Heathrow has announced plans to change approaches to the airport to allow an extra 25,000 flights a year before a third runway is built.
Flight paths will be altered, allowing some residential areas a break from overhead flights but cutting respite over parts of west London.
The consultation will feed into a Government review of the UK's airways.
"Heathrow's aim is to design a sustainable, fair and more efficient future airport," a spokesperson said.
Executive director for Heathrow expansion Emma Gilthorpe said: "We are committed to delivering expansion responsibly and we encourage everyone to have their say and take part."
Communities living near Heathrow airport are currently given half a day's break from noise as the direction of take offs and landings is alternated during the afternoon.
Heathrow is also proposing to allow simultaneous take off and landings on its two runways.
This will lead to respite periods dropping to eight hours as part of measures to be implemented if a third runway is built, according to Heathrow Association for the Control of Aircraft Noise (Hacan).
But the proposals mean vast swathes of London and the Home Counties will receive a predictable break from aircraft noise for the first time, as the respite area is extended.
An extra 68 extra flights a day could be accommodated under the new system before a new runway opens and allow greater capacity during "particularly busy periods".
Laurie Anders, who would have the respite period for the flight path above his house in Chiswick cut, called the plans "very bad news".
Mr Anders said: "It's going to make life more difficult and upsetting."
The consultation will also look at airspace changes needed to accommodate "an expanded Heathrow" and how operating three runways will work in the future.
Hacan chairman John Stewart said: "It amounts to a near-revolution to Heathrow's flight paths."
Without a third runway, the proposals set out "probably the fairest system," Mr Stewart said. But "if it's built, it's far from a perfect deal," he added.
"Living under a flight path is like a shadow which you can't shake off. It affects people's health and people's quality of life."
MPs backed plans to build a third runway at London's Heathrow airport in June 2018.
The consultation will run until March 4.