Shaping the modern Air Traffic Control: The Grand Canyon disaster

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United Airlines Flight 718
United Airlines Flight 718. (Twitter)


Flight has become one of the safest means of transportation in modern times, but lessons must always be learned from every airplane accident to ensure safety in future flights. The development of commercial aviation has always depended on careful investigation of aircraft crash accidents.

In the early days of commercial aviation, air traffic controllers were not in towers observing the entire airfield. These individuals simply stood near the runways and guided planes in and out of airports waving flags.

Grand Canyon disaster

One particular accident from June 1956 had much to do with shaping our air traffic control (ATC) system. This highly publicized disaster took place over the Grand Canyon in Arizona. A United Airlines passenger airliner (Flight 718) struck a Trans World Airlines airliner (TWA Flight 2) over the Grand Canyon resulting in a mid-air collision. Both flights had taken off from Los Angeles airport only minutes apart.

There were no survivors from either plane, and the crash had become the worst accident in aviation history up to this point. Yet this disaster would become the inspiration for sweeping changes of ATC in the U.S.

The turboprop airplanes involved in the accident were the most modern of its time—Lockheed Super Constellation and Douglas DC-7.

In the 1950s, the system used to track flight traffic was still relatively primitive. While they were already in towers by this point, air traffic controllers would position planes on printed maps based on speed and altitude readings obtained through radio communication with the pilot.

This system only gave controllers a rough estimate of each plane’s best known position; they did not have an exact idea of an aircraft’s location. The U.S. terrain was not covered by radar in the late 50s, so planes at that time were flying by the rule: “see and be seen.”

With very little radar on the ground to track planes in the air, a craft out of radar range could only be located based on the speed and altitude estimates last reported form pilots while still in radio controlled areas.

In the 1956 flight disaster, the two planes were flying at the same altitude and almost at the same speed when they approached the Grand Canyon. Both crews had to weave around towering clouds, as flying in uncontrolled radar airspace required that they remain visible at all times.

Maneuvering over the canyon, it is believed that both planes passed by the same cloud formation at the same time, without ever knowing that they were on a collision course.

The crash was shocking to a public that had previously had a growing confidence in air travel. The collision was an alarm bell for the entire nation. Something needed to be done to prevent such accidents in the future.

The public was outraged when they learned that the ATC system was inadequate and unable to meet the demands of the increased air traffic becoming a potential for another disaster.

As a result, the government was pressured to take immediate action to solve the problem. It became clear that more radar was needed to control flight traffic, and the ATC system received a substantial update.

In 1957, congress allocated considerable funding to employ and properly train more controllers to modernize the ATC. Yet despite these steps, aircraft collisions still remained a threat.

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Ian Powers is a travel blogger and nature enthusiast. Ian has over 20 years of aviation travel experience.

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