What happened
Radar data indicated that the light twin-engine airplane was climbing at approximately 500 feet per minute before the rate steadily decreased to 350, 240, and eventually 140 feet per minute over a 24-minute period leading up to the impact. Witnesses fishing in the vicinity reported hearing an aircraft fly overhead, followed shortly by a loud explosion near a mountain peak. This was accompanied by observations of a rockslide, dust, and a plume of smoke.
The wreckage was discovered by the sheriff's office. The initial point of impact occurred at approximately 12,800 feet MSL, with the main wreckage coming to rest at 12,500 feet MSL.
The investigation
The investigation examined flight routes and altitude requirements. While company manuals proposed two instrument flight rules routes with minimum en route altitudes (MEA) of 13,000 feet and 15,000 feet, a direct flight path travels over terrain with peaks reaching 14,100 feet MSL. The Air Route Traffic Control Center reported that the MEA for a direct flight is 15,300 feet MSL.
Information gathered from colleagues, friends, and family indicated that the pilot was experiencing significant fatigue and symptoms of burnout. Reports suggested the pilot had fallen asleep while acting as pilot in command during extended flights, and passengers had noted similar incidents. Furthermore, the pilot's schedule frequently involved being awakened in the middle of the night for work. On the morning of the accident, the pilot had requested a companion for the flight due to tiredness.