TWA Flight 514 Crash Exposes Flaws in Air Traffic Control

On December 1, 1974, TWA Flight 514, a Boeing 727-231 carrying 85 passengers and seven crew members, crashed into Mount Weather in Virginia while descending for an instrument approach to Washington Dulles International Airport. The accident resulted in the loss of all 92 people aboard.

The flight was diverted from its original destination of Washington National Airport due to high crosswinds, and controllers progressively cleared the aircraft to lower altitudes as it approached Dulles. However, the crew misunderstood an approach clearance, descending to 1,800 feet before reaching the segment where that altitude applied.

An investigation by the NTSB found that unclear ATC procedures contributed to the fatal descent, with both the pilot and controller having different understandings of their responsibilities in instrument meteorological conditions. The Board also found that the approach chart's plan view should have shown the captain that 1,800 feet was not safe at the aircraft's position.

The accident led to significant changes in air traffic control procedures, including the issuance of explicit IFR approach-clearance wording and the installation of ground proximity warning systems (GPWS) on commercial fleets. The FAA revised rules covering pilot responsibilities after a nonprecision approach clearance and established an incident-reporting system.