Australia unveils nationwide RNP project

 - July 28, 2009, 6:59 AM

When the Australians decide to go for something, they really go for it. Example: the FAA awarded its nationwide automatic dependent surveillance broadcast (ADS-B) contract in 2007. The Aussies did it more than three years earlier.

Another example: the local area augmentation system (LAAS) is still in development in the U.S., and no operators are using it yet, other than on occasional non-revenue evaluation flights. Qantas, meanwhile, has its entire Boeing 737NG and Airbus A380 fleets equipped to fly the ground-based augmentation system (Australia’s LAAS) on all VFR approaches, including autolands, using an identical development system at Sydney, and has been doing so regularly since 2007.

The same is true for the nation’s required navigation performance (RNP) project, announced last month. The project’s team of Airservices Australia and RNP specialist Naverus of Kent, Wash., will introduce some innovative concepts aimed at a wide user spectrum. Airservices intends to have RNP approaches to each runway at 28 airports, ranging from large international hubs to some non-towered locations.
Qantas 737NGs had been routinely flying company RNP-0.1 procedures since 2006.
With just a few exceptions, FAA’s RNP activity has been aimed primarily at medium-size airliners, specifically the Boeing 737NG, under an almost generic “one size fits all” procedure design approach. The Australians have moved a major step ahead in adopting what they call a multivariant design, where procedures are developed to assure RNP’s benefits across a range of aircraft types.

This multivariant design recognizes four distinct aircraft groups that have sufficiently different operating characteristics–such as turn rate, speed, vertical path and distance to rollout onto final approach–to justify separate procedures. The groups are regionals (typically turboprops); narrowbodies (typically A320, 737/BBJ); two-engine heavy (typically 767, A330) and four-engine heavy (747, A340, A380).

Peter Curran, Airservices Australia manager for network services, told AIN, “At most airports, separate procedures will be tailored to fit the very different performance characteristics of large aircraft such as the A380, and those of smaller regional turboprops and narrowbodies. We want to maximize the benefits of RNP for users.”

Australia’s RNP procedures will begin at the top of descent, to include a continuous descent to final. Officially approved are arrival procedures called Visual RNav Stars (formalized VFR shortcut approaches), which will become Visual RNP Stars.

The nation’s enviable attitude toward aviation is also the reason that, with the exception of Category III service at Sydney, all of Australia’s ILS installations are Category I. Accordingly, Airservices calls for basic RNP-0.3 as its qualifying capability, to minimize compliance costs in smaller aircraft, although Qantas and other large carriers are expected to maintain their RNP-0.1 equipage.

Yet with all this upbeat activity, it’s disheartening to learn that one innovative Australian aviation scheme was torpedoed by a familiar, worldwide adversary. To bring everyone into ADS-B, Airservices planned to provide free avionics units to general aviation pilots. Until, that is, the tax folks got wind of it. Those free units suddenly became expensive, and had few takers.