Required Navigation Performance started out in 1996 as a way for carriers to access mountainous airports safely. Now Southwest Airlines is about to use RNP to cut fuel burn and emissions while flying into all 65 airports it serves in the U.S.

To exploit these procedures, aircraft must use GPS and onboard monitoring equipment to transit a narrowly defined airspace corridor.

In a move similar to Southwest's, Australia plans to have a "nationally linked RNP network" deployed by the end of 2010. Qantas and Naverus - a Kent, Wash.-based company that develops RNP paths for airlines - have already instituted such procedures at 15 airports, and Airservices Australia is leading the effort to add 15 more airports across the continent. Melbourne will begin using RNP next year and Sydney by the end of 2010, says Peter Curran, the manager of national ATC capability for Airservices Australia. (Terrain is an issue at only a few of these airports.)

The main goals that Qantas and Southwest hope to achieve are greater operational efficiency while shortening the flight paths on final approaches and departures, cutting fuel burn, reducing carbon dioxide emissions, and shifting noise away from residential areas where possible.

Many other U.S. airlines are waiting in the wings, with some initial RNP capability already in place, and will probably follow the Southwest lead as it completes its program over the next five years. Southwest asked Naverus to design RNP procedures ideally suited to the performance capability of its 737 fleet so it can squeeze every bit of economic benefit out of its nationwide program.

RNP is already thriving in Alaska, Canada, New Zealand and Tibet. Still, the success of RNP at those locations has not persuaded all U.S. carriers of its utility. While the procedures may work well in mountainous Tibet, some U.S. airline officials wonder if RNP applies to their operations. In the meantime, WestJet is using about 80 RNP procedures at the 20 airports it serves in Canada. Flying to all types of airports matches what Qantas is already doing and Southwest plans to do.

Southwest has about a dozen employees and 85 contractors working on what it calls "The Automation Transformation." This includes not just the transition to RNP but a move away from the carrier's basic "round-dial" cockpit philosophy. Until now, Southwest pilots have not used autopilots or autothrottles even when such equipment was installed on the 737NGs that were delivered by Boeing. Instead, the company standardized on the classic 737 cockpits and even installed metal covers on the switches of equipment it didn't want its pilots to use.

Speaking at a recent performance-based navigation (PBN) conference here sponsored by Naverus, Capt. Jeff Martin, Southwest's senior director of flight operations, said his company has devoted considerable resources to its RNP project, which will cost $175 million. About 150 airline representatives, air navigation service providers and aviation industry groups attended the event, which drew RNP program leaders from Alaska Airlines, Horizon Air, WestJet, Air New Zealand, Qan­tas, Air China and LAN Airlines.

Two years into its RNP makeover, Southwest is embarking on a three-phase pilot training and education program that will span 3-5 years. The company's 5,500 pilots will first learn about autothrottles, automation and vertical navigation. The second phase will teach pilots how to perform basic GPS approaches. The final phase will focus on RNP.

During 2010-13, the company will retrofit 215 classic 737s with glass cockpits. It will also activate autothrottle systems and vertical navigation features on its entire fleet and upgrade software on all aircraft. In the meantime, Naverus will develop customized RNP procedures for all the airports Southwest serves, while Southwest also works closely with the FAA. "It's going to take a joint industry/government collaborative effort to make this [program] succeed," says Martin, adding that FAA leadership is providing "great support" for the effort.