Sweden approves advanced navigation procedure to provide aircraft noise respite for Arlanda community
(photo: LFV)
Wed 3 June 2009 – From 2018, residents living in the centre of Upplands Väsby, south of Stockholm-Arlanda Airport, will suffer less noise from aircraft descending on their approach to the airport. Approved for the first time in Europe, an innovative curved approach procedure will be used by aircraft equipped with the necessary modern technology to avoid flying over the community. The Required Navigation Performance (RNP) procedure is a method of aircraft navigation that utilizes modern flight computers, Global Positioning System (GPS) technology and innovative new procedures to enable aircraft to precisely fly predetermined paths.
Over the last ten years, RNP has been refined for use in airport approach and departure procedures. RNP paths can be designed to reduce flight distances and lower thrust settings, resulting in millions of dollars in fuel savings for an airline as well as noise and emissions reductions that benefit airport neighbours andthe environment. Additionally, the accuracy and all-weather capability of RNP can enormously enhance flight safety.
LFV, which operates Sweden’s airports and air navigation services, has just received a preliminary approval for the procedure from the Swedish Transport Agency and will take effect from August, with no aircraft being permitted to fly over the centre of Upplands Väsby from 1 January 2018. The procedure, based on ICAO’s Procedure Design Manual (PDM) for Required Navigation Performance Authorization Required (RNP AR), contains three curves, two of them in the final approach to Arlanda.
Collaboration on the development of the procedure started back in 2004 when SAS flew a curved approach procedure in its 737 simulator and then five successful trial flights with curved approaches to Arlanda took place in 2005. However, there were no national or international regulations in place at the time to use the approach on a regular basis and the project stalled.
It was then taken up again early in 2008 when LFV’s Maria Ullvetter adjusted her originally designed procedure to comply with requirements published in a November 2007 final draft of the ICAO RNP AR PDM.
“There are a lot of parameters to take into account and when you change one parameter it has an effect on at least one other,” says Ullvetter. “For example, you have to consider bank angles, lateral and vertical accuracy, aircraft category, prohibited area (Upplands Väsby), obstacles such as the Arlanda control tower, temperature, glide slope angle, the aircraft’s most fuel effective speed and so on, including margins for error.”
For obstacle reasons, the procedure can be used at temperatures down to -15 degrees C. The procedure contains as few speed and height restrictions as possible to give the aircraft’s Flight Management System flexible possibilities to calculate an optimal environmentally friendly and fuel effective approach.
