What happened
Prior to departure, the pilot performed several preflight tasks, including cleaning the Cessna (type not specified, but context implies light aircraft) and checking the oil capacity, which was found to be 7 quarts. The pilot checked the right wing fuel tank for contaminants and added 5 gallons of 100 low lead fuel after finding the tank half full. However, the pilot did not check the fuel tank for contaminants after this refueling. During the preflight, the pilot failed to check the gascolator because he was unaware the aircraft was equipped with one.
After starting the engine via hand propping, the pilot ran the engine for several minutes before shutting it down due to a lack of indication on the ammeter. This issue was attributed to the alternator and likely caused by the aircraft sitting for four months. The pilot then proceeded to taxi the aircraft on the water, performing idle taxiing and step taxis across the lake. After checking the magnetos and carburetor heat at 1,800 rpm with no discrepancies noted, the pilot attempted takeoff.
At an altitude of approximately 200 to 300 feet, the engine quit. Due to a lack of electrical power, the pilot could not attempt a restart. After pumping the throttle without success, and finding insufficient lake surface ahead, the pilot initiated a 180-degree turn. During the maneuver, the aircraft stalled approximately 10 to 20 feet above the water with a slight right wing low attitude. The aircraft impacted the water on the right wing, causing damage to the wing.
The investigation
An FAA airworthiness inspector examined the recovered aircraft and found that the gascolator was approximately 1/2 full of water. While the carburetor bowl was not examined, the engine was removed and placed on a test stand, where it was found to operate normally. Witnesses reported hearing the engine sputter or run roughly after takeoff before it ceased functioning. Post-accident fuel samples from the fuel nozzle and fuel filter showed no contaminants, and a check of the fuel supply tank with water-finding paste was negative.