Federal air traffic control began on July 6, 1936, when the Bureau of Air Commerce took over the operation of the first airway traffic...

The Federal Aviation Administration has marked the 75th anniversary of air traffic control in the U.S., as American aviation experiences what the Department of Transportation says is its safest period ever.

Federal air traffic control began on July 6, 1936, when the Bureau of Air Commerce took over the operation of the first airway traffic control centers at Newark, New Jersey; Chicago; and Cleveland.

Faced with a growing demand for air travel, the 15 employees who made up the original group of controllers took radio position reports from pilots to plot the progress of each flight, providing no aircraft-separation services. 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 (with several stop en route to refuel) while carrying 21 passengers.

Since then, the U.S. air traffic system has expanded from three control centers to include 131 federal stand-alone airport traffic control towers, 132 towers for terminal area approach control, 29 stand-alone terminal radar approach controls and 21 en route traffic control centers.

A line of aircraft wait on a taxiway at Hartsfield-Jackson Atlanta International Airport to turn on to a runway for take-off. Hartsfield-Jackson is the world's busiest airport both for aircraft movements and for passengers

The number of controllers has grown from 15 to more than 15,000, a workforce that handles an average of 50,000 flights each day. The DC-3 has given way to jet aircraft that can carry hundreds of passengers and fly from New York to Los Angeles in about five hours.

“The United States has the safest air transportation system in the world. But as the last 75 years show, we will never stop working to make our system even safer,” said U.S. Transportation Secretary Ray LaHood in a statement.

“As a pilot, I am in awe of the aviation safety and technological advancements that have been made in the last 75 years,” said FAA Administrator Randy Babbitt. “NextGen represents the next milestone in aviation innovation. The FAA is committed to transforming our national airspace system so passengers can reach their destinations even more safely and more efficiently than they do today.”

The FAA’s planned Next Generation Air Transportation System, or NextGen, is intended to transform air traffic control in the U.S. from a system of ground-based radars to one based on satellites.

In parts of the country, controllers already are beginning to track aircraft via satellites with a state-of-the-art system called Automatic Dependent Surveillance – Broadcast, or ADS-B. ADS-B will be available nationwide in the U.S. in 2013 and will enable more direct routes, saving time and money while also lowering the industry’s environmental footprint.

Throughout July, the FAA will celebrate the 75th anniversary of federal air traffic control by issuing public information highlighting advancements in air traffic controller training, NextGen, how the FAA handles convective summer weather and aviation infrastructure improvements.