Non-radar air-traffic system debuts

Updated 6m ago
By Alan Levin, USA TODAY

Airline flights are being closely tracked and directed without radar for the first time in the nation's history as part of a new system monitoring the skies above the Colorado Rockies.

The program is a look ahead to the way air-traffic controllers may soon monitor planes across the USA. It uses similar technology to the satellite-based system that the Federal Aviation Administration (FAA) is installing nationwide to replace radar over the next decade, said Vincent Capezzuto, who oversees the agency's modernization technology.

Capezzuto said the idea is "all part of the big picture" in planning for future generations of air-traffic control and for trying to reduce flight delays.

The new system uses 20 sensors clustered around four airports within the Rockies. The sensors monitor radio broadcasts from planes. By measuring minute differences in the time it takes for the broadcasts to reach the various sensors — as slim as 10 billionths of a second — computers can determine a plane's location, said Ken Tollstam, vice president of Sensis, which built the devices.

Since the 1950s, radar has been the backbone of the air-traffic system, allowing controllers to monitor the growing number of flights and prevent mid-air collisions. But its technical limits have made airports inefficient, leading to flight delays. The government plans to shift to a more accurate satellite-based tracking system by 2020.

Experts said the success of the Colorado program, which was certified for use by controllers last month, is a sign that the technology underpinning the satellite system can work.

"It's a major shift in how we do business and it is one of the beginning signs that we are modernizing the system," said John Hansman, a Massachusetts Institute of Technology professor who studies air-traffic issues.

Though it had never been used to guide planes in the air in this country before, the technology behind the Colorado system has been used at dozens of airports to track planes on the ground.

Controllers at an FAA facility in Longmont, Colo., can now monitor planes all the way to the ground at airports that previously had no radar coverage. The new system follows flights to Yampa Valley Airport in Hayden, Colo., which has large jet service from several airlines. It also covers three airports serving private planes in the towns Steamboat Springs, Craig and Rifle.

The system should offer dramatic improvements for skiers flying to resorts such as Steamboat Springs, according to the FAA.

Without radar, controllers could only allow about four arrivals an hour at those airports in poor visibility, which could trigger lengthy delays or flight diversions. They should be able to increase that to 10 or more, said Greg Dyer, a manager at the Longmont facility.

Colorado, which was concerned that delays at the airports were hurting the state's lucrative tourist business, paid $4.7 million to build the system. That is less than the cost of installing a single radar at one airport. The state and the FAA are hoping to expand the coverage to six more mountain airports.

"It was affordable and a pretty elegant solution for Colorado," said Travis Vallin, aviation chief at the state's Transportation Department.

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