Accident Overview
Pacific Northern Flight 201 departed from Cordova, Alaska, bound for Anchorage, Alaska. The aircraft failed to maintain its intended track. Mount Gilbert, which rises to an elevation of 9,646 feet, is located approximately 28 nautical miles to the right of the flight's first intended checkpoint. While flying at an altitude of 9,000 feet, the aircraft crashed into the sheer face of Mount Gilbert. All nine passengers and five crew members on board were killed.
Investigation
The investigation into the accident was conducted by the National Transportation Safety Board (NTSB). The Board examined the flight's navigation and the actions of air traffic control facilities involved.
Probable Cause
The NTSB determined that the probable cause of the accident was the failure of the crew to use all available navigational aids in establishing the aircraft's position on Amber I Airway, thereby allowing the aircraft to deviate from course and fly over hazardous terrain. A contributing factor was the failure of Air Defense Radar, which had been tracking the aircraft, to notify either ARTCC or the crew that the aircraft was proceeding on a dangerous course.