UK air navigation services provider NATS has started a 14-week “consultation” process through January 21 to gather comments from airlines and other interested groups on proposed airspace changes surrounding Gatwick and London City airports. The consultation marks the first step in a wider program of proposed changes under the UK Civil Aviation Authority’s Future Airspace Strategy, an ATC modernization plan for the UK and Ireland.

NATS said the design concept of the London Airspace Consultation takes advantage of new navigational procedures and capabilities, including performance-based navigation (PBN) flight paths, that should significantly reduce conventional holds, or stacking of aircraft on approach to an airport. The concept also places new route structures over the sea where possible.

Later stages of the process will address airspace changes to other parts of the London airports network, with a targeted completion date of 2020. NATS said consultation on second-phase proposals for London Heathrow, Luton and Stansted airports will not take place before the winter of 2015.

The current first-stage consultation addresses airspace changes surrounding Gatwick Airport from the ground up, and surrounding London City Airport above 4,000 feet. It also proposes changes to some routes for traffic to and from London Biggin Hill and London Southend airports, which share airspace with London City Airport. NATS emphasizes that its information gathering centers on areas of airspace and not on routes, and that it will determine final route positions after the consultation with interested parties.

“Redesigning complex airspace such as that over London takes a long time; we have been working on concepts for the Gatwick Airport and London City Airport traffic flows for over two years,” the public-private organization said in an executive summary explaining the consultation. “This work has given us an understanding of how we can use PBN to change the method of operation for managing air traffic to and from these airports. We now know what kinds of routes are required and the general areas within which they need to be positioned. We have not, however, undertaken the detailed design work to finalize where the routes should go.”

NATS said the redesign would reduce aircraft noise, and that aircraft will climb higher and more quickly on departure and stay higher longer on arrival. But it cautions that “flight paths will change, and this may mean some areas will be overflown more than today, others less, and some [areas] will not notice any significant change.” It has included the possibility of designing “respite routes,” or additional routes that would provide “predictable respite from noise for people living below flight paths.”

The air navigation services provider seeks the views of airlines, airports, residents groups and councils and special interest groups such as recreational pilots within the affected areas. More information appears at www.londonairspaceconsultation.co.uk.