The Origins and Evolution of Air Traffic Control

In early 2025, it felt like everyone on the internet became an air traffic control expert overnight. After the midair collision over the Potomac River in late January, my feeds filled up with confident explanations of what was broken, who broke it, and how to fix it by next Tuesday. Most of those explanations contradicted each other.

I realized I didn’t know enough to have an opinion, so I started reading. This series is the result: six articles on where air traffic control came from, how it works today, why it’s so hard to upgrade, and the arguments over how to fix it.

A note before we start: I’m not an air traffic controller, a pilot, or an aviation regulator. I’m a technologist who spent a lot of evenings with FAA histories, government audit reports, and more than a few Wikipedia rabbit holes. I’ve worked to get the facts right, and sources are listed at the bottom of each article. For anything authoritative, go to the FAA, ICAO, or EUROCONTROL. If you know this world better than I do and spot a mistake, please tell me.

Flags and a Beach Umbrella

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For the first couple of decades of powered flight, there was no air traffic control. Pilots flew by “see and be seen,” which works fine when there are three airplanes in the sky and progressively less fine after that.

Croydon Airport, outside London, is generally credited with introducing the first air traffic control in 1920. Controllers there used radio to give pilots position, weather, and traffic information, which beat the previous system of hoping for the best.¹

In the United States, the job started with a man named Archie League. In 1929, the city of St. Louis hired him to direct traffic at its airfield. His equipment was a wheelbarrow, a beach umbrella, a chair, and a pair of flags: checkered meant go, red meant hold. (Somewhere, a modern controller is looking at a radar scope with a renewed sense of gratitude.) When the airport installed a radio a few years later, League became its first radio controller.² Cleveland opened the first radio-equipped airport traffic control tower in the US in 1930.¹

The rules of the road were taking shape internationally, too. The 1919 Paris Convention set up the International Commission for Air Navigation, which was eventually replaced by the International Civil Aviation Organization (ICAO) after the 1944 Chicago Convention. ICAO still writes the international standards that controllers and pilots work under today.³

The Airlines Built It, Then Washington Took Over

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Towers handle the airport. The harder problem is the airspace between airports, and the first people to tackle it were the airlines. A group of airlines opened the first airway traffic control center in Newark in 1935, followed by centers in Chicago and Cleveland in 1936.¹ That same year, the federal government took over the centers, and air traffic control has been a federal job in the US ever since.

The Civil Aeronautics Act of 1938 put civil aviation under a single federal agency, the Civil Aeronautics Authority, later reorganized into the Civil Aeronautics Administration. Then World War II arrived and brought radar with it. After the war, radar moved into civilian air traffic control and changed the job completely. Controllers could see aircraft instead of relying entirely on position reports and mental math.

The Accident That Created the FAA

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On June 30, 1956, TWA Flight 2 and United Air Lines Flight 718 collided over the Grand Canyon, killing all 128 people on board both aircraft. At the time, it was the deadliest commercial aviation accident in US history.⁴ Both airplanes were flying in uncontrolled airspace, where staying apart was still the pilots’ job. The air traffic control system of 1956 was largely running on 1930s methods, and the accident made that impossible to ignore.

Congress responded with the Federal Aviation Act of 1958, which created the Federal Aviation Agency and gave it responsibility for both air traffic control and safety regulation. When the Department of Transportation was created in the late 1960s, the agency moved under it and became the Federal Aviation Administration, the FAA we know today.⁴

Through the 1960s and 1970s, the FAA put computers into its en route centers and terminal radar facilities. Instead of tracking each flight on paper and memory, controllers started seeing an aircraft’s identity and altitude displayed right next to its radar target. That sounds basic now. It was a big deal then.

1981: The Strike

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On August 3, 1981, the Professional Air Traffic Controllers Organization went on strike. President Reagan ordered the controllers back to work within 48 hours, and on August 5 he fired the 11,345 who didn’t return.⁵ The FAA kept the system running with supervisors, the controllers who stayed, and military controllers, but rebuilding the workforce took close to a decade. Training a controller normally takes years, and you can’t hire experience.

I bring this up because it matters later in the series. A workforce hired in one big wave tends to retire in one big wave, and staffing has been a sore spot for the FAA ever since.

That same year, the FAA published the National Airspace System Plan, an ambitious program to replace much of the system’s aging equipment. Its centerpiece was a massive software project called the Advanced Automation System. We’ll get to how that went in part four. (Spoiler: not well.)

Satellites Enter the Picture

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The Global Positioning System became fully operational in 1995, and it opened the door to a different way of thinking about air traffic control. If every aircraft knows exactly where it is, why not have it broadcast that position to controllers and other aircraft? That idea became ADS-B (Automatic Dependent Surveillance–Broadcast), which the FAA began testing in Alaska around 2000, where radar coverage is thin and the terrain is unforgiving.

In 2003, Congress passed the Vision 100 – Century of Aviation Reauthorization Act, which launched the Next Generation Air Transportation System, better known as NextGen.⁶ NextGen was supposed to move the US from a radar-and-voice system to one built on satellite navigation and digital communication. Europe started its own version, SESAR, a few years later. Both programs are still going, which tells you something about how hard this is.

A Pattern Worth Noticing

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Reading through this history, one thing stood out to me. Many of the biggest changes to air traffic control came after something went badly wrong: a collision, a strike, a near-disaster. The system gets better, but it tends to get better in response to tragedy rather than ahead of it. That’s part of why the conversation after the Potomac collision got so heated so quickly.

Next up: The Modern Air Traffic Control System: Technology and Operations, a look at how the system actually works today.

References

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