Heathrow has revealed planes will be able to use both runways if they are running just 10 minutes late during two controversial trials at the airport.

Households living under the flight paths expressed their concern after BAA released further details of the proposals.

Campaign group Hacan Clearskies claimed the four-month trials - the first starting on November 1 - could spell the end of residents’ half day of rest from the sound of aircraft roaring overhead.

BAA, which has urged the airport’s neighbours to come forward with any concerns, said the measures would cut delays and reduce the number of night flights.

Tim Hardy, director of airside operations at Heathrow, said: “We understand residents’ concerns about noise in respite periods. That is why I encourage people to contact us to tell us their views during the trial.”

Planes landing at Heathrow currently switch runways halfway through the day to ensure households under the flight paths have a break from the noise.

The airport will still make the change at 3pm during the trials, but could temporarily use both if aircraft are running more than 10 minutes late.

John Stewart, chairman of Hacan Clearskies, said: “This is much, much worse than we had expected. This ‘10 minute rule’ could effectively destroy the respite period.”

Heathrow will carry out another three-month trial next summer during the Olympics.

BAA said small incidents at the airport could currently lead to delays because it was operating at close to capacity.

This causes frustration for passengers and planes burn more fuel as they wait to land, the group said.

Air traffic control would judge when the airport should use both runways simultaneously.

Such circumstances would include during a strong headwind on approach, when 30 per cent of flights are running outside the 15 per cent punctuality target and following a period of disruption caused by incidents such as snowfall. Mr Hardy said: “This trial has the potential to bring benefits to local residents, passengers and the environment. It will not result in any additional flights and could mean fewer unscheduled night flights and a more predictable and punctual service.”

The Government will launch a consultation before deciding whether to permanently grant the airport greater flexibility.

To contact the Heathrow community relations team with feedback on the trial, call 020 8745 5791 or email heathrowcommunityrelations@baa.com. For more information, visit heathrowairport.com.

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