TRIAL procedures for airline pilots flying in and out of Southampton airport have been made permanent.

Jets and large propeller planes now have to stay in line with the runway when landing from the south or taking off towards Winchester. The changes were approved by Southampton Airport Consultative Committee, which is made up of airport officials and community representatives.

The hope is that the new routeings will bring a reduction in noise heard on the ground.

Until the trial started last summer, affected aircraft had to stay in line with the runway only for two miles after take-off.

Now they have to remain on the imaginary "runway extension line" for 2 miles. Only then can they can turn off and head for their destination.

That means airliners taking off towards the north, but destined for France or Spain, are clear of the populated areas of Hiltingbury and Bishopstoke before commencing their turn to the south.

The modified routeings were devised by a "technical working group" of aviation experts and council representatives, including Eastleigh council's Tony Wright.

Explaining the northbound procedure to the committee, he said: "This aims to reduce incidents of aircraft turning over the more built-up areas and means the aircraft should generally be at a higher altitude, thus giving rise to less noise impact."

The new arrangement for planes approaching the airport from the south is that they must line up with the runway centre line at least four miles before touchdown.

Previously, airliners could cut the corner by joining the final approach line as little as two miles out. The effect of both changes is to concentrate noise in a more narrow corridor.

The technical working group recommended that last summer's trial be made permanent following analysis of residents' comments and complaints, and after a computer prediction of noise on the ground.

Mr Wright warned that the reduction in noise was likely to be small and that, because it was to "visual flight rules" only, it would not be binding on pilots in low cloud.

The rule change does not affect one of the noisiest aircraft types using the airport. Trislanders operated by the Channel Islands airline, Aurigny, will continue to overfly Hiltingbury on their way to Alderney.

Mr Wright said the slow speed of the triple-propeller plane meant it would delay other aircraft if it remained on the runway line longer.

"Although in the past it's been a cause of some complaints,because it can be a slightly annoying, noisy little aircraft, we've found that generally speaking in recent years it hasn't been the cause of complaints," Mr Wright said. "Maybe people have got used to it."

l Flybe is to be joined by a second airline flying from Southampton Airport to Guernsey. From Monday, the Channel Islands-based airline, Blue Islands, is introducing a twice-daily service.