Avoiding Close Calls in the Sky
A revolutionary air traffic control technology will give pilots an eagle's eye view of their plane and those around them, helping to avert mid-air collisions and saving airlines money.
With only 300 feet between them, a United Airlines Boeing 777, bound for Beijing with 251 passengers, and a tiny Cessna were too close for comfort. On Saturday, air traffic controllers at San Francisco International Airport had failed to note that the two planes were converging. With seconds to spare, a controller alerted the pilots and a crash was avoided.
Ironically, the Oakland Air Traffic Control Center, nearby, has firsthand experience of how this kind of foul-up can be eliminated. A revolution in air traffic control technology is under way, and the first part of it has been on trial at Oakland for some trans-Pacific flights, involving Boeing 747s flown by United.
The biggest change will be that, for the first time, pilots will see what controllers see—a picture of all the planes around them, as well as their own position in relation to those other planes.
The biggest change will be that, for the first time, pilots will see what controllers see—a picture of all the planes around them, as well as their own position in relation to those other planes. That will be a lot safer than relying on controllers to not only spot converging flight paths but to get on the radio and warn pilots, in situations where every second counts.
The new system is called NextGen. It uses the satellites of the Global Positioning System to send data simultaneously to the control towers and to the cockpits. With that one step, the pilot, instead of seeing the extremely limited view of the sky ahead, will have complete situational awareness, whatever the weather and density of traffic.
Airlines like this transformation not just because it will greatly improve safety but because it will save huge amounts of fuel, and therefore money. Once NextGen is fully deployed, pilots will be able to choose the most direct and economical routes, rather than be prisoners of the archaic “Highways in the Sky” system in use for many decades. The United trials at Oakland have already proved this, with the big jets making beeline approaches and gradual descents instead of joining wasteful holding patterns.
Why has this taken so long to achieve? The Federal Aviation Administration has a history of embarking on expensive upgrades to air traffic technology only to end up with systems that either don’t function well or are obsolete by the time they have worked through the bugs. With such enormous investments called for because of the sheer size and heavy traffic of U.S. air space, a federal agency isn’t exactly the culture one would choose to press ahead with innovations as vital and demanding of management skills as this. But since we are stuck with the FAA, they set the pace of change.
Saturday’s emergency leaves two messages: One, that the sooner the NextGen systems are in place the better. And two, there are no near misses—they are near hits.