Background
The accident involved an experimental amateur-built Adams DA1, registration N797A, serial number 01. The aircraft was constructed from a Sonerai homebuilt airplane kit and was powered by a converted Volkswagen 75-horsepower automobile engine equipped with a Sterba wood propeller. It had a fixed tricycle landing gear configuration, which was a recent modification from a tailwheel setup. The fuselage was steel tube with fabric covering, and the wings were aluminum.
Flight History
On March 2, 2015, at about 1150 eastern standard time, the aircraft departed from Sebring Regional Airport (SEF), Sebring, Florida, for a personal flight under 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The pilot owned the aircraft and had built it. Approximately two years earlier, the same airplane experienced a loss of engine power just after takeoff due to a clogged fuel filter, resulting in a propeller strike during a landing back on the runway. The accident flight was the first since that incident, during which the fuel filter had been replaced and the landing gear converted from tailwheel to tricycle.
Witness Observations
Near the accident site, witnesses reported hearing a "spitting and sputtering" engine sound as they observed the airplane descending from low altitude. The pilot managed to land on grass about one mile south of SEF. After touchdown, a postcrash fire erupted and destroyed the cockpit before the pilot could exit.
Wreckage and Impact
The airplane touched down on grass and slid approximately 75 feet on a magnetic heading of about 070 degrees before coming to rest upright adjacent to a canal behind a residence. Ground scar evidence included fragments of the right aileron, nose landing gear, and wooden propeller. The fuel tank, located aft of the engine firewall and forward of the cockpit, was compromised during the landing. A postcrash fire consumed the cockpit, propeller, and all fuselage fabric covering forward of the undamaged empennage. The right wing sustained impact damage at its tip and forward outboard leading edge, and its inboard trailing edge was diagonally deformed about one foot. The inboard four feet of the left wing was consumed to the spar, and most of that wing was fire damaged. Flight control continuity was confirmed from the cockpit to the rudder and elevator; the left and right aileron connections were displaced consistent with impact damage. The entire fuel system—including the tank, carburetor, and fuel filter—was consumed by fire.
Engine Examination
The engine was fire damaged and could not be rotated. Subsequent disassembly at Sebring Regional Airport, including examination of all cylinders, pistons, rocker arms, valves, and spark plugs, revealed no evidence of preimpact mechanical malfunctions.
Medical and Toxicological Findings
An autopsy performed by the Office of the District 10 Medical Examiner identified hypertensive and atherosclerotic heart disease and stated the cause of death as the postcrash fire. Toxicological testing by the FAA Bioaeronautical Science Research Laboratory detected several substances in the pilot's system: citalopram and its metabolite, desloratadine, ephedrine (in urine only), loratadine, pseudoephedrine, and tamsulosin. No probable cause was determined by the investigation.