Air Tractor AT 502-B Crash at Treinta y Tres Airport (CX-QCH-R)

Incident Overview and Flight Details On December 18, 2013, an agricultural aircraft operated by Charles Chalkling S.A. crashed near the Aeropuerto Departamental de Treinta y Tres in Uruguay. The aircraft, an Air Tractor AT 502-B with registration CX-QCH-R, was conducting a transfer flight to a temporary agricultural airstrip located 38.5 km away. The mission involved applying urea to two farms of 166 and 159 hectares, a task estimated to take four hours. The aircraft was fueled with 400 liters of fuel, providing an estimated two hours of flight time, while the transfer leg was expected to take approximately 10 minutes. ## Operational Context and Weather The pilot, who was the sole occupant, prepared for the flight at the company's facilities. The support team had previously moved the aircraft out of the hangar and then departed for the work site, leaving no one to assist with the flight's departure. Due to morning fog and mist, which are common in the area during that time of year, the pilot contacted the support team to check weather conditions at the destination. The team reported that conditions were good, free of fog, and had good visibility. The pilot also referenced data from a portable weather station at the company's site. ## Takeoff and Crash Sequence The aircraft took off from runway 19 at approximately 06:08 local time, heading 190 degrees. Other agricultural aircraft were waiting at the airport for weather improvements due to the fog. As the pilot taxied past the parked aircraft, he turned on the strobe lights, which surprised the other pilots; one of them filmed the event with a mobile phone. After takeoff, the aircraft entered a layer of fog or mist and disappeared from view. Witnesses reported hearing a change in the engine sound, as if the aircraft were turning right. A few minutes later, an explosion was heard, and a fire was visible south of the aerodrome. The crash occurred at approximately 06:10 local time in daylight. ## Aftermath and Investigation The pilot was killed in the accident. The aircraft was destroyed by the impact and subsequent fire, which was fought by the local fire brigade. The investigation was conducted by the Comisión Investigadora de Accidentes e Incidentes de Aviación (C.I.A.I.A.) under the authority of Uruguay's National Ministry of Defense. The investigation included field work, witness interviews, aerial and police photography, video of the takeoff, and a technical report from Pratt & Whitney Company regarding the engine. The report also referenced FAA Aviation Safety materials on spatial disorientation.