WASHINGTON, Sept. 4 — At Hartsfield-Jackson Atlanta International Airport, Delta Air Lines said its jets take off an average of 10 minutes after pushing back from the gate — three minutes faster than in previous years.

Using new technology, planes take off following a narrow route, so that that jets right behind them taking different routes do not have to wait as long. That makes the system move a bit faster.

“The pilots say, ‘Wow, this is kind of neat,’ ” said Joseph C. Kolshak, executive vice president for operations at Delta.

Delta, and also Alaska Airlines and U.P.S., is demonstrating pieces of the possible future of the nation’s air traffic system, hinting at what aviation might be like — if the airlines and the federal government can get the details worked out.

All three airlines use refinements based on the constellation of G.P.S., or global positioning system, satellites. Many of these save at most a few minutes. But in a crowded system plagued by delays, that may be enough to help smooth out bottlenecks.

The carriers’ use of satellite navigation and other tools and techniques represents a step toward replacing a 50-year-old system of radar and radio beacons.

In the process, they are pulling along a slow-moving government agency, the Federal Aviation Administration, that is eager for better air traffic control systems but short on money and the authority to put changes in place.

It is a revolution in technology, but also in politics. Previously, the F.A.A. usually bought new systems on the ground and told airlines to equip themselves to use them; now the airlines are taking the initiative to outfit their planes, with safety regulation from the F.A.A.

Airlines are even developing their own approach patterns for airports, which has almost always been a government job.

U.P.S. Airlines, working with Aviation Communications and Surveillance Systems, based in Phoenix, is developing a landing pattern based on separating planes by time, not distance, so they land at the briefest safe interval.

“We’re going to create the future, because we think we know where it’s going to go,” said Karen Lee, director of operations at U.P.S. This is in contrast to the traditional way of doing business, typified by “the F.A.A. tells us what the roadmap is,” she said, then “we’ll start building the stuff to do it.”

This is not quite do-it-yourself air traffic control, because everything requires F.A.A. analysis and approval.

But the agency is encouraging airlines to innovate, and is getting itself out of the picture, in many ways. For example, last Thursday it awarded a contract to a team led by the Corporation">ITT Corporation, worth $207 million initially and possibly up to $1.8 billion, to build and operate a national network of radio receivers to accept signals from airplanes in flight.

Each plane would give its position as determined by G.P.S. The ITT contract is part of a system that would process that data to allow controllers and pilots in flight to see a display showing where all the planes are.

Another big step for the agency, which it hopes to take this year, is to publish a proposed rule giving the schedule for when airplanes will have to be equipped for satellite navigation and surveillance.

No one knows how much this will cut delays and improve capacity. But there are glimpses. One is in Juneau, Alaska.

For years, airplanes could not safely find the runway there, nestled between mountains, unless clouds were at least 1,000 feet above the ground and visibility was more than two miles.

And if there were clouds, there was only one way out, to the west, with a quick U-turn, which could be frustrating for travelers.

To assure that the plane could accomplish that maneuver under worst-case conditions — an engine failure on takeoff — Alaska Airlines often had to leave passengers or freight behind at the airport.

Today, Alaska Airlines’ planes land there as long as clouds are 337 feet above the surface and in visibility down to one mile. And they can take off in either direction. Of the approximately 3,600 flights the airline operated in and out of Juneau last year, 754 could not have been tried in years past.

“It’s a thing of beauty,” said Kevin Finan, acting vice president for flight operations at Alaska Airlines.

The more reliable operations happened because of a system developed largely by the airline. Through a combination of G.P.S., traditional navigation aids and instruments on board that give the plane’s position by measuring each turn, Alaska Airlines’ Boeing 737s know their position within 600 feet, the airline equivalent of the head of a pin.

In contrast, the older system required pilots to draw a mental map of the plane’s position, using compass cards and a display of how far the plane was from some land-based radio beacon, and a paper chart showing the mountains in the area.

Now the planes have a map that shows the mountains, the weather and the plane’s position.

