What happened
The aircraft experienced a total loss of engine power during flight. This failure was directly attributed to the presence of water within the fuel system. Following the incident, an inspection of the airframe revealed that water had accumulated in the carburetor assembly.
Prior to the flight where the failure occurred, the pilot had performed routine fuel drain procedures. The pilot reported draining between 4 and 5 gallons of fuel from each wing tank during the month leading up to the accident, with no water detected at that time. Immediately before the flight in question, additional drains were performed on both the engine drain and the wing tank drains, again revealing no water contamination.
The investigation
Post-accident examination of the aircraft identified water contamination as the root cause of the power failure. Investigators found significant amounts of water within the carburetor assembly after the event. This finding stands in contrast to the pilot's pre-flight checks, which had not detected any moisture in the fuel system immediately prior to the flight.
Findings
The investigation concluded that water contamination in the fuel was responsible for the total power loss. The presence of water in the carburetor assembly prevented proper engine operation. Despite the pilot's diligent fuel drain procedures in the preceding month and immediately before the flight, water had managed to accumulate in the system, leading to the failure.