OKLAHOMA CITY, OK, USA
N86S
SEMPLE SMYTH SIDEWINDER
The pilot had just purchased the airplane and was planning to return to his home in Tulsa, Oklahoma. He and the seller flew the airplane on an 'orientation ride' for 'approximately 10 minutes' before the pilot departed. According to the seller, the pilot had considerable experience in a similar airplane, but the fuel selector handles in the two airplanes were configured in an opposite manner. The accident airplane was observed to depart from runway 17 and turn east. At approximately a quarter of a mile from the airpark and at approximately 500 feet AGL, the engine began to 'sputter.' About 8 seconds later, the engine 'quit.' The airplane continued east and was observed to make a gentle bank to the right and then to the left, but 'the nose was never lowered to establish a glide.' The airplane was observed to stall and spin to the left, rotating about 2 turns before impacting the ground. Postimpact examination of the fuel selector handle and valve revealed they were in the 'off' position.
HISTORY OF FLIGHT On January 8, 1996, at 1657 central standard time, a Smyth Sidewinder, N86S, was destroyed upon impact with terrain following a loss of control near Oklahoma City, Oklahoma. The private pilot was fatally injured. The aircraft was being operated by the owner under Title 14 CFR Part 91. The flight originated from the Sundance Airpark located near Oklahoma City, Oklahoma, at approximately 1655. Visual meteorological conditions prevailed for the cross country flight to Tulsa, Oklahoma, and a flight plan was not filed. According to a witness, the pilot agreed to purchase the airplane from him approximately 1 hour and 15 minutes before the accident. The witness and the pilot flew the accident aircraft locally for an "orientation ride" for "approximately 10 minutes." After landing, the witness put an additional 11 gallons of fuel in the aircraft, in preparation for the pilot's trip home to Tulsa, Oklahoma. The witness further stated that he suggested to the pilot that he takeoff with the fuel selector on the right tank because, of the 3 fuel tanks in the aircraft, it had the most fuel in it. The witness stated that the last time he looked in the cockpit, the fuel selector was on the right tank. According to witnesses, the airplane departed from runway 17 and was observed turning east. At approximately a quarter of a mile from the airpark, when the airplane was approximately 500 feet AGL, the engine began to "sputter." Approximately 8 seconds later, the engine "quit." The airplane continued east and was observed by one witness to make a gentle bank to the right and then to the left, but "the nose was never lowered to establish a glide." The witness further stated that the aircraft "stalled and spun to the left two turns before hitting the ground." PERSONNEL INFORMATION The pilot's previous experience in an aircraft with a header fuel tank was in an experimental home built aircraft called a Thorp, which his father had built. The pilot's father reported to the investigator-in-charge that he and his son had had conversations about why it was safer to takeoff in an aircraft with the fuel coming from a gravity feed fuel tank as opposed to one which required an electric driven fuel boost pump. The Thorp's main fuel tank was a header tank, which because of its location, didn't require an electric boost pump for takeoff. The pilot had approximately 300 to 400 hours flight experience in the Thorp. The witness that sold the accident aircraft to the pilot is currently the owner of the above mentioned Thorp. He stated that in the Thorp, the long end of the fuel selector handle points at the chosen tank, but in the Sidewinder, the short end of the fuel selector handle points at the chosen tank. AIRCRAFT INFORMATION The accident aircraft had 3 fuel tanks, a 15 gallon left tank, a 10 gallon header tank, and a 15 gallon right tank. The aircraft is equipped with an engine driven fuel pump and electric driven fuel boost pump. According to the manufacture, a takeoff can be performed on any of the aircraft's 3 tanks. WRECKAGE AND IMPACT INFORMATION The airplane impacted the ground on a measured heading of 245 degrees, bounced once, and came to rest on a measured heading of 170 degrees, in an open field approximately 1/4 miles east of Sundance Airpark. The leading edges of both wings were compressed aft. The wings remained attached to the fuselage and their respective fuel tanks were compromised. The cabin section aft of the instrument panel and the empennage were intact although the right elevator was broken off. The engine, firewall, and the forward portion of the cabin were broken off. The header fuel tank was compromised. The wooden propeller blades were broken off but the propeller hub remained attached to the crankshaft. The fuel selector valve handle was found in the "off" position. The fuel selector valve was visually verified to be in the "off" position. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy and toxicological tests were ordered and performed. The autopsy was performed by the Office of the Chief Medical Examiner at Oklahoma City, Oklahoma, on January 9, 1996. Toxicological tests were negative. ADDITIONAL DATA The airplane was released to the owner's representative.
The pilot's improper positioning of the fuel selector, which resulted in fuel starvation and loss of engine power, and his failure to maintain sufficient airspeed while coping with the emergency, which resulted in and inadvertent stall and subsequent spin. Factors relating to the accident were: the pilot's lack of experience in type of airplane, and habit interference with respect to use of the fuel selector.
Source: NTSB Aviation Accident Database
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