A satellite-based system that allowed airplanes to be limited to narrower routes would help in New York, experts say, where departure routes from Kennedy, La Guardia and Newark Liberty airports are already sharply limited because the three fields are so close to one another. With greater assurance that the planes would follow a precise path, planners could increase the number of routes.

Perhaps the most ambitious effort is being carried out by U.P.S. Airlines at its hub in Louisville, Ky.

The airline does not fly passengers. But it is even more eager to assure that packages make their connections, since the next flight may be 24 hours away. A single plane can carry 10,000 packages, potentially infuriating just as many shippers and recipients if the plane is delayed.

U.P.S.’s problem, like the problem of many passenger carriers, is that it needs to land many planes in a hurry, and then send them on their way.

Louisville has parallel runways, and in theory it can accept 60 planes an hour, one every two minutes on each strip of concrete.

But an observer with a stopwatch can tell that instead of a plane arriving every 120 seconds, said Ms. Lee of U.P.S., the planes would be spaced apart by 150 to 180 seconds. There is a lot of free time in useless segments between flights.

U.P.S.’s solution was to line up airplanes in the sky, 100 or 150 miles out, spaced not by distance but by seconds. Airplanes have almost always been controlled in altitude, latitude and longitude, but not in time. Doing so requires a fundamental change in air traffic control.

In the cockpit of an 18-year-old Boeing 757, Christian Kost, a technology manager at U.P.S., showed off the piece of equipment that will allow the control of timing: a flat-panel screen about the size of a laptop screen that shows the pilots all the planes in the area.

Soon the system will show the precise speed that the 757 would have to fly to maintain that 120-second interval, a speed that will vary as the line of planes in the sky slows and compresses, like cars leaving a highway and entering an exit ramp.

That will allow the planes to separate themselves, rather than having an air traffic controller issue instructions to speed up or slow down. And a controller, looking at radar, will never space the planes as precisely as the pilots can, experts say.

Spaced correctly, the airplanes can descend in a straight line, with their throttles near idle. In the current system, controllers get them lined up by low-altitude maneuvering.

Ms. Lee, who flies a Boeing 747, described getting to within 40 miles of the runway at Louisville, and then flying as far as 80 miles to land. At 9,000 feet, she said, controllers would order her to slow her plane so much that she had to deploy the landing flaps, which meant setting the throttles higher and burning more fuel.

“It drove me crazy,” she said.

The straight-in approach, descending at a constant angle, saves 50 to 100 gallons of fuel for each flight.

U.P.S. can experiment because it flies when other airlines are asleep. But the technique would not work well at most airports, company officials say, until everyone was equipped for it.

The same is true of the tighter navigation procedures used by Delta and Alaska Airlines. The F.A.A. is preparing a rule that would require such equipment and the training that goes with it. The rule might be out for several months of public comment by the end of the year, but it would have an effective date months or years after that.

And the F.A.A. has problems ordering new equipment, because in the past, it had pushed the airlines to equip themselves for a variety of technologies that the agency later dropped. The agency hopes that demonstrations by the airlines will build a consensus for modernization.

“We know where we need to go, but with an air traffic control system designed in the 1960s, we just can’t get there from here,” said Marion C. Blakey, the F.A.A. administrator, testifying before the House Ways and Means committee on Aug. 1.

The new concept would require diverse parties to agree on standards, procedures and extensive investments.

“The transition path is murky,” said George L. Donohue, a former associate administrator at the F.A.A. who was responsible for research and acquisitions and is now the head of the Air Transportation Laboratory at George Mason University.

For Alaska Airlines, Delta and U.P.S., the push for better air traffic control is not so much a matter of policy as it is a business case. And that is probably the only way that other airlines will agree to equip their airplanes — at a cost that can run into the hundreds of thousands of dollars for each plane, depending on its age — for a system that will not achieve its potential until all planes are equipped.

But if carriers like U.P.S. can demonstrate a 10 or 15 percent improvement in the capacity of the runway, “everybody else is going to want to have the same thing,” Ms. Lee said.