History of Flight
On July 23, 2010, at 2020 central daylight time, an experimental amateur-built Warth Classic Sport S-18, N216TB, sustained substantial damage when it impacted a cornfield after a loss of engine power shortly after takeoff from runway 16 (3,650 feet by 60 feet asphalt) at Lincoln County Airport (Y14), Tea, South Dakota. The commercial pilot was fatally injured. The flight was a local personal flight under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed; no flight plan was filed.
A witness who spoke to the pilot before the flight stated the pilot intended to conduct a maintenance test flight after installing a throttle body fuel injection system, new engine baffles, and a Vans RV-4 intake scoop. The witness observed the pre-takeoff engine run-up: on the first attempt the engine hesitated and failed to reach full RPM; on the second attempt it “went flat and lost RPM”; the third run-up was successful. The takeoff roll appeared normal, with full power. The airplane rotated and climbed to about 500–600 feet above ground level (agl). It entered a left crosswind turn. The witness saw a “brief puff” of dark black smoke from the exhaust. The airplane, about 1/2 mile from the airport, began losing altitude while continuing the left turn, until it was headed west. The witness stated, “The aircraft entered a full stall, probably 150 to 200 feet off the ground.”
Another witness reported the airplane pitched up about 100–150 feet agl, then entered a hard right turn. It impacted the cornfield in a 50–60 degree nose-down attitude, with the left wing and nose hitting first.
Personnel Information
The pilot, age 31, held a commercial pilot certificate with single-engine and multi-engine airplane land and an instrument rating. He held a second-class medical certificate issued September 2009. Logbook records showed about 3,366 total flight hours and about 65 hours in make and model. The last recorded flight was November 18, 2009.
Aircraft Information
The two-seat, low-wing, experimental amateur-built Warth Classic Sport S-18 (serial number 245) was powered by a Lycoming O-320-D2A 180-horsepower engine with a Sensenich propeller. The airframe had about 123 total hours; the last conditional inspection was February 22, 2010. A Rotec Throttle Body Unit and regulator had been installed, replacing the original carburetor.
Meteorological Information
At 1956, the surface weather at Joe Foss Field Airport, Sioux Falls (8 miles north), reported: wind 150° at 8 knots, visibility 10 miles, broken ceiling at 3,800 feet, temperature 28°C, dew point 23°C, altimeter 29.76 inHg.
Wreckage and Impact Information
The wreckage was in a cornfield near the airport. Impact damage was consistent with an inverted impact at 60–70° nose-down attitude. The right wing was separated and found about 30 feet from the main wreckage.
FAA inspectors examined the wreckage. The airframe showed no pre-impact anomalies. The engine was removed for inspection with assistance from an A&P mechanic. Both magnetos were broken and could not be tested. Cylinder 2 was removed; no internal drive train damage was noted. Compression and suction were confirmed on the remaining cylinders. Drive train continuity was established. The mechanical fuel pump was broken in two; fuel was present in lines to the regulator and throttle body. All throttle body control cables were connected. The propeller blades were bent aft with no chordwise scoring, leading edge gouges, or nicks.
The Rotec Throttle Body unit and regulator were sent to the NTSB for testing. They were visually inspected and installed on a recently overhauled Lycoming O-320 on a test stand. No leaks were found. The engine ran smoothly at 1,500, 2,000, and 2,500 RPM. At 2,600 RPM and 26 inches manifold pressure, the engine sounded slightly rough. No anomalies were noted.
Medical and Pathological Information
An autopsy of the pilot was conducted on July 24, 2010. The cause of death was multiple blunt trauma secondary to an airplane accident. The FAA toxicology report tested negative for carbon monoxide, cyanide, and ethanol. 38.92 µg/ml acetaminophen was detected in urine.