Friendlier skies for airlines, airports
New, more precise navigation systems will help pilots save time, fuel and may calm runway abutters
With a big new boost promised from the nation's busiest airline, Southwest Airlines Co. , a long-brewing revolution in US air traffic control is finally poised for takeoff.
It's a change that could make everyone connected with the aviation business happier: passengers, pilots, control-tower crews, airline shareholders, and even airport neighbors.
Comprising an array of technologies dubbed "performance-based navigation," the upgrade is sometimes compared to drawing the equivalent of highway stripes across the airspace around busy US airports. With cockpit software upgrades and better use of navigation systems , planes will be flying increasingly precise and direct routes that make far more efficient use of available air.
For passengers and pilots, it can mean fewer delays and more direct routes that get them from one place to another faster, and safe landings in rain and fog conditions that now shut out arriving flights. For airlines, it means less fuel consumption. American Airlines and Delta Air Lines already report sav ing tens of millions of dollars annually from initial rollouts of the changes at their Dallas and Atlanta hubs over the last three years.
For air traffic controllers with the ultra-stressful job of guiding planes into and out of airports, complicated turn-by-turn radio instructions can be replaced with a single order to follow a specific takeoff or arrival pattern programmed into the cockpit computer, like a football quarterback telling a receiver what pattern to run.
And for residents of communities plagued by jet noise, like East Boston, Hull, and Winthrop, the system promises to keep planes inside much more tightly drawn takeoff and arrival paths that can be drawn to reduce overall noise levels.
"It's almost as if we painted lines in the sky, and every time we could fly precisely on these lines," Joe Kolshak , Delta's executive vice president of operations, said in an interview. "What that means for capacity, for safety, for fuel consumption, it's huge."
Two major elements of the ongoing navigation upgrade are called RNAV, for area navigation, and RNP, for required navigation performance. They enhance, and in some deployments supplant, existing ground-based radio navigation beacons by tapping in to the US Air Force's global positioning system satellite network. Rolling out the technology requires cooperation between airlines and the Federal Aviation Administration -- airlines to upgrade their planes' navigation systems, the FAA to approve special new arrival approaches and departure lanes and train tower controllers in managing them.
Over the last month, there has been a flurry of announcements about plans to expand the technologies. Southwest Airlines -- the biggest US carrier ranked by passenger volume and flight operations -- confirmed it will upgrade all 490 of its Boeing 737s for RNP operations by late next year. Southwest has hired a Seattle-area navigation software company, Naverus Inc. , to chart new approaches for cockpit navigation computers into Bradley International Airport in Windsor Locks, Conn., Manchester Boston Regional Airport in New Hampshire, T.F. Green State Airport outside Providence, and the 60 other US airports where Southwest flies.
American Airlines said it will spend $100 million to add area navigation capabilities to its 300 MD-80 jets, the main workhorses of its 672-jet fleet. The Federal Aviation Administration, which has approved 155 RNAV special arrival and departure paths at Logan and 37 other US airports, said it will approve another 42 by September.
Alaska Airlines reported that thanks to enhanced navigation capabilities, 980 of its flights were saved last year from mandatory diversions during weather conditions, like low clouds or thick fog, that would have prevented standard-technology planes from landing. With enhanced navigation, federal safety laws can allow pilots to land with less visibility through the cockpit windshield.
Among many other effects, the navigation changes are allowing airlines such as Delta to begin experimenting with what are called "continuous descent approaches" to airports. For a pilot, it's roughly like putting the jet in lowest gear at 35,000 feet and coasting the last few hundred miles in to the airport. Early results indicate Delta could save 13 million gallons of jet fuel annually just on flights coming in to its Hartsfield Jackson International Airport hub in Atlanta, potentially more than $30 million.
"It's a huge improvement, and it is definitely more efficient for the national airspace system," said Vince S. Polk , an Atlanta tower controller who is chairman of the safety committee for the National Air Traffic Controllers Association. Polk said that "as with any other new tool, there are kinks to be worked out," like how to smoothly handle a flight whose departure runway gets changed after its departure path has been loaded into the jet's navigation computer. Still, Polk said, "Safetywise, right now I feel it's the best thing to do."
Currently, few of the 1,000 to 1,100 daily flights arriving at and departing from Logan take advantage of the new navigation systems, according to Steve Kelley , an FAA "airspace redesign" manager. The systems make a dramatically bigger difference when most or all jets using an airport are flying enhanced paths, because if only a small minority are, they still have to be given the wide clearances mandated for planes using less precise navigation.
As part of an ongoing effort to reduce jet noise around Greater Boston and spread it more evenly, the FAA wants to get more airlines using more RNAV and RNP flight routes, including having more planes at higher, less noisy altitudes as they cross over the harbor shoreline and across populated areas, Kelley said.
In time, the technology could allow Logan to exceed its current rough cap of 120 takeoffs and landings per hour by bunching more planes closer together. But, Kelley said, "It's not about increasing capacity. It's about improving predictability [of flight paths] and giving noise relief. It's not about a capacity gain for us."
Peter J. Howe can be reached at howe@globe.com. 