Accident Overview
On a cargo flight from Travis Air Force Base (AFB) to Clark Air Base, Philippines, a four-engine airplane operated by the United States Air Force (USAF) with intermediate stops at Cold Bay Airport and Yokota Air Base struck the slope of Mt Dutton during nighttime approach to Cold Bay. The aircraft was flying at an altitude of 3,500 feet when it impacted the 4,941-foot-high mountain, located 18 miles east of Cold Bay Airport. The airplane was totally destroyed, and all six occupants were killed.
Events
The flight departed Travis AFB and proceeded with planned stops. While approaching Cold Bay at night, the crew encountered marginal weather conditions. At the time of impact, the aircraft was at a speed of 185 knots and on a heading of 275°. The airplane was off course by 12° from the intended track.
Probable Cause
The official probable cause, as determined by the investigation, was the captain's deviation from approved instrument approach procedures. As a result of the deviation, the flight descended into an area of unreliable navigation signals and obstructing terrain.