South African Airways (SAA) is implementing a new navigation approach that promises major benefits and savings for the airline and the industry. The new method will be used to guide the aircraft as they approach the airports for landing.
The innovation is in keeping with the airline’s long-term turnaround strategy which, among other areas, places emphasis on improving the efficiencies of the airline’s operations across the board. The announcement means that the airline will notice improved efficiencies and benefits in time and fuel savings as well as enhanced safety by reducing reliance on ground navigation equipment.
Fuel is one of the significant cost drivers in the business and this method is expected to have potential fuel savings estimated at R6,3-million, having a positive impact on SAA’s operating costs.
The technique, known as RNP-AR (Required Navigational Performance-Authorisation Required), employs curved segments to achieve not only a high level of safety, but also a more efficient flight path. This reduces the distance covered by the aircraft, saving fuel, time and reducing carbon emissions.
Unlike traditional instrument approaches, RNP-AR is not bound by restrictive “straight line” design criteria, explains SAA senior first officer Andrew Smit. “Using upgraded navigation systems, RNP-AR-equipped aircraft are able to fly a more efficient path as they approach an airport and prepare for landing,” he says. RNP-AR is independent of ground based radio stations unlike traditional means.
SAA initiated a pilot programme for RNP-AR technology at Cape Town International Airport in 2009 and, in an Africa-wide first, put it into operation by early 2013.
“Research conducted by French company, Airbus Prosky, showed potential savings of over 690 tons of fuel and a reduction of some 230 hours of flight time per year, based on an average saving of 100kg of fuel per approach and a reduction of two minutes’ flying time for each approach,” says Smit.
In technical terms, RNP-AR allows the aircraft to fly in curved Standard Instrument Departure (SID), Standard Instrument Arrival (STAR) and Instrument Approach Procedures (IAP) to a lateral accuracy level of between 0,1nm and 0,3nm. SID is a navigation procedure which guides aircraft after take-off, while STAR is a navigation procedure which guides the aircraft towards the airport before the aircraft begins the approach.
Airbus Prosky handled the project design and management, with the scope broadened to include the design of RNP-AR SID, STAR and IAP for routes into Cape Town from Johannesburg, Durban and London; and the delivery of Operational Approval Packages and Flight Operational Safety Assessments, which is the quality assurance process that ensures safety is not comprised.
Simultaneously, SAA Technical upgraded its Airbus A319 and six Boeing 737-800 aircraft to RNP-AR 0.3 specification. The recently-supplied Airbus A330-200 and A320 fleet arrived factory-equipped with this technology. The project was collaboratively executed among parties which included Air Traffic and Navigation Services (ATNS) and the South African Civil Aviation Authority (SA-CAA).
“Without the participation of these two parties, this project would have not been possible,” says captain Sandy Bayne, SAA head of flight operations.
After the completion of the design work, a period of VMC (Visual Meteorological Conditions) flight trials was done to prove the safety of the technology and to allow pilots and Air Traffic Controllers time to adjust to the new procedures.
“Full approval was granted to SAA for RNP-AR operations by the SA-CAA in March 2013, making it the first operator in Africa to achieve this milestone,” says Bayne, adding that SAA has since achieved approval for the technology in the Seychelles and Brazil. The US Federal Aviation Administration (FAA) approval is imminent.
With the success of the technology proven in practice, SAA is working with other operators to provide access to RNP-AR procedures for wider benefit to the aviation industry. The airline has approved the publication of its procedures in the State Aeronautical Information Publication (AIP), granting access to all capable and approved operators.
“This means Cape Town International has the potential to be one of the greenest airports in the world, as very few major facilities can boast a complete suite of RNP-AR SID, STAR and Approach procedures, which can feed aircraft with optimal approaches for every landing. These new procedures use less fuel, CO2 and allow the aircraft to be quieter than when compared to traditional flight procedures,” Bayne says.
