New Airline Navigation System Is Displayed
A friend sent this to me by email. Seems we have interesting navigational enhancements coming up.
Kester
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WASHINGTON, Dec. 20 - The jet approaching Reagan National Airport followed the complicated turns required for the prescribed route over the Potomac River, banking sharply left and right as it descended smoothly toward Runway 19. But the two pilots never touched the controls. The plane was being guided by the autopilot, which was taking its cues in three dimensions, from satellites in orbit.
Until now, an autopilot could only fly a plane in a straight line or around a gentle curve. But the one shown off Tuesday by the Federal Aviation Administration was following a path as sinuous as the river beneath, a route that planes use to control noise when they approach the airport from the north. The problem is that pilots can follow a river only when they can see it, and when the clouds descend, National is sometimes closed to arrivals.
But now at National, and a handful of other airports around the country, autopilots can fly planes safely over terrain that no one on board can see, including around mountains. Use of the new system is expected to cut the number of times that airplanes have to divert because of weather, interruptions that cost an airline tens of thousands of dollars in refueling costs and schedule disruptions.
"This is a game-changer," Marion Blakey, administrator of the F.A.A., said in a presentation in a hangar.
The system will be available for use at Kennedy International Airport in New York beginning early next year, and will be ready at airports in Houston and Chicago in 2006.
The new system, called Required Navigation Performance, can be used on an airliner with a receiver for the Global Positioning Satellite system, and a flight management computer and an autopilot, something that most of them already have. Airlines must also train their crews to use the system.
The aviation agency figures that the government costs are tiny, about $20,000 to develop each approach. (This does not count the multibillion- dollar cost of the Global Positioning System.) There is no hardware on the ground.
System accuracy varies, but the one shown off Tuesday at National Airport keeps the plane in a path 1,800 feet wide. An airplane following the route can descend safely to 475 feet, at which point the pilot must either be able to see the runway or must give up and climb.
Using conventional navigation techniques, the plane must stay higher, about 720 feet over the ground, which in bad weather is far more likely to be in the clouds, meaning an aborted approach.
When the system is at Kennedy, officials believe it will have major advantages for La Guardia Airport as well.
The new system will allow a curved approach to Runway 13 Left at Kennedy, so planes can come up over the Canarsie section of Brooklyn and make a right turn to land, as they do when the weather is good. But when the weather is bad, they use an instrument landing system that requires them to approach in a straight line, and taking that route, across Manhattan and Brooklyn, interferes with traffic approaching La Guardia's Runway 4 from the southwest; in fact, La Guardia usually has to close that runway.
In New York, flying to Runway 13 Left at Kennedy has meant that the clouds had to be above 800 feet. But using the new system, beginning early next year, pilots will be able to descend to 400 feet before they can see the runway, said Nicholas A. Sabatini, the associate administrator for safety at the aviation agency. He estimated that using the new system would cut air traffic delays in New York on scores of days every year by "de-conflicting" runways like 13 Left at Kennedy and 4 at La Guardia.
