Explaining the Air Traffic Breakdown

The major failure of air-traffic control yesterday was yet another sign that our outdated radar-based system needs to be replaced with a sleek new satellite-based one, right? That’s the logical progression of much of the coverage out there.

The reality is that, yes, the system needs to be replaced. But yesterday’s failure was a high-tech one that could afflict a system based on satellites, too.

The problem wasn’t directly related to radar, but with the National Airspace Data Interchange Network, a system for processing flight plans and information for all flights in the country. It failed in both of its locations: Salt Lake City and Atlanta. This meant that automated regional FAA systems couldn’t process flight information. As a result, controllers had to enter information manually. This caused delays that rippled across the country. “A satellite-based system would have had the same problem,” R. John Hansman, an MIT aerospace and air traffic control expert, wrote to me this afternoon.

The Federal Aviation Administration hopes to roll out a Global Positioning System-based control system, called Next Generation or NextGen, in stages. By 2020 most planes will carry a cockpit gadget that continuously broadcasts the planes’ GPS-derived location, altitude, and speed to ground controllers. In later years, the system will extend so that this information is picked up by other planes, too, so that pilots can gain more control over their routing and spacing. As they beam their position information to one another they’ll be able, to some extent, to self-navigate. However, there will always be an FAA air-traffic system keeping track. It’s unlikely that pilots will ever be permitted to make all takeoff, routing, and landing decisions entirely by themselves in the event of failures of national air-traffic computers, as happened yesterday.