On April 4, 2004, about 0952 eastern standard time, an unregistered Louis Amato Buccaneer aircraft, operated by a private individual as a Title 14 CFR Part 91 personal flight, crashed in Labelle, Florida. Visual meteorological conditions prevailed, and no flight plan was filed. The pilot received fatal injuries, and the aircraft was destroyed. The flight was originating at the time of the accident. A witness stated that the pilot had just performed maintenance on the aircraft, was conducting a maintenance test flight when the accident occurred. He stated that as he observed the accident aircraft he heard the engine cease operating, and he watched as the pilot initiated a turn to reverse course and land on the runway from whence he had departed. He said that he saw the nose of the aircraft being lowered, but the sink rate increased and the pilot appeared to tighten the turn in an effort to make it back to the field. According to the witness, the aircraft "stalled", and descended, impacting the ground. The witness recalled that the accident aircraft had not been operated for several months. He had observed it parked in an exposed area where it remained stationary, and was subjected to constant sunlight. According to the FAA licensed airframe and powerplant mechanic who examined the accident aircraft's engine, the fuel inside the engine had an odor and exhibited characteristics consistent with automotive fuel that had aged. He said that the fuel had a gel-like viscosity, consistent with aged fuel. The mechanic said that in addition, one of the pistons had seized, and there was evidence that detonation had occurred. The Rotax engine operators manual, for the Rotax 582 engine, installed in the accident aircraft, specifies the requirements for storing of the engine. Some of these requirements include draining of the fuel lines, fuel tanks, and the carburetor float chamber.