What happened
During the initial takeoff climb, witnesses observed the engine of the aircraft sputter and lose power. The nose of the airplane leveled out as the engine briefly restarted before losing power again. Following this loss of power, the aircraft entered a steep left bank, estimated to be between 45 and 100 degrees. The nose subsequently pitched down, and although witnesses saw the aircraft level out momentarily, it collided with the ground.
The pilot had conducted three sightseeing flights, each lasting approximately 10 to 15 minutes, without shutting down the engine between them. There was no record of the aircraft being refueled prior to these flights. A passenger on the first flight noted that one fuel gauge was in the yellow range, while a passenger on the second flight reported that the left fuel gauge indicated empty and the right tank was less than a quarter full.
The investigation
An examination of the aircraft revealed no evidence of mechanical failure or malfunction regarding the airframe, engine assembly, accessories, or flight controls. Although the left and right main fuel tanks were ruptured, there was no evidence of fuel presence or browning of vegetation at the crash site.
Findings
Investigation into the fuel state noted that a friend of the pilot believed the left main fuel gauge indicated empty while the right was half full the previous day. The aircraft's total fuel capacity is 40 gallons, with three gallons of unusable fuel in each main tank. According to the Pilot's Operating Handbook, takeoff should not be attempted if fuel quantity gauges are in the yellow band or if there is less than 13 gallons remaining in each main tank.