What happened
On the afternoon of the accident, a British Eagle BAC One-Eleven departed from London-Heathrow Airport, scheduled to land in Innsbruck, Austria. At approximately 13:35 GMT, the flight crew communicated with Munich Air Traffic Control and subsequently reported passing over the Kempten NDB. During this period, the crew requested a change in their flight plan, transitioning from instrument flight rules (IFR) to visual flight rules (VFR) for the remainder of the journey toward Innsbruck.
Shortly after, the crew notified Innsbruck controllers that they were descending under visual meteorological conditions (VMC) with a direct route to Seefeld. While positioned over the Innsbruck VOR at flight level 110, the aircraft was still unable to penetrate the cloud layer. The final communication from the cockpit occurred at 14:12 GMT, at which time the aircraft was at flight level 100.
As the descent continued, the aircraft struck the eastern side of the Glungezer Mountain at an elevation of 2601 meters (8500 feet). The impact triggered an avalanche that moved much of the wreckage approximately 400 meters down the slope. There were 83 fatalities and no survivors.
Findings
Investigations determined that the pilot-in-command made the incorrect decision to descend below the required minimum safe altitude given the prevailing weather conditions. This descent prevented the crew from maintaining the necessary visual references required to operate under VFR.