History of Flight
On July 17, 2014, about 2320 central daylight time, an Air Tractor AT-401B single-engine turboprop airplane, N4223F, was substantially damaged after impacting terrain near Ellis, Kansas. The pilot was fatally injured. The aircraft was registered to Frontier Ag Inc. and operated by Frontier Agricultural Service, Inc., both of Oakley, Kansas. The flight was a positioning flight under 14 CFR Part 91 and was conducted under dark night visual meteorological conditions (VMC). No flight plan was filed.
The aircraft had departed Moritz Memorial Airport (K61) in Beloit, Kansas, about 2245, destined for Oakley Municipal Airport (OEL) in Oakley, Kansas. No witnesses to the accident were found. Evidence at the scene indicated an initial impact scar with debris scattered generally south. The fuselage came to rest upright about 200 feet south of the initial impact point. There was no post-impact fire.
Pilot Information
The pilot, aged 23, held an FAA commercial pilot certificate with a rating for airplane single-engine land. He did not hold an instrument rating. Review of his personal logbook showed an estimated total flight experience of 1,313.9 hours, including 1,030.6 hours in agricultural application, 394.0 hours in turboprop airplanes, and 96.5 hours in the accident airplane type. His only logged night flying in the previous two years consisted of two flights: one on February 24, 2014, and another on August 9, 2013. His only instrument flight experience was 1.4 hours of simulated instrument flying in December 2013, for a career total of 11.4 hours. He completed a flight review on March 12, 2013, and an agricultural pilot knowledge and skills test on March 31, 2013.
Aircraft Information
The single-seat, low-wing, fixed conventional landing gear agricultural application airplane, serial number 401B-1208, was manufactured in 2008. Originally equipped with a 550-horsepower Pratt & Whitney R-1340 radial engine, at the time of the accident it had a 740-horsepower Walter M601-E11 turboprop engine driving an Avia three-blade propeller. The airplane was equipped with a SATLOC GPS system with a light bar guidance and moving map display, but lacked gyroscopic instruments required for instrument flight (rate-of-turn indicator, artificial horizon, directional gyro). It had no autopilot or emergency locator transmitter. Fuel records showed 73 gallons of Jet A fuel were added at K61 before departure; postaccident fuel quality inspection of the refueling facility was satisfactory.
Meteorological Information
The nearest automated weather station, at Hays, Kansas (KHYS), about 14 miles southeast of the accident site, reported at 2335: visibility 10 miles, broken clouds at 1,000 feet, overcast at 3,300 feet, temperature 17°C, dew point 13°C, altimeter 30.10 inHg. Other area observations indicated instrument flight rules (IFR) ceilings at the accident time from central Kansas westward, with visual flight rules (VFR) ceilings eastward. The overall cloud ceiling was relatively stable, but with the gradual upslope terrain and southeasterly wind, lowering IFR ceilings were expected westward. Weather observations indicated no issues after departure from Skyhaven Airport (KRCM) in Warrensburg, Missouri, through the refueling stop at K61, where ceilings were at or above 9,000 feet above ground level. After departure from K61, ceilings lowered to 1,000 feet at KHYS and continued lowering to 700 feet near OEL. AIRMET Sierra, valid at the accident time, forecast IFR conditions with ceilings below 1,000 feet and visibilities below 3 miles with precipitation and mist. Astronomical data showed sunset at 2102 and moonrise at 0026 the following day; at the accident time, both sun and moon were more than 15 degrees below the horizon, providing no ambient light.
Wreckage and Impact
The airplane struck terrain at about 2,175 feet msl in a remote, sparsely populated agricultural field with no ground lighting. The initial ground scar, consistent with the right wingtip, extended about 50 feet on a magnetic bearing of about 167 degrees, ending in a crater 12 to 18 inches deep. The separated propeller and one cockpit door were found in the debris path south of this area. Ground scars and debris curving west led to the fuselage about 200 feet from the initial scar on a heading of 180 degrees magnetic. The forward structure of the fuselage was destroyed, with the windshield, instrument panel, rudder pedal assembly, and aft hopper wall completely separated. The right sidewall of the cockpit was fully detached. The canopy and overhead structure remained intact with less damage. The right wing was destroyed, with all ribs and skins detached from spars; the left wing had damage but remained mostly intact, with the inboard fuel tank impact-ruptured. The flap actuator was found fully retracted. Control continuity was confirmed for rudder and elevator; aileron controls were extensively damaged but the control stick, torque tube, and bellcranks were intact. The fuel shutoff valve was found in the open position. Engine and propeller examinations revealed no pre-impact mechanical malfunctions. Propeller blades exhibited damage consistent with rotation at impact, including leading edge gouging, chordwise striations, and bending opposite the direction of rotation.
Medical and Pathological Information
An autopsy was performed on the pilot by the Office of the District Coroner of the XXIII Judicial District of Kansas. Forensic toxicology by the FAA found no carbon monoxide in blood, no ethanol in vitreous, and no drugs detected in urine. The pilot's most recent FAA second-class medical certificate was issued on January 7, 2014, with no reported medications or significant issues.
Tests and Research
A damaged Motorola Droid cellphone from the wreckage could not yield data. A SATLOC M3 CPU device was examined and GPS positional data was extracted. The GPS data showed the airplane departed K61 about 2245 toward OEL, maintaining a wandering cruise altitude varying from about 3,700 to 3,200 feet msl until 2316, when it began descending and turned left. At 2317:37, the southbound airplane descended to about 2,500 feet msl and slowed. At 2319:03, it began a second 90-degree left turn to an easterly track, climbing to 3,205 feet msl over terrain about 2,200 feet msl. At 2319:25, the last GPS point recorded the airplane eastbound about 2,800 feet northwest of the impact location, with a ground speed of about 125 knots.
Additional Information
FAA Advisory Circular 60-4A and the FAA Instrument Flying Handbook discuss spatial disorientation, noting that obscured horizons or lack of surface references can lead to dangerous attitudes. The FAA Airplane Flying Handbook emphasizes that night flying demands greater use of instruments and that VFR night flights should not be conducted in marginal weather unless both pilot and aircraft are IFR-capable.