ERA09LA516 · SIAI-Marchetti F.260

According to the pilot, the preflight, engine run-up, taxi, and takeoff from runway 9 were all normal. At 500 feet above ground level (agl) the engine lost power and the pilot maneuvered the airplane for a downwind landing on runway 27. The pilot confirmed the positions of the throttle, propeller, fuel pump, and fuel selector controls and the engine regained power temporarily. About 300 feet agl, the engine again lost power and the pilot elected to land in an off-airport field with the gear up due to the extension time required for the airplane’s landing gear system. During a postaccident examination of the airplane by a Federal Aviation Administration (FAA) inspector, operation of the airframe boost pumps revealed that the pumps would not draw fuel. Closer examination of the fuel selector valve and fuel shut-off cock revealed staining consistent with fuel leakage. When positive pressure was applied to the fuel tanks, fuel leaked around the shaft of the fuel shut-off cock located under the cockpit instrument panel area. Pressure was removed from the tanks, the fuel shut-off cock was sealed with a rag, and the boost pumps were then able to draw fuel when power was applied. Removal of the rag created an air leak, and the boost pumps would not draw fuel. The fuel selector valve and the fuel shut-off cock were then removed, disassembled, and examined under the supervision of the FAA inspector. Examination revealed that the interior O-ring seals for the selector shafts were loose on both. Another owner of the same make and model airplane provided a written account of a nearly identical scenario, which was resolved with the replacement of the O-ring seals. The manufacturer's Special Inspection List outlined "overhaul/replacement" of the fuel shut-off cock every 5 years or 1,500 flight hours, whichever occurred first. At the time of the accident, the airplane had accrued 1,592 total aircraft hours. Seven months, and 8 aircraft hours had elapsed since the airplane's most recent annual inspection. According to the FAA inspector, 14 CFR Part 43, Appendix D, listed the minimum inspection requirements for the completion of an annual inspection, that manufacturer's recommended overhaul schedules were recommended and not mandatory, and that the overall responsibility for the airworthiness of the airplane fell to the owner/operator.

Verbatim NTSB analysis and probable cause from the NTSB dataset