Required Navigation Performance (RNP) Is Spreading

A system devised by Alaska Airlines and Boeing to help improve accessibility to notoriously difficult airports in the 50th state could soon help ensure better on-time performance on Lower 48 milk runs (relatively speaking).

After experimenting with Required Navigation Performance (RNP) systems at some of the U.S.'s tougher airports (Palm Springs and San Francisco among them) the FAA has decided the system can be implemented by any airline that has the right equipment and training.

"It's a game changer," FAA Administrator Marion Blakey told The Wall Street Journal. RNP harnesses the on-board computing power of modern flight management systems and avionics with GPS technology to allow aircraft to be programmed to fly a specific route into and out of an airport.

The route includes specific climbs and descents and deviations around obstacles, all controlled by the electronics. It eliminates the need for the traditional straight-line ILS approach that doesn't work well at some airports.

Airlines Should See Improved On-Time Performance

As AVweb reported more than a year ago, RNP has vastly improved accessibility to Palm Springs on the comparatively rare occasions when the weather is down there.

Because terrain prevents implementation of a standard ILS, diversions were usually the only option in bad weather. RNP allows Alaska Airlines to land at Palm Springs with minima of 250 feet and three-quarters of a mile.

But terrain isn't the only obstacle that hinders operations and RNP will find a use at airports surrounded by miles of flat expanses. For instance, Chicago Midway is limited by its short runways and proximity to O'Hare.

Currently, there are plans for RNP approaches to airports ranging from New York's JFK to Long Beach, Calif. According to the Journal, pilots and controllers like the system because they know exactly where the plane is going and when it will get there. Delta, JetBlue and Continental are all training for the system now and should have their FAA approval soon.