How intelligent flight paths can reduce delays, noise, carbon emissions

Our air traffic control system is outdated, inefficient and ill-equipped to handle the increasingly congested air space, resulting in delays and higher costs to passengers, according to GE Aviation. They say navigation is the answer.

Complaining about airport body scanners might have been the complaint du jour this Thanksgiving weekend, but what about the downsides of commercial aviation that we’ve been groaning about for years—such as delayed arrivals and departures?

GE Aviation is one of the companies working with the Federal Aviation Administration in the agency’s overhaul of the national air space system, called NextGen. The idea behind NextGen is that tracking air traffic more precisely and efficiently will save fuel, reduce noise and pollution, cut down on delays an save the airlines billions of dollars. In August, American Airlines completed the first flight using GE’s new system, with Required Navigation Performance (RNP) technology (see video below).

I recently spoke to Steve Fulton, a GE Aviation technical fellow and former Alaska Airlines captain. Fulton, co-founder of Naverus (now part of GE Aviation) explained how this new “highway in the sky” can reduce carbon emissions, cut down on noise and make our flight arrivals and departures as dependable as the European train network.

What are some of the inefficiencies of today’s air traffic control system?

The air traffic control system we have today is a good system in that it’s safe, but it’s been around for quite some time, and it’s been grown up around some technology that has moved on. We need to update the operation and transition to a more modern air space.

For example, we’re navigating airplanes along airways that are defined by navigation beacons on the ground. But [a more modern] navigation infrastructure is now possible and is in fact on board the airplanes.

Imagine you go to a concert or a fair and you’re parking in a field, and you’re following a guy with an orange flag with no lines for the cars, and everyone ends up parking in a haphazard way. Compare that to a shopping center parking lot, where you have painted lanes, and your parking stalls are all defined.

If you take a 24-hour period where airplanes track over the ground, in three dimensions, there’s a high level of variation between one plane and another. The air traffic controller is providing directions. The navigation piece is the equivalent of the painted lines. When we have that type of operation, we’re able to have more precise timing—so our planes can come in as precisely as the trains in Europe.

The beacons that are used today—where are they located, and why are they so ineffective?

You could have up to 260 miles between beacons. They are around airports. They look like an upside down ice cream cone. I’m told that some of these are located where bonfires were once located, where air mail was delivered in the biplanes. Navigation structure at night was all bonfires. So they were lined along the routes between Chicago and Portland, for example. We’re talking about legacy infrastructure here, that’s been built up over decades. The operation of this air space has become quite complex.

Do most of our planes have GPS?

What may be surprising is that even though we have GPS units in our automobiles and even on our smart phones, the GPS on our airplanes is nowhere near equipped; and those that are equipped, we haven’t taken full advantage of their capabilities. [When we are able to do so] we will be able to navigate in a precise manner, and we will no longer have to fly to these ground beacons. The planes can fly in accordance to what these routes are.

At the same time that we have more lateral flexibility, we have the ability to fly the plane vertically in a more optimal way—with the least amount of engine power. When we want to come down and land, the ideal way is to have the plane do a continuous--or gliding—descent. So we combine the new lateral capability, and the path is vertically aligned, which means low noise and low fuel burn.

The airlines are businesses, and you spend money as investment for some return. NexGen is a satellite-based air traffic system. We’re setting up an environment so that those investments in GPS systems aboard airplanes will provide that return that the airlines need.

All this began in Alaska in the 1990s. We had an opportunity there to take a GPS system that was really new, and by 1995 we did the flight trials, and by 1996 we were flying with the first of these new navigation procedures. In that instance, the concern was that we navigate precisely through these mountain canyons in Juneau. Now, we’re taking that application and we’re deploying it as part of this air traffic system where the obstacles aren’t the mountains of Juneau but the air space, the noise, the other airports and air traffic operations.

Tell me about what you’re calling the “highway in the sky.”

A very precise, very flexible high performance path that allows the plane to move in a way that’s very organized. It’s the “painted lane,” so there’s no variance. Every plane flies the same trajectory; they are positioned precisely where the plane should be flying. In New York, for example, now we don’t have to fly all the way past LaGuardia to Hartford, Connecticut, before we turn around to capture the approach stream, where all the planes are being lined up in an arbitrary fashion.

So now we can come in more efficiently, just as though there was no traffic. We don’t do that today because we’re still managing the traffic with some pretty simple tools—the equivalent of the traffic director with the flag in the open field.

How is this being implemented today?

When I left Alaska Airlines in 2003, I was one of co-founders of Naverus--now GE Performance-based Navigation Services. We had invented this at Alaska and took it around the world. Of course Alaska is a low-traffic area with unique operating conditions. Then we tried it at higher traffic areas. So we worked through those problems and have gained a lot of experience, and we’re working with the FAA to bring that experience to the U.S.

In effort to work with the FAA, in August we flew a 737 from Dallas to Hartford. But more than a technical story, it’s a policy story. We’ve worked with the FAA to develop a process. The objective is to allow some commercial companies like GE to offer our resources, and that was the first time that that had been done and fully approved by the FAA, putting the procedure into the air space for public use.

What was involved for the carrier?

The airplane was already equipped. American has already been a full participant in getting their pilots trained. This was a normal passenger flight, and there wasn’t any unique preparation on the airplane side. It’s just a matter of programming the airplane’s computer.

What are the benefits?

There’s an environmental and economic benefit in the reduction of fuel burn—a total of 5 to 15 percent for a typical narrow body operation in the U.S. We can reduce noise in the order of 30 percent for a given point on the ground near the airport. And as we continue to gain experience, we’re seeing we can improve the capacity of the air space between 3 and 10 percent.

The progression we see—we have to continue to operate in the existing air space while we transition to the new operation. It is quite complex. A big part of it is building awareness with the different stakeholders. We’re working in incremental steps and bringing the work groups along so there’s a good facilitation of transition from the old way--an active, hands-on controlling activity—to an operation that’s more managed. Ideally the airplanes operate in a more strategic way and only intervene when necessary.

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