What happened
A pilot flew a float plane to Cottonwood Lake for maintenance purposes. During the maintenance, a quick drain was installed in one wing tank, and the other wing tank was drained. Although the mechanic informed the pilot of the low fuel condition, the pilot believed there was enough fuel to complete the flight to Wasilla Lake, located approximately 3 miles west of Cottonwood Lake.
The pilot did not visually inspect the tanks prior to departure. Shortly after takeoff, the engine lost power. The pilot attempted to turn back toward Cottonwood Lake to perform a landing, but the aircraft lacked sufficient altitude. While attempting to turn away from a house, the aircraft stalled and crashed into trees. No injuries were reported.
The investigation
Post-accident investigation of the fuel levels revealed that less than one gallon of fuel remained in one tank, while the other tank contained approximately one quart of fuel. According to the aircraft's owner's manual, the unusable fuel amount is 1.5 gallons during maneuvering flight and 1 gallon during level flight.