Air Traffic Control: The Backbone Of Aviation

The air traffic control tower at Newark Liberty International Airport.

You’ve all probably heard of air traffic control (ATC), but why does it exist and where did it come from? As the popularity of air travel grew, so did the need for better air traffic control around airports. Airlines first developed systems to control their own air traffic. However, a series of highly publicized accidents in the mid-1930s highlighted the critical need for a national system of standardized air traffic control. As a result, in 1936, the Department of Commerce of the federal government established nationwide air traffic control. However, contrary to popular belief, there was already progress towards creating a national air traffic control system before the Department of Commerce got involved. In February 1931, the route from New York to San Francisco was already equipped with radio range stations. These radio-transmitting stations sent a signal that not only carried identification but also signaled a pilot to fix their position/flight path.

In December 1935, the airlines established the first airway traffic control center in Newark, New Jersey, followed by two more in Cleveland and Chicago. As stated before, in 1936, the Department of Commerce eventually took over, as they realized the importance of having safe air travel. Within a year, there were many air traffic control centers across the country. An airway modernization program called the Civil Aeronautics Act was launched in 1938, creating many more airport control towers. The act’s goal was to improve air traffic management, safety regulations, and economic practices in aviation.

The primary purpose of the control towers was to prevent collisions, organize and manage the flow of air traffic, and provide information and support for pilots. These towers later became crucial, as three years later, World War II would end up happening. When World War II ended, two landing systems were created and used: Ground Controlled Approach (GCA) and Instrument Landing System (ILS).

Landing Systems

Ground Control Approach (GCA) is a type of landing where air traffic controllers guide the pilot to the runway using radar and radio communication. It's mostly used in military operations or when other landing systems fail. Although GCA was popular with the military, airline pilots preferred the competing ILS system. The Civil Aeronautics Authority, in 1947, decided that the Instrument Landing System (ILS) would be the primary landing system, while the GCA system would be used for additional support at busy airports. With ILS, pilots received altitude and direction data from radio transmissions, and this allowed the pilot to follow a glide path to the runway. Compared to GCA, ILS reduced missed approaches and flight cancellations, and it enabled airports to handle more traffic.

New Advancement

Radar technology was developed by the British in the 1930s and was used during World War II. The U.S. later adopted this, with the first control tower with radar technology being built at Indianapolis Airport in 1946. By 1951, the use of radar had begun to replace pilot-reported positions by radio. Radar departure control made its first ever appearance at Washington National Airport—now called Ronald Reagan Washington National Airport—in 1952. Until then, radar had only been used to identify where an aircraft was headed. Now with the new system, control towers were able to make way for better and safer traffic flow in and out of airports.

Issues Arise

Despite many advancements and improvements in air traffic control, a series of accidents in 1951 and 1952 sparked public concern. These accidents led to more technical developments and encouraged new discussions on safety and traffic control. In addition, air traffic growth in the 1950s led to severe airport congestion and delays. In 1956, two airliners collided over the Grand Canyon. Two more collisions occurred in 1958, and another one happened in 1960. These events prompted legislation to enable aviation authorities to take corrective measures. In the 1950s, the Civil Aeronautics Administration began installing long-range radars with a range of up to 200 miles. A network of connected radars was completed by 1965, allowing for the monitoring of aircraft in controlled airspace throughout the nation.

Air Traffic Control Today

Every day, thousands of aircraft safely cross the skies over the United States thanks to the advancements made in air traffic control. Each is carefully watched and directed to its destination by an interconnected system of air traffic controllers. Air traffic control towers are located at over 500 airports in the United States, coordinating takeoffs, landings, ground traffic, and aircraft in flight. However, air traffic issues caused by weather have not been resolved. Severe weather causes more than 70% of air traffic delays and costs airlines billions of dollars every year. However, air traffic controllers still work constantly to minimize weather disruptions, while ensuring that every flight arrives safely. Despite the severe challenges presented by weather and things like airport congestion, the Federal Aviation Administration's professional workforce ensures that aviation remains safe.