Aircraft Accident/Incident Report

Flagstaff, Arizona 86001
Tuesady, December 7, 2004 19:55 MST

The aircraft collided with an embankment 2 miles from, and about 200 feet lower than, the airport during a takeoff attempt in icing conditions. Examination of the ground scars and wreckage disclosed that the airplane collided with the berm in near wings level controlled flight while in a slightly nose high descending flight path. Evidence showed that both engines were developing symmetrical high power at impact. The aircraft was transporting cargo and medical specimens over a route the pilot flew every day according to a company schedule. The aircraft had arrived at 1826 from the previous stop on the scheduled route. According to witnesses at the airport who watched the airplane takeoff, either one or both of the engines were "very rough sounding." After the airplane departed runway 21, it made a shallow left turn, and then disappeared into the low clouds. One witness indicated that the airplane rotated approximately 5,000 feet down the nearly 7,000-foot-long runway. While on the ground after arrival, the pilot requested that the airplane be deiced. The line service technician accomplished this at 1855, 1 hour before the accident, with the pilot observing the procedure. When the technician arrived at the aircraft he noticed that the aircraft had "a considerable amount of ice built up" from the landing. He sprayed approximately 5 gallons of Glycol mix 50/50 to remove the ice and snow that was attached to the leading edges of the wings, spinners, and the snow that had accumulated on the top of the fuselage. During the procedure, light snow continued to fall. The accident airplane was not certified, nor equipped for flight into known icing conditions. Based on an evaluation of the weather data, IFR conditions, light snow showers, and conditions highly conducive to icing from the surface to 20,000 feet existed at the airport during the aircraft's landing, stay on the ground, and departure. There was a 95 percent probability of moderate clear to mixed icing from the surface to 10,800 feet. The pilot was aware of the icing conditions both at the airport and in the local area at the time of departure, and had received multiple weather briefings where the forecasted and observed icing conditions were clearly described. The operator reported that a truck was available to take the pilot's cargo onto the final destination should weather or mechanical reasons preclude completion of the flight. According to entries in a journal the pilot kept, there is evidence that the pilot perceived a great deal of pressure to fly in icing conditions with an under-equipped aircraft, and some of this pressure involved a perceived association between doing so and maintaining employment; however, there was insufficient information to determine whether the company culture condoned or encouraged this behavior. There was insufficient information from which to determine why the pilot chose to depart in icing conditions. Fatigue was not a factor in this accident. No preimpact mechanical malfunctions or failures were identified in the wreckage examinations.

The pilot's decision to attempt flight into known adverse weather conditions beyond the capability of the airplane and his failure to ensure that the airplane's wings were free of ice and/or snow contamination that accumulated while the airplane was on the ground, which resulted in an attempted takeoff with upper wing contamination that induced a subsequent stall/mush and a collision with the ground.