Sunday, March 29, 2015

$20B project building highways in the sky using GPS



DENVER – Air traffic controllers across the country are in the middle of a $20 billion, 20-year modernization project to improve airline travel in a way most passengers will never even notice.

The Federal Aviation Administration's NextGen project uses GPS technology and better flight computers to more precisely track where planes are in the sky, allowing them to fly shorter, more direct routes while saving fuel and providing smoother, quieter landings for passengers.

The suite of NextGen technologies and procedural changes allow controllers to reduce the distances between planes as they take off, land and soar above America. Putting the planes closer together – we're still talking being miles apart, of course – frees up capacity in the congested skies, especially in cities with multiple airports like New York City and Washington, D.C.

"It's theoretically a perfect utilization of airspace," said Mike McKee, the noise abatement and NextGen coordinator at Denver International Airport, one of the nation's most technologically advanced airports. Because Denver's airport has so many runways and few homes nearby, FAA officials used it to help develop many of the NextGen techniques.

Not everyone likes the new system, however: Officials in Phoenix are threatening to sue the FAA over noise concerns because the new flight paths take more planes over a smaller number of homes, instead of distributing them more widely and reducing the impact.

FAA officials say the changes offer significant advantages for the overall public, in large part because GPS allows controllers to know exactly where a plane is at every moment. Radar gives a snapshot of locations every 12 seconds, which means controllers must keep the planes farther apart in the sky to ensure maneuvering room in case of an emergency.

At the Memphis International Airport, for instance, controllers and pilots using NextGen mean FedEx can land up to an extra nine planes an hour, saving the company $1.8 million a month. In Atlanta, the system means up to an extra 12 planes can depart each hour, saving fliers the equivalent of 1.3 years of waiting annually. And in Las Vegas, NextGen-capable planes shave 10 minutes off every landing by taking more direct routes, the FAA says.

In addition to saving time, the fuel savings add up quickly for airlines. In the skies above Washington, D.C., airplanes using NextGen techniques will save about $2.3 million in fuel per year and cut aircraft exhaust emissions by 7,300 metric tons, the FAA says. FAA officials see NextGen as a significant step in government efforts to cut greenhouse gas emissions caused by burning fossil fuels.

NextGen's next major milestone is the 2020 deadline for airlines to equip their planes with the technology necessary to use GPS-based navigation, instead of radar. The FAA is spending about $1 billion annually on the program. Several audits have criticized NextGen for its initially slow start and higher-than-predicted costs, but FAA Administrator Michael Huerta said the program is now on track, having spent about $5 billion so far.

"We're in a good place, deploying a whole lot of benefits around the country," Huerta said. "NextGen is happening now. We've done the hard work."

Not every airplane and airport can benefit from all aspects of NextGen. Airlines flying older planes, for instance, must install expensive flight computers and tracking systems that commonly come installed on newer Airbus and Boeing aircraft.

One place passengers may notice NextGen's improvements is during descents. Normally, air traffic controllers assign airplanes to descend a virtual set of stairs by slowing their engines to for a few seconds, accelerating again to maintain level flight for a few more miles, and then descending again. "It's the airplane equivalent of stop-and-go traffic," Huerta said. "It's incredibly inefficient."

With NextGen, the plane glides on a smooth path, engines reduced to idle, the route plotted by GPS and the flight computer. Most of the commercial airliners landing in Denver use that approach, which you can recognize if you're looking for it. Planes using that system in Phoenix save an average of 70 gallons of fuel each time they land on that low-power glide approach, the FAA says.

NextGen also allows airplanes to fly curved, instead of straight, paths, especially on takeoff and landing approaches. While planes often fly curved approaches, the GPS and flight computers can keep them on a tighter track, allowing more planes to fly through the same area simultaneously.

"The big thing for us as pilots is that they're repeatable and predicable flight paths," said Ron Renk, United Airline's chief technical pilot for navigation and flight operations technology. Renk, who flies Boeing 737s, said frequent fliers are usually the only ones who notice the low-power descents: "You occasionally get somebody who will come up and say, 'We were really quiet on that landing.' "

Not everyone loves NextGen. In Phoenix, some residents complain that the flight paths rolled out in September 2014 mean more planes flying more frequently over a narrower area, rather than distributing the takeoff noise more broadly. Phoenix officials met with the FAA to seek changes, although the agency was reluctant to make significant changes because the system works as a whole, according to city officials.

In Minneapolis, residents and city officials are also concerned about the narrower flight paths and more frequent flights. Minneapolis has tens of thousands of homes near the airport, and any changes impact residents significantly, City Councilman John Quincy said.

Huerta said the redesigned flight patterns are generally quieter, especially for landings, because the planes are essentially coasting in. But that's little consolation for people whose homes are suddenly beneath what's effectively a highway in the sky for airplanes taking off in waves in the morning and evening, Quincy said.

"One of the things we're trying to convey to the FAA is that there is not a cookie-cutter solution," Quincy said. "They're making some pretty dramatic changes. And some of those changes are for the good … (but) we'd like to have the noise distributed more fairly, because the concentration of flight paths ends up picking winners and losers.

Story, video and photos:  http://www.usatoday.com


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