American Airlines Flight 320

American Airlines Flight 320 was a scheduled flight between Chicago Midway Airport and New York City's LaGuardia Airport. On February 3, 1959, the Lockheed L-188 Electra performing the flight crashed into the East River during its descent and approach to LaGuardia Airport, killing 65 of the 73 people on board. Weather conditions in the area were poor, and the aircraft descended through dense clouds and fog. As it approached the runway, it flew lower than the intended path and it crashed into the icy river 4,900 feet (1,500 m) short of the runway. American Airlines had been flying the newly-developed Lockheed Electra in commercial service for only about two weeks before the accident, and the accident was the first involving the aircraft type.

After the accident, surviving flight crew members said that the aircraft's instruments had told them that the flight was operating at normal, safe altitudes right up to the moment of impact, but eyewitnesses who saw the aircraft from the ground reported that the aircraft was flying much lower than normal for planes approaching the airport. An investigation by the Civil Aeronautics Board concluded that mistakes by the flight crew, the flight crew's inexperience flying the type of aircraft, and poor weather conditions were the causes of the crash. The Air Line Pilots Association disputed the conclusion, blaming the accident on faulty instruments in the aircraft and poor weather conditions, not on any mistakes made by the highly experienced flight crew.