Hundreds of aircraft could fly at low-altitude over Richmond Park, if plans described in new consultation documents are approved.

Maps of the potential new flight path, which were released as part of the consultation process for a third runway, reveal the extent of proposed air traffic over the Royal Park.

The maps show that some planes could fly as low as 300 metres (1,000 ft) and the current flight paths do not go over the park.

Richmond and Twickenham Times:

“Design envelopes” - broad geographic areas designed using feedback from previous airspace consultation.

The Heathrow Airspace and Future Operations consultation, which follows MPs’ approval of the third runway last year, indicates that 47 arrivals an hour and between 17 and 47 departures would fly directly over the park at below 900 metres.

Heathrow’s flights are currently capped at 480,000 a year, but it wants to increase this by 25,000 in 2021 and further when the third runway is built.

Environmental campaigners say the noise and pollution will be disastrous for the wildlife and the tranquility of the park, which is visited by more than 5.5 million people a year.

The park, which stretches over 1,000 hectares (2,500 acres), is a site of special scientific interest, a national nature reserve and a European conservation area.

Sir David Attenborough said in a recent documentary that the largest royal park in the capital was home to thousands of wildlife species supported by the sensitive and legally protected grasslands.

The changes to flight paths will start in 2021, because Heathrow plans to increase flights by 25,000 a year before the proposed third runway is built, and will be adopted in full on completion of the third runway in 2026.

The airport has placed noise monitors across the park in preparation for the proposed flights.

Ron Compton, the chairman of Friends of Richmond Park, said: “It is disastrous. It is shocking to see the potential impact the proposed flight paths could have on Richmond Park and its wonderful wildlife and environment so treasured by millions.

“The park is the darkest and the quietest place in London and this will be shattered by these new flight paths. Increasingly, medical experts and even government bodies recognise the important value of green, quiet open spaces to the nation’s physical and mental health. We call on all the millions of visitors who treasure the park to protest against these proposals.”

The expansion of Heathrow airport from two to three runways will be challenged next month in a judicial review that will involve five separate legal challenges, including Richmond and Wandsworth Council.

A Royal Parks spokesperson said: “We have responded to the latest consultation from Heathrow on the proposed changes to flight paths and the operation of Heathrow runways.

"To summarise, our position is that we understand the principle of prioritising flightpaths over commercial and industrial areas, but disagree that routing flights over parks should be similarly prioritised due to the impact it could have on the wildlife, ecology and tranquillity of parks.

“Large parts of the Royal Parks estate could potentially be affected by changes to flight paths, but we are particularly concerned with the potential impact on Richmond and Bushy Parks because of their proximity to Heathrow Airport.

 “To conclude, there has been no direct consultation with Heathrow about these proposals, and we would welcome more detail once the full impact of the proposals can be demonstrated to us, in terms of measurable changes to noise and air quality, compared with current operations."

A Heathrow spokesperson said: “Our consultation is an opportunity for Richmond and Twickenham residents to share their views on future airspace proposals around Heathrow, some of which need to take place regardless of expansion.

"At this point, we are consulting on local factors to consider inside “design envelopes” - broad geographic areas designed using feedback from our previous airspace consultation.

"When it comes to Richmond and Twickenham, feedback on local factors such as the impacts on Richmond Park will be taken into consideration. We will be presenting final flight path options and full analysis of each route in further consultations, and will keep engaging with local residents until then.”

The consultation closed yesterday (March 4)