Untangling The Traffic Jam In The Air
Lost in all the hand-wringing over how to fix the U.S. skies is one simple fact: The technology already exists to make flying simpler, safer, and more efficient. It's already in use now at some airports. United Parcel Service (UPS ) and Fedex (FDX ) use state-of-the-art satellite navigation to guide planes to their big consolidation centers. Australia and China are also streaming past the U.S. with next-generation flight-control systems.
Planes in the air in the U.S. today rely on an archipelago of control centers, radar towers, and radio beacons that dot the continent. Once the aircraft are beyond the range of runway control towers, they are tracked by a series of facilities along their route. To locate a plane, radar dishes sweep the skies about every five seconds—though it can take 10 seconds or longer. Near airports, three such towers may be needed to get a precise fix on a single plane. To confirm critical details—the plane's identity, destination, position, and speed—controllers and pilots chatter back and forth.
Today's system is reliable and safe. But it's imprecise, and radar towers are costly to build and maintain. The FAA's sweeping NextGen program would shutter at least one third of its 500 or so air traffic facilities while migrating to a better system. The cornerstone is called ADS-B, for automatic dependent surveillance-broadcast, which gives every plane its own digital brain and voice. Using GPS, the plane constantly transmits its position, speed, direction, and destination to other planes and ground control. The diagram to the right shows how this works.
By Adam Aston