Cessna 172 N734BL accident near Kissimmee, Florida

Probable cause

The pilot's inadequate preflight inspection, which resulted in a total loss of engine power during initial climb due to fuel contamination. Contributing to the accident was a fuel tank cap that did not seal properly.

NTSB analysis

An annual inspection was completed 2 days prior to the accident. Later that evening, the airplane was fueled with 32 gallons of 100 low-lead aviation gasoline. After the refueling a maintenance technician drained a "significant amount" of water from the tanks and the fuel strainer. The next day, the technician informed the pilot about the water he found in the fuel. The pilot sampled fuel from each of the two fuel tank sump drains, but did not observe any water in the samples. He also drained fuel from the fuel strainer, but he did not capture that fuel. The pilot then conducted several takeoffs and landings over a period of about 1/2 hour, and the airplane "ran fine." He parked the airplane, left the airport, and returned the next day for a cross-country flight. During the preflight, the pilot conducted a similar fuel sampling routine, and did not observe any water in the fuel. With the fuel selector valve set to both tanks, the airplane began its takeoff roll and experienced a total loss of engine power during initial climb. The airplane struck a sports goal post during the forced landing on an athletic field that was located approximately 1/4 mile beyond the runway end. Postaccident examination of the airplane revealed several ounces of water in the carburetor, the fuel strainer, and the right fuel tank. After the accident, the pilot told investigators that he "typically" obtained "some water," which he quantified as approximately 1 inch of water in the 3/4 inch-diameter sample container, when he sampled the left fuel tank. The left fuel tank cap was found to have a loose fit, and a 0.028 inch feeler gauge was able to be inserted between the cap gasket and its seat. The airplane had not been flown during the 10 months preceding the day prior to the accident.

Text from the NTSB. Open the NTSB docket for ERA09LA015 for the full record.