The airport has apologised to long-suffering residents who were told for months that no changes had been made to flightpaths and has insisted it was not told of the change by air traffic controllers.

The National Air Traffic Service has now admitted that the change made to one route did lead to a greater concentration of planes to the south-west of Heathrow.

Now proven right, residents and the councillors that stood behind them face news that those responsible for changing the route have no plans to revert it back.

Bracknell Forest councillor Chris Turrell, who sits on the Heathrow Airport Consultative Committee, said: “I think there are still things we need to get to the bottom of. I did find it quite astonishing that it has taken so long to identify this change.

“I think there’s some questions to be asked of NATS about whether the routes can be reverted back, just to see what they come up with.

“We have had this bizarre situation where Heathrow’s people have been denying point blankly that there have been any changes when residents have been experiencing it first hand.

“The real relief will come if they can go back to something that’s better for residents.” The change was made to the ‘Compton’ route in June 2014, and continued to affect flights following the end of Heathrow’s controversial flight path trials on November 12 last year.

The route is used by 16 per cent of aircraft turning west from Heathrow and the change narrowed the amount of airspace planes are flying through from 13 miles to seven miles wide.

The airport said poor communication from NATS meant it was not aware of the change and told residents ‘in good faith’ that flight paths had returned to normal routes.

Heathrow CEO John Holland-Kaye said: “Because of the assurances we received, we in turn told residents in good faith that no changes had occurred. That is unacceptable and I unequivocally apologise to local residents.

“At my request, the chief executive of NATS has agreed to urgently review his company’s processes to ensure that NATS shares this information with the airport to prevent this happening again in the future.” The National Air Traffic service has also apologised for the lack of communication. In a statement, it said: “It was a procedural change to the way that aircraft are directed within existing airspace which has been implemented to enhance safety and efficiency.

“We should have realised that it might affect some of the same people as the flight path trials, but we didn’t and we are sorry for that. We most certainly had no intention to mislead.”