July 12, 2011 ATC's 75th Anniversary

The Liberty Gazette

July 12, 2011

Ely Air Lines
By Mike Ely and Linda Street-Ely


Linda: The press release from Washington hit my inbox a few days ago heralding the 75th anniversary of federal air traffic control. Our nation's Air Traffic Control system has grown from just three air traffic control centers, housing a total of 15 workers in 1936 to 313 federally operated air traffic control facilities housing more than 15,000 workers. There are also control towers staffed by contract employees. Conroe is one example.

Those 15 original employees worked in Newark, Chicago, and Cleveland. Looking back at how air traffic control first operated underscores the tremendous advancements made in safety, speed, and economy. Controllers back then took radio position reports from pilots to plot the progress of each flight. They were not yet providing separation services (separation between airplanes). In fact, they didn’t even speak directly to the pilots flying the airplanes. At the time, the fastest plane in the commercial fleet was the Douglas DC-3, which could fly coast-to-coast in about 17 hours carrying 21 passengers. Today’s air traffic controllers not only provide separation services but do so for an average of 50,000 flights per day.

The DC-3 can comfortably claim its place in history. One of my all-time favorites, it is a real work horse and deserves respect as a great airplane. But speed up we have, and today’s jet airliners can carry hundreds of passengers and fly from Los Angeles to New York in about five hours, improving efficiency (as long as you don’t count the time it takes to get to the airport, park, stand in line and be accosted by the TSA).

Mike: But back to the early days. As with all good ideas, the necessity of some sort of organization to air traffic led to the development of local air traffic control before the federal government jumped on board. By 1926 legislation authorized the Department of Commerce to “establish air traffic rules…for the prevention of collisions between vessels and aircraft.” The first rules were brief and basic: pilots were not to begin their takeoff until “there is no risk of collision with landing aircraft and until preceding aircraft are clear of the field.”
Apparently a little more direction was needed. Procedures to control local air traffic began in 1929 at an airport in St. Louis, Missouri. A person would stand at the end of the runway using colored flags to communicate advisories to pilots. Flags were replaced by light guns, which are still required to be available for use in control towers today in the event of radio failure.

As aircraft were fitted for radio communication, airport traffic control towers began replacing the flagmen with radio operators. In 1930, the first radio-equipped control tower in the United States began operating at the Cleveland, Ohio Municipal Airport. Within the next five years about 20 radio control towers were in use and almost all airline aircraft had radio-telephone communication, although direct communication between pilots and controllers was still to come. En route airline crews communicated via radio with their company dispatchers who would in turn call the air traffic controllers, who tracked the position of planes using maps and blackboards and little boat-shaped weights.

From flagmen on the ground to GPS satellites in the sky, we’ve come a long way making air travel safer, faster, and more affordable.

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