Forced Landing After Engine Power Loss Due to Fuel Contamination (N2450V)

Incident Overview and Sequence of Events A pilot departed on a flight from one airstrip to another. After completing one landing and takeoff, the pilot returned to the departure airstrip and performed a simulated forced landing. Following the landing, the pilot back taxied and departed to the north. At 250 feet above ground level, the engine lost power. The pilot switched from the right to the left fuel tank and primed the engine. The engine surged briefly and quit again, prompting the pilot to perform a forced landing to a swampy area. ## Investigation Findings The investigation revealed 6 gallons of aviation 100LL fuel in the left tank and 3.5 gallons of automotive fuel in the right tank. The engine was test run on the airplane and operated normally. The airplane was equipped with a 12.5-gallon fuel tank in each wing, and the operations manual stated not to take off on less than a quarter tank.