Background
Alaska Airlines Flight 1866 was a regularly scheduled passenger service operating from Anchorage, Alaska, to Seattle, Washington, with multiple intermediate stops in southeast Alaska. The aircraft involved was a Boeing 727-100, registered as N2969G and manufactured in 1966.
Accident
On September 4, 1971, while on approach for landing at Juneau, the aircraft crashed into a mountain in Haines Borough, approximately 18 miles west of Juneau. All 111 persons on board were killed. This event marked the first fatal jet aircraft accident involving Alaska Airlines and remained the deadliest single-aircraft crash in United States history until Eastern Air Lines Flight 66 on June 24, 1975. It continues to be the worst air disaster in Alaska state history.
Investigation
The subsequent investigation determined that erroneous navigation readouts led the flight crew to descend prematurely. However, no definitive cause for the misleading navigation data was identified.
Aftermath
The crash prompted various safety discussions, but the investigation concluded without pinpointing why the navigation system provided incorrect information.