ERA16LA068

The sport pilot of the experimental, amateur-built airplane was the last to takeoff in a group of three airplanes. After takeoff, the airplane entered a steep climb, banked sharply left, and then descended rapidly in a manner consistent with an aerodynamic stall and spin. Examination of the airplane did not reveal evidence of any preexisting mechanical anomalies that would have precluded normal operation. It is likely that, during the initial climb, the pilot failed to maintain control of the airplane, which resulted in the exceedance of the airplane's critical angle of attack and an aerodynamic stall/spin. Although the pilot had coronary artery disease, and he was taking clozapine, a drug that can cause seizures or cardiac arrest, it could not be determined whether the pilot was impaired or incapacitated at the time of the accident.

On December 12, 2015, about 1440 eastern standard time, an experimental, amateur-built RANS S-12 Airaile airplane, N6202N, was substantially damaged when it impacted the ground shortly after takeoff from Chilhowee Gilderport (92A), Benton, Tennessee. The sport pilot was fatally injured. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan had been filed for the flight to a private airstrip in Athens, Tennessee.According to witnesses, the airplane was the third in a group of three to take off from runway 21 at 92A. Witnesses noted that, after the takeoff, the airplane made a "rapid" or "steep" climb at the top of which it began a left turn. One witness noted that the airplane then entered a "steep wingover-like 180° turn reversing to the north." The airplane was then "in a low energy state," about 150 ft above ground level (agl) at a high rate of descent with "the left wing [then] lowering in what can only be described as a 1/2- to 3/4-turn spin, impacting the ground with the left wing and nose." Another witness noted that the airplane "appeared to stall, hovered for a split second and twisted in a nose dive into [a] sod field." A third witness stated that the airplane was in a left bank of about 70° to 80° and subsequently "descended rapidly then 'nosed over' and impacted the ground in a near vertical attitude." A fourth witness, who was inside at the time, stated, "I heard the crash; the sound of the engine was loud and even right up to the moment of impact." The accident site was located in an open grass field about 360 ft southeast of runway 21. According to a local law enforcement incident report, the airplane impacted terrain inverted and was subsequently righted by first responders. A Federal Aviation Administration (FAA) inspector's examination of the airplane did not reveal evidence of any preexisting mechanical anomalies that would have precluded normal operation. Photographs of the airplane showed crush damage to the forward section of the fuselage and the leading edges of both wings. All major flight control surfaces remained attached. The engine remained attached to the airframe. The propeller hub remained attached to the engine. Two of the wooden propeller blades were fragmented near the propeller hub, and one blade fragmented near the tip. According to FAA airman records, the pilot held a sport pilot certificate. He also held a light sport aircraft repairman certificate that was limited to N4288S, a Quad City Challenger II, serial number GC6151954. The pilot did not hold a medical certificate nor was he required to for the accident flight. The pilot's logbook was not located. According to FAA airworthiness records, the two-seat, single-engine airplane was manufactured in 1992. It was powered by a 100-horsepower Bombardier Rotax 912 engine. The airplane's airframe and enginelogbooks were not located. According to a specifications sheet provided on the kit manufacturer's (Rans Aircraft) website, the airplane's aerodynamic stall speed with flaps retracted was 42 mph and with flaps extended was 35 mph. The airplane's flap setting at the time of the accident was not determined. A witness at the airport reported that the wind was from the south at 8 to10 miles per hour. The weather conditions reported at McMinn County Airport (MMI), Athens, Tennessee, about 10 nautical miles north of the accident site, included wind from 230° at 7 knots, visibility 10 statute miles, few clouds at 5,000 ft agl, temperature 21°C, and dew point 13°C. The Center for Forensic Medicine, Office of the Medical Examiner, Nashville, Tennessee, performed an autopsy on the pilot. The autopsy report noted the cause of death as "multiple blunt force injuries." The autopsy also revealed that the pilot had significant coronary artery disease with 70-80% stenosis of the left anterior descending artery and 50-60% stenosis of the right coronary artery. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing on samples from the pilot. The testing identified clozapine, an antipsychotic medication known to increase the risk of a number of medical conditions including seizures and death, and propranolol, a non-impairing medication most often used to treat hypertension.