Air New Zealand (ANZ) is the first airline to seek certification for its Airbus A320s to carry out approach procedures using required navigation performance (RNP) standards.
The airline is working with Airbus and Naverus, the Seattle-based experts in performance navigation, to gain a special Civil Aviation Authority (CAA) approval to operate its A320 fleet using RNP-based instrument approaches rather than visual approaches below existing VOR/DME minima (3000 ft AGL) at Queenstown airport. The RNP approaches optimize the performance of ANZ's Airbus fleet by taking full advantage of the aircraft's high-accuracy navigation. At this airport, surrounded by high mountain ranges, this enables ANZ to operate to significantly lower weather minima and to continue operations when bad weather previously closed the airport to all traffic.
With the new RNP 0.15 certification in approach, which was successfully gained by Airbus earlier this year, ANZ A320 aircraft will be able to land at Queenstown even in poor visibility and use curved approach flight paths. At present, aircraft inbound for Queenstown cannot descend below 3,000ft (900 meters) unless visual meteorological conditions prevail. Using the RNP 0.15 aircraft capability and the RNP RNAV procedures designed by Naverus, ANZ A320s will be able to land with minimum decision heights down to 270ft AGL.
All Airbus aircraft equipped with dual Flight Management Systems (FMS) and Global Positioning System (GPS) capabilities are already certified down to RNP 0.3 in approach. Most Airbus fleets can therefore already fly Instrument Approach Procedures published under ICAO PANS OPS (or TERPS) criteria. Such RNP RNAV procedures using a straight final segment already take benefit of the aircraft's RNP 0.3 capability. At airports such as Queenstown where access is restricted due to terrain, or at other airports where access is limited by environmental constraints such as noise, traffic or security issues, lower RNP values and/or curved final segments can provide significant operational benefits and improve flight safety. By optimizing trajectory, the RNP technology can also allow reduced approach time and fuel consumption.
The strong collaboration between ANZ, Airbus and Naverus led to a successful A320 demonstration flight to Queenstown in June this year. New RNP procedures featuring arrivals on both runways, missed approaches, and departures with all engines and with one engine failure were flown with autopilot engaged, using the new Lateral Deviation display. This new display allows the crew to monitor the flight path steering error directly on the Primary Flight Display.
ANZ's Airbus A320 fleet was delivered with all the hardware necessary to enable certification for these approaches, so that only a software update will be needed to get the Lateral Deviation display activated. Following approval from the CAA, expected at the end of this year, ANZ will begin to operate these new procedures using RNP 0.3 minima and collate information and experience before transitioning to the new certified RNP 0.15 values.