ADS-B Technologies: changing the face of aviation safety and surveillance.

• Author: Johnston, Ross
• Position: Special section: Transportation

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Skip Nelson, the founder of ADS-B Technologies, reclines at his desk, his hands folded beneath his chin. He has that old grizzled Alaska pilot look. A gray thick mustache sits beneath his nose like those in countless pictures of Alaska Bush pilots. However, his profile belies his experience as a NASA astronaut candidate and as a US Navy Fighter Pilot. It is his Bush pilot experience, though, that has inspired his company's pioneering work in space-based aviation surveillance and tracking.

ADS-B Technologies has developed the world's only working prototype that allows equipped planes to be tracked every second no matter where they are. It seems surprising that a small Alaska company will change the face of aviation safety and surveillance. But, when chatting with Nelson, the president of ADS-B Technologies, it is a natural conclusion due to the closing of a long dark chapter in Alaska's aviation accident history.

Back in the 1990s, Alaska had by far, by a factor four or five, the worst aviation accident record rate in North America. There was a major aviation accident every three days and a pilot died every nine days on average.

Under Alaska Senator Stevens' urging, the aviation industry and the Federal Aviation Administration came together in the late 1990s and formed a group called the Aviation Coordination Council. They tried regulation and they tried safety training, but nothing worked. Nelson relates that they finally figured that there had to be a bouquet of technologies that would lower the accident rate.

Capstone & ADS-B

The council came up with a program called Capstone, and the core of Capstone was a new air traffic control technology called "Automatic Dependent Surveillance Broadcast" or ADS-B. Unlike radar, which bounces energy off of an airplane and interprets the position on the return, in ADS-B the aircraft becomes an active participant. It gets its position from a GPS constellation, adds a lot of other data including the type of airplane, who it belongs to, its mission and its actual perceived heading out altitude airspeed. Then, every second it transmits its information to the world.

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Ground stations pick up the signal and put it right on the surveillance screens of the control towers. This information can also be received by another airplane equipped with "ADS-B In," and allowing airplanes to better coordinate within their shared airspace. ADS-B was deployed in most planes in...