Satellite-based navigation promises to increase capacity while enhancing safety
Almost 2,300 years ago, the Greek mathematician Euclid stated that the shortest distance between two points is a straight line.
While that fact isn’t lost on the U.S. airline industry, the reality is that aircraft don’t fly in a straight line. Instead, they fly in the direction of one ground-based navigation aid and then another, literally connecting the dots as they methodically zigzag their way across the sky to their final destination.
But all that’s about to change with the introduction of new performance standards, which will one day allow pilots to rely instead on a combination of onboard- and satellite-based navigation aids to fly in a much straighter line from Point A to Point B.
Area navigation, or RNAV, will allow for the more efficient use of airspace, increasing the capacity of the air traffic system while reducing flight delays and decreasing fuel consumption. And because of the pinpoint accuracy provided by RNAV systems, it also will improve the margin of safety of air travel.
In talking about how RNAV increases capacity, can you provide a real-life example of the benefit?
Barimo: Dallas-Forth Worth (DFW) is a good illustration. RNAV will increase the airport’s throughput of aircraft by about 14 percent. That means DFW will be able to absorb all its projected passenger and operational growth over the next 10 years.
The New York area provides another good example of the benefit of performance-based navigation. Newark and LaGuardia have approaches to runways constrained by adjacent traffic flows and airspace. By using onboard- and satellite-based navigation systems, approaches can be narrowed and airspace conflicts avoided. The result is a smoother and more efficient flow of aircraft in and out of the region.
Why is capacity growth so critical?
Barimo: It’s critical because current projections show that operations at the nation’s 35 largest airports will grow by approximately 70 percent over the next 15 years. In raw numbers, we’re talking about 820 million passenger trips. Plus general and business aviation is growing. Add it all up and you have an air traffic system bursting at the seams.
Who is driving the push toward performance-based navigation and RNAV?
Barimo: That’s another great aspect of this – virtually the entire industry is behind it. The FAA is obviously taking the lead role, but it's being supported by the airlines, labor unions, airports, aircraft and avionics manufacturers, business and general aviation, research organizations, the Department of Defense and others.
Of the fleets of the major U.S. commercial carriers, what percentage of aircraft are RNAV capable today?
Barimo: About two-thirds. But if you look at the aircraft serving our busiest airports, the number climbs to about 80 percent. Given current fleet upgrade and acquisition projections, all of our major carriers should be 100 percent RNAV capable within a few years.
To what degree is RNAV being used now and how long before it’s widespread among commercial carriers?
Barimo: Most of the initial applications of RNAV are going to be in the terminal area surrounding the busiest airports in the country. Arrival and departure procedures will be redesigned for more efficient operations with fewer instructions from air traffic controllers.
Currently, RNAV procedures are in place at Atlanta, Las Vegas, Philadelphia and Washington Dulles, with more airports to follow. In addition RNAV routes will also be implemented in the enroute airspace, between airport terminal areas. These routes already operate up and down the West Coast for aircraft that meet the requirements.
The FAA, with input from the airline industry and others, has published a “Roadmap for Performance-based Navigation” that calls for implementation of RNAV in three phases. The first phase runs through 2006. The second runs through 2012 and will produce the most dramatic change as RNAV becomes the primary means of navigation throughout the nation. The final phase runs through 2020.
You mentioned Atlanta. What specific benefits can we expect to see at that particular airport for example?
Barimo: We expect to see significant benefits there. That's because Hartsfield-Jackson International is the world's busiest airport with an average of 1,350 daily IFR departures. And about 90 percent of those departures can take advantage of these procedures.
Atlanta's largest carrier, Delta, has already said that it expects to realize annual cost savings of up to $30 million resulting from a combination of factors, including a more efficient use of airspace, fewer delays for our customers and less fuel burn.
Will ground-based aids be completely done away with by 2020?
Barimo: No. The number of ground based navigation aids will gradually be reduced to a point where there is a remaining network to provide back-up navigation services.
It’s probably fair to say that some aircraft operators have a long way to go before they are equipped to use RNAV. So how, during the coming years, do you make sure all airspace users are being served adequately?
Barimo: The FAA recognizes that there will be a significant period of time in which they will have a mixed-capability environment. Aircraft without RNAV will be served, as they always have, by conventional procedures and radar vectoring. The mixed environment presents challenges, but we believe they can be safely and economically managed.
Related Links
FAA Final Draft of the Update to the Roadmap for Performance-based Navigation
Before and after flight patterns from Atlanta Hartsfield Airport (ATL)