What happened
During a local personal flight under Title 14 CFR Part 91 regulations, a pilot operating a float-equipped airplane experienced a loss of engine power. The incident occurred during the initial climb phase immediately following takeoff from a small lake. Unable to maintain altitude, the pilot performed a forced landing on terrain covered in tundra.
The aircraft sustained structural damage to the fuselage and the right wing as a result of the impact with the ground.
The investigation
An inspection of the aircraft was conducted to determine the cause of the engine power loss. Investigators found that while the gascolator was breached during the accident, the approximately one-half ounce of fuel collected from it was clear, light blue, uncontaminated, and had the appropriate smell for avgas. However, fuel samples taken from the operator's supply tank were light colored and cloudy, showing visible signs of contamination.
Following the accident, the owner had the engine and carburetor disassembled and inspected at a certified aircraft engine repair station. The inspection revealed no mechanical issues that would account for the loss of power. Prior to the accident, the pilot reported no known mechanical anomalies with the aircraft.