ERA15LA265

The flight instructor reported that, during the initial climb for the local, instructional flight with the student pilot/owner at the controls, the engine began to lose power. The flight instructor assumed the controls and attempted a forced landing on a road in a residential area. During the forced landing, the left wing struck a tree, and the airplane then came to rest upright, which resulted in structural damage to the airframe. During postaccident examination, dark, granular sediment was found inside the fuel tank, and it was of sufficient quantity to interrupt fuel flow to the engine. The airplane had been stored outside; it could not be determined how, or when, the granular contamination was introduced into the fuel tank. An examination of the engine and fuel system revealed evidence of some leakage around the carburetor, and the cylinders around the exhaust valves showed signatures consistent with operation at high exhaust gas temperatures. Examination of the fuel tank revealed that it contained automotive gasoline (auto gas). The student pilot believed that the use of auto gas was permitted; however, no supplemental type certificate (STC) for the use of auto gas existed, and the airplane was not placarded for auto gas use. The auto gas also might have contained ethanol, which was not permitted with or without an STC for auto gas use.

On July 11, 2015, about 0815 eastern daylight time, a Luscombe 8A, N28864, force landed following a partial loss of engine power during the initial climb from Mid Florida Air Service Airport (X55), Mount Dora, Florida. The student pilot and flight instructor were not injured, and the airplane was substantially damaged. The airplane was operated by the student pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as an instructional flight. Day, visual meteorological conditions prevailed, and no flight plan was filed. The flight was originating at the time of the accident.According to the flight instructor, all pre-departure operations were "normal." The student pilot sumped the fuel gascolator and no contamination or water was observed. The student pilot, who was also the airplane's owner, initiated the takeoff roll. The engine initially developed power normally and ran smoothly. About 150 feet above the ground, during the initial climb, the engine began to lose power. The instructor took control of the airplane and executed a left turn toward a road in a residential area. During the forced landing attempt, the left wing impacted trees prior to touchdown and the airplane came to rest upright. A Federal Aviation Administration (FAA) inspector responded to the accident site and examined the wreckage. The fuselage exhibited structural damage from impact forces. The left wing was sheared off about three feet from the wing tip, and the left wing spar was broken at the wing strut attachment point. The rear fuselage was buckled between aft cabin wall and the empennage. The wreckage was moved to a hangar for a more detailed inspection. On July 13, 2015, the engine and fuel system were examined by an FAA airworthiness inspector. The fuel tank contained automotive gasoline (auto gas) with a "strong smell of ethanol." There were no placards on the aircraft, nor maintenance entries in the airframe logbooks, permitting the use of auto gas. The fuel tank was drained and the liquid was yellow in color and contained black, granular sediment. There was red/orange discoloration on all cylinders in the areas of the exhaust valves, indicative of operation at high exhaust gas temperatures. The carburetor body and seals were wet with fuel. The fuel primer was in the "on" position. The lower engine cowling had fuel staining signatures near the area of the carburetor and trailing in the aft direction. "Minor corrosion" was found inside the fuel gascolator bowl. According to the maintenance logbooks, an annual inspection of the airframe and engine was completed on June 22, 2015. According to the FAA, the airplane was stored outside, and no determination could be made as to how, or when, the granular contamination was introduced into the fuel tank. According to the airworthiness inspector and FAA Special Airworthiness Information Bulletin CE-07-06, dated October 27, 2006, ethanol is not permitted for aircraft with or without a Supplemental TypeCertificate (STC) for auto gas use. The FAA coordinator reported that the aircraft owner, who was also the student pilot, was under the impression that auto gas could be used in his airplane. The coordinator confirmed that no STC existed for the accident airplane to use auto gas. She also stated that the amount of contamination in the fuel tank was sufficient to interrupt fuel flow to the engine.