Flight History
The pilot contacted air traffic control using an incorrect call sign and requested radar flight following. The airplane initially climbed to 13,500 feet, then descended to 11,500 feet, climbed again to 13,500 feet, and finally began a descent that ended when it impacted terrain at 11,900 feet. One minute before impact, the pilot queried the controller about various minimum altitudes for his route. The controller responded that the minimum instrument altitude was 15,000 to 15,300 feet.
Air Traffic Control Interaction
A review of the handling of the flight showed that the controller was aware of the airplane's position, altitude, general route of flight, and its proximity to terrain. Despite this awareness, no safety alert was issued to the accident flight.
Weather Conditions
Weather depiction charts, infrared satellite imagery, and local weather observations indicated that instrument meteorological conditions (IMC) prevailed along the route of flight near the accident location. The moon had set at 1539 on the day of the accident. The pilot reported a planned flight altitude of 12,500 feet to his dispatcher. No record of a preflight weather briefing was located.
Aircraft Examination
An examination of the airplane, engines, and related systems revealed no anomalies that would have contributed to the accident.