RNAV1 Trials

This briefing is produced by London Luton Airport Operations Limited, in collaboration with local community groups, as part of the Airport’s ongoing commitment to reducing noise disturbance for its local communities.

A summary of this briefing is available to download as a .pdf from the foot of this page.

Why are we conducting flight trials?

Western departures from the Airport on routes via Clacton and Dover (see figure 1 below) are currently intended to follow a track which was designed over 20 years ago.

This “Noise Preferential Route” (NPR) seeks to avoid populated areas as far as possible. However, some aircraft are deviating outside the NPR corridor, overflying Hemel Hempstead and St Albans. Furthermore, the ground-based navigational technology currently in use is not as accurate as the latest satellite navigation aids. Such aids are now being introduced in Europe to positive effect, by keeping aircraft more tightly grouped along the “centre route”.

The aim of this trial is to see if switching to a more precise navigation system - called RNAV1 - will ensure those aircraft stay on the more tightly defined track, chosen to avoid populated areas as far as possible. We will carefully measure the environmental noise impact before, during and after the trial as well as gathering feedback from the local communities.

The overall intention is to agree a track which has the least noise impact for local communities, improve the tightness of track-keeping by the aircraft, and then consider deploying the new technology on other routes from the Airport.

Figure 1 (To see a larger version of this map, download the pdf at the foot of this page)

What will be achieved by the RNAV1 trial?

The aim of the RNAV1 trials is simple; to assess the community benefits of two alternative options for progression to a full Airspace Change Process (ACP).  The main change is to tighten track-keeping and subsequently reduce noise levels over the most densely populated areas. This will be quantified not just by accurate monitoring and measuring through specialist equipment, but also by physical changes such as:

• RNAV1 reduces the dispersion of aircraft within the designated Noise Preferential Route (NPR) meaning tighter track-keeping, with aircraft flying closer to the route centreline of the designated route or Standard Instrument Departure (SID).

• Highly populated areas should see a direct reduction both in terms of overflying aircraft and associated noise levels compared to the present day.

• Aircraft technology is constantly evolving with many airlines opting to upgrade their fleet every 5 years or so.  This in turn means that the routes, where necessary, should be developed to align with the progress that aircraft manufacturers and airlines are making.  

Timetable - two-phased trials

The trials will be conducted in two phases from 7th March 2013 to 24th May 2013. Dates may vary slightly depending on weather conditions - for example we need westerly winds to fly the new tracks.

The routes which will be part of this RNAV1 trial are the Clacton and Dover Runway 26 departures (figure 1).

These flight paths have been targeted for the design of an RNAV1 departure route because of the possible community benefits RNAV1 procedures, incorporating satellite navigation, would have compared to the ground based navigation currently undertaken at London Luton Airport.  

The Detling route, which is very lightly trafficked, is excluded for the trial but will be included with any permanent change process.

These benefits aim to reduce noise disturbance to local populated communities which run along the Clacton and Dover departure routes.  

These trials are not being conducted to assess flyability of an RNAV1 route as this has been tested through simulator trials. 

The two RNAV1 trials are planned to take place as follows:

• From 7th March until 18th April 2013 the aircraft will fly at around 210 knots following the orange line (see figure 1). 

• From 19th April until 24th May 2013 the aircraft will fly at around 220 knots following the slightly different purple line (see figure 1)