South African Airways’ (SAA’s) implementation at Cape Town International Airport of an innovative technique to ensure more efficient and more rapid landings, designated by the International Civil Aviation Organisation as the Required Navigational Performance-Authorisation Required (RNP-AR), is one of the world’s top such projects so far. With RNP-AR, an appropriately equipped aircraft, with an appropriately trained flight crew, can make more direct and curving automatic approaches to airports staffed with air traffic controllers who have also been trained in the technique. Previously, instrument approaches to airports required the aircraft to make dog-leg approaches with straight flight segments between the turns.

“With the RNP-AR, SAA can do three different runway approaches at Cape Town International Airport,” explains SAA senior first officer (flight operations and navigation specialist and project manager) Andrew Smit. “We can do it for Runway 01, Runway 19 and Runway 34 (which is the cross runway and never had an instrument approach procedure before). Also, we did it for three types and families of aircraft. And the technique is also used for departures from Cape Town, allowing shorter and more efficient departures. All this means that the programme was one of the biggest RNP-AR implementation projects in the world.”

“The new system does not replace the existing Instrument Landing System (ILS) in terms of landing in bad weather,” he elucidates. “The ILS is superior in bad weather. In good weather, the RNP-AR saves a lot of money. On a narrow-body aircraft flying from Johannesburg to Cape Town, we’re saving two minutes and 100 kg of fuel per approach. On wide-body aircraft, we also save two minutes but increase fuel saving to 200 kg per approach.” SAA operates 19 flights a day from Johannesburg to Cape Town, all but one of them using narrow-body aircraft. This gives potential maximum annual savings of 230 flying hours and more than 690 t of fuel.

“This technique greatly reduces the communications required between the air traffic controllers (ATCs) and the aircraft,” he points out. This means that the ATCs can concentrate more on managing the aircraft in their airspace and less on talking to them. This could allow ATCs to handle more aircraft in future.

Airbus ProSky was the company contracted to design and manage the project. It provided Operations Approval Packages and Flight Operational Safety Assessments. In parallel, SAA Technical upgraded the airline’s Airbus A319 and Boeing 737-800 aircraft to the RNP-AR 0.3 specification. SAA’s recently acquired Airbus A330-200 and A320 airliners arrived already fitted with the technology. “Airbus doesn’t offer the RNP-AR upgrade for the A340-300 but does for the A340-600,” he reports. “It is possible that SAA might later upgrade its A340-600s.”

Currently, Cape Town International is the only South African airport at which the new technique can be used. However, SAA has received approval to employ it at São Paulo’s Guarulhos Airport, in Brazil, and any SAA aircraft flying to or from Mumbai, in India, would be able to use it to land in the Seychelles, should the aircraft be required (for example, by bad weather) to make a diversion. The technique is being adopted by more and more airlines and airports around the world. “We would like the technique to become more common, both in South Africa and around the world,” says Smit.

The project has been funded by SAA and executed in close cooperation with the South African Civil Aviation Authority (CAA) and Air Traffic and Navigation Services. “Without the participation of these two parties, the project would not have been possible,” pointed out SAA Flight Operations head Captain Sandy Bayne last month when SAA announced the implementation of the technique.

Although the South African carrier has paid for the development of the approaches, a decision has been taken to make them publicly available to all operators who have the aircraft and crew capability. They will be published by the CAA in an Aeronautical Information Publication (better known as an AIP) and freely available. This decision could result in fuel savings, time savings and less carbon emissions.