TWA Flight 514, a Boeing 727, crashes northwest of Dulles International Airport, killing all 92 people on board.

Trans World Airlines Flight 514 was a Boeing 727-231 en route from Indianapolis, Indiana and Columbus, Ohio to Washington Dulles International that crashed into Mount Weather, Virginia, on December 1, 1974. All 92 occupants aboard, 85 passengers and 7 crew members, were killed. In stormy conditions late in the morning, the aircraft was in controlled flight and impacted a low mountain 25 nautical miles northwest of its revised destination. The accident was one of two crashes involving Boeing 727 aircraft in the United States that day, the other being the crash of Northwest Orient Airlines Flight 6231 later that evening near Haverstraw, New York.

The Boeing 727 is an American narrow-body airliner that was developed and produced by Boeing Commercial Airplanes. After the heavier 707 quad-jet was introduced in 1958, Boeing addressed the demand for shorter flight lengths from smaller airports. On December 5, 1960, the 727 was launched with 40 orders each from United Airlines and Eastern Air Lines. The first 727-100 rolled out on November 27, 1962, first flew on February 9, 1963, and entered service with Eastern on February 1, 1964.

Washington Dulles International Airport – commonly known by its former name of Dulles International Airport, by its airport code of IAD, or simply as Dulles Airport – is an international airport in the Eastern United States primarily serving the country's capital city, Washington, D.C. and its surrounding area. It is located 26 miles (42 km) west of downtown Washington, D.C., in Loudoun and Fairfax counties in Northern Virginia.