Here at yourHeathrow we’re dissecting the noise debate with a look at the issues, under the flight path, and what Heathrow is doing to reduce the impact of noise.
A noisy issue…
It’s important to acknowledge the impact aircraft noise has on the surrounding community and how noise effects people differently. While the health threats of noise are unclear, we know noise can cause distraction, sleep disturbance, speech interference and general annoyance for residents.
The direction that aircraft fly at Heathrow depends on the wind direction, as aircraft must take-off and land into the wind. Wind direction around London is mainly from the west. Most aircraft arrive over London from the east and take off towards the west; we call this westerly operations which occurs on average 70% of the year. During easterly operations, aircraft will arrive from the west over Windsor and this occurs on the remaining 30% of the year.
Aircraft coming into land at Heathrow use what is known as the Instrument Landing System or ILS. The ILS is a beam that is aligned with the runway centreline to guide aircraft in a straight line approach to the runway for landing. Any area beneath the ILS will be overflown by arriving aircraft. Additionally any areas to the sides of the ILS can be overflown by aircraft being directed to the ILS. Aircraft arriving at Heathrow airport join the ILS from both the north and south.
The number of flights using Heathrow has not changed significantly for over 10 years. During busy periods, arriving aircraft perform a fixed circling pattern known as stacks while waiting to land at Heathrow. All airports have a number of stacks of which Heathrow has four: Bovingdon; Lambourne; Ockham and Biggin. The stacks have been in the same location since the 1960s, which is set by Government policy. Unlike departing aircraft that have fixed directions, there are no set routes for aircraft moving from the holding stacks to the final approach (landing) and this is why residents hear aircraft on some days and not others.
Want to see where aircraft are flying in relation to where you live or work? Check out our online tracking tool.
Turning down the volume on noise
Despite double the number of aircraft since 1974, the noise level has actually reduced for residents living under Heathrow’s flight paths. With some of the toughest noise restrictions in the world, noise is at the forefront of Heathrow’s agenda with a number of approaches taken to make operations quieter.
Airlines are incentivised to use quieter aircraft through the imposition of fines for noisy aircraft and reduced charges for quieter aircraft. Later in the year we’ll be taking this one step further by ranking airlines noise performance.
In order to provide relief from noise for residents living under the path into Heathrow, we operate a runway alternation programme when we are on westerly operations. This means one runway is used by landing aircraft between certain timeframes and halfway through the day arrivals then switch to the other runway until the last departure. The pattern alternates on a weekly basis with flights landing on the southern runway in the morning and the northern runway in the afternoon and vice versa.
The Continuous Descent Approach enforced at Heathrow, whereby aircraft make a continuous steady angle approach rather than the traditional steeped approach, also helps reduce engine noise. Additionally, we’ve also launched the Fly Quiet Programme which records and ranks airlines against each other in terms of sustainability measures, including noise.
For more info on everything noise related please check out our Noise factsheet.