approximately 3.5 hours, the aircraft would have 5-6 gallons of fuel remaining. He normally estimated remaining fuel using the known average consumption rate of the engine and elapsed time, rather than relying on fuel gauge indications, which he said were not “that accurate.”