The $35 billion plan would replace the current radar system with the kind of GPS technology that has become commonplace in cars and cellphones. Supporters say it would triple air traffic capacity, reduce delays by at least half, improve safety and curb greenhouse gas emissions.
An Associated Press analysis of federal and industry data found that if the new system were already in place, airlines could have saved more than $5 billion in fuel this year alone.
But funding delays and the complexities of the switchover have kept the project grounded. The government does not expect to have it up and running until the early 2020s, and without a major commitment, supporters warn that even that goal might be not be attainable.
"The United States has been to the moon and back. I think the public deserves that same level of effort for our national airspace system," Robert Sturgell, the acting administrator of the Federal Aviation Administration, said in a recent interview.
The planned satellite-driven network, dubbed NextGen, would save fuel by ditching radar technology that is more than 50 years old and enabling GPS-equipped planes to fly the shortest route between two points: a straight line.
NextGen could save airlines at least 3.3 billion gallons of fuel a year — or more than $10 billion annually by 2025, based on today's fuel prices, according to FAA projections obtained by The Associated Press.
Currently, jetliners move in single-file lines along narrow highways in the sky marked by radio beacons. Many of the routes gently zigzag from one beacon to the next, sometimes forcing cross-country flights to follow sweeping arcs and waste hundreds of gallons of fuel.
It's "the equivalent of using an electric typewriter when others are using computers," said David Castelveter, a spokesman for the Air Transportation Association. "It's a huge, huge drag on productivity."
Some private and commercial aircraft already are equipped with GPS devices that pilots use to determine their position, but the NextGen system would dramatically expand use of the technology by creating a nationwide GPS network for air traffic.
Building the network involves gradually putting together the new system while still relying on radar for day-to-day operations.
Gerald Dillingham, director of civil aviation issues at the U.S. Government Accountability Office, likened the process "to changing a tire on a car that's going 60 miles an hour."
Hank Krakowski, the FAA's head of the air traffic system, called it "one of the largest project management challenges the federal government has had since we put somebody on the moon."
Airports also have to make improvements to accommodate the expected increase in air traffic.
U.S. airlines have struggled in recent years, in part because of rising fuel prices. Ten airlines have shut down and others are facing bankruptcy. Their financial troubles mean less-frequent flights and fewer amenities for air travelers, who must pay more for tickets, luggage, drinks — even pillows.
A report on NextGen released last month by the Government Accountability Office said major problems remained, including a lack of detail about just how the system would work and a shortage of the kind of highly skilled managers needed to see the project through.
Critics have said the Bush administration, while expressing support for a satellite-based system, never pushed hard enough for it.
"The next president needs to make the NextGen initiative a national priority and ensure that it is given the resources, management attention and sense of urgency that it warrants," said Rep. Bart Gordon, a Democrat from Tennessee and chairman of the House Science and Technology Committee.
Airlines are expected to contribute $15 billion toward the $35 billion project, and they must equip their fleets with GPS at a cost of more than $200,000 per plane.
But most carriers — which are otherwise enthusiastic about NextGen — are reluctant to retrofit planes years, maybe decades, before the satellite network is fully operational.
"It's like you buying a new car and the dealer saying, 'How would you like to buy this nifty GPS technology — but it won't be available in your area for years,'" Castelveter said.
The NextGen system could offer airlines a 10% savings in fuel costs per year. If the network were in place today, it would essentially pay for itself in just seven years.
GPS is already used in many parts of the aviation world. Many European countries, China and even Mongolia have established some GPS networks or plan to do so soon.
At least one major U.S. carrier, Southwest Airlines, says it's investing $175 million to equip 500 planes with GPS within a few years. That will allow pilots to fly more efficiently even before the full NextGen system is in place, including quicker landings that burn less fuel.
Getting each of its planes on the ground just one minute faster, Southwest says, would save $25 million in fuel a year.
The airline could wait until the new system is up and running, "but we're pouring gas down the drain," said Dan Gerrity, CEO of Naverus Inc., which is helping Southwest implement its GPS plans.
Cargo carrier UPS has also installed GPS gear on hundreds of aircraft for use at its Louisville, hub, saying the technology will save nearly a million gallons of fuel a year, as well as reduce noise and emissions by around 30%.
NextGen would also help airliners fly, land and takeoff closer together, minimizing delays. Even though the technology would allow more planes into the sky, the FAA and pilots agree that the technology would actually reduce the risk of accidents such as midair collisions and runway incursions.
NextGen would for the first time let flight crews view precisely where other aircraft are using a cockpit monitor. The current radar system takes more than 10 seconds to scan an area, so controllers keep aircraft separated by several miles as a precaution.
Most pilots see NextGen as the best hope for keeping flights on time. Rory Kay of the Air Line Pilots Association said the improved technology could also help relieve pilot fatigue by cutting the time planes wait on the ground.
Passenger groups generally support the project, even though they expect airlines to pass some costs onto customers.
"But we think it'll all be worth it in the long run," said David Stempler, president of the Air Travelers Association. "The alternatives look pretty bleak to us."
To the FAA's consternation, Congress has failed to pass a bill giving the agency permission to dip into the nation's aviation trust fund to spend nearly $6 billion on NextGen over the next five years.
Robert Poole, an aviation expert with the free market-oriented Reason Foundation, said some legislators are reluctant to vote for a satellite system that would make eliminate hundreds of jobs at radar stations in their districts.
Meanwhile, the air traffic controllers union, which is often at odds with FAA brass over labor issues, accuses the agency of seeing the whiz-bang satellite technology as a cure-all for aviation problems.
It says some of the millions of dollars earmarked for NextGen would be better spent maintaining the current system, citing an FAA computer glitch in August that delayed 650 flights at airports from Orlando to Chicago.
It's become fashionable, he added, to blame the radar system for aviation ills while ignoring other factors — such as overbooked flights and a lack of suitable airports and runways.
"GPS might be great to put in your car, too, but it's not going to get you to work any faster unless they open up another lane on the highway. And it's the same in the air," said Doug Church of the National Air Traffic Controllers Association.
Poole said the FAA has a track record of proposing dazzling-sounding projects, then failing to deliver.
He cites an FAA initiative called STARS, which was launched a decade ago to give controllers advanced, multicolored radar screens. The project missed deadlines, went hundreds of millions of dollars over budget and had to be scaled down.
Poole doesn't doubt NextGen's potential, but he's pessimistic about the prospects for rapid progress.
"I just think it's very unlikely to be done in anything like the time frame and the budget now projected," he said. "And that will be a tragedy for aviation."