PROBLEMS with planes straying out of an official flight path from Luton Airport and flying over St Albans homes has prompted the airfield to start trialling a more precise satellite navigation system.

The move has been cautiously welcomed by campaigners fighting a scheme to substantially expand the airport and increase flights, both during the day and night.

The trial is being conducted in two phases, from March 7 until April 18 and from April 19 until May 24, and affects western departures travelling routes via Clacton and Dover – a track designed over 20 years ago.

A spokesman for the airport admitted that ground-based navigational technology currently in use was not as accurate as the latest satellite navigation aids.

Some aircraft are deviating from the noise preferential route (NPR) which is supposed to avoid populated areas like St Albans.

The satellite navigation aids being used in Europe are, according to the spokesman, better at keeping aircraft closer to the centreline.

It is the second time the airport has initiated a trial to resolve ongoing difficulties with planes not keeping to the centre of the air corridor.

There was a barrage of noise complaints from residents when Luton conducted a track-keeping trial between May and November 2011, which had some planes flying low or very close to Flamstead and Redbourn.

The airport received more than 7,000 emails and voicemails from about 350 households in those villages as a result.

A resident from Jersey Farm, who did not wish to be named, said that having studied Luton’s map of the proposed tweaked routes, it appeared the centrelines were much lower and going nearer to Hemel Hempstead.

She added: “I wonder whether they will continue going straight across and therefore more into St Albans.”

The woman said that Redbourn and Flamstead might benefit from the trial.

Sabra Swinson, spokeswoman for St Albans campaign group Save Our Skies said: “We are pleased that the airport has listened to our complaints over flights deviating from the NPR over St Albans and are undertaking these trials.

“We hope that as many St Albans residents as possible will send feedback to the airport between now and May 24, 2013, when the two-phase trial ends.

“This is our big opportunity to influence the path of flights over St Albans in the future and we should take advantage of it.”

Spokesman for Hertfordshire Against Luton Expansion (HALE), Andrew Lambourne of Flamstead, said: “We are going to give the trial a fair chance but in terms of noise, there is only a small percentage of planes taking part in the trial – only about 40 per cent of westerly departures.”

He and other sources said it was not clear from airport information how St Albans would be affected by the trial.

Luton is seeking feedback on plane noise during the trial, which can be emailed to rnav@ltn.aero or phone 01582 395699.

n Luton borough council has received around 380 submissions on the airport’s scheme to double passenger numbers to 18 million a year. A spokeswoman said she did not know when the planning application would be determined by the council.