Heathrow has pledged to reduce night flights and curb noise pollution in a bid to win approval for a third runway.
The airport said it can meet the conditions set out in the Airports Commission’s recommendation for airport expansion.
Last July, the Davies Commission recommended expanding Heathrow but with strict conditions.
In one of its key pledges Heathrow will increase a ban on night flights to six and a half hours between 23:00 and 05:30 – up from their current 11:30pm to 4:30am.
However, the Commission’s report said it wanted a ban on night flights between 11:30pm and 6:00am.
John Stewart, chairman of the main anti-Heathrow expansion group HACAN, said: "Heathrow's decision to move on night flights could turn out to be significant.
"HACAN has long campaigned for a ban on flights before 6am, but things have remained the same for decades. Heathrow's proposals may prise open a door on night flights that has been firmly closed for 25 years."
Heathrow is also proposing for the Environment Agency to be given the role of an independent aviation air quality authority, to provide “transparent scrutiny” of the measures the airport will introduce to enable it to expand only in accordance with air quality rules.
Gatwick CEO Stewart Wingate said the latest proposal is a “desperate last throw” from a “failed” project.
"Heathrow can promise many things but they cannot wish away the reality of its location.
"An expanded Heathrow will impact hundreds of thousands of people currently not affected by aircraft noise – an expanded Gatwick would impact less than 3% of this number,” he added.