Respite through runway and airspace alternation
At Heathrow we use specific runway operating procedures to manage noise and provide regular breaks from planes flying overhead for our communities.
With expansion we will be able to provide respite to communities affected by aircraft noise in two ways:
- By alternating our runways, we will provide respite for those living closer to the airport; and
- By alternating our airspace, we will provide respite for those living further away.
Our recommendation is that you read about both runway and airspace alternation below because you may be affected by either type.

Questions – Respite through runway and airspace alternation
While looking through the information below please keep in mind that we are asking for your feedback on the following question in three parts:
- Would you prefer to have longer periods of respite less frequently (all day on some days but no relief on other days) or a shorter period of respite (e.g. for 4-5 hours) every day?
- Any reasons you have for your preference
- Any other comments or suggestions you have on runway and airspace alternation
What is runway alternation?
We know that noise from planes can be disruptive to communities around Heathrow. Today, when planes are landing and taking off to the west (westerly operations) we alternate the use of our two runways to provide local communities with respite.
Communities around Heathrow place great importance on the alternation system and we make every effort to stick to it. This alternation pattern means that for part of the day we use one runway for landings and the other for take-offs then, halfway through our day at 3pm, we switch over.
This gives some communities approximately 8 hours of respite a day.
At the end of each week we switch completely. What we did in the evening during the previous week, we now do in the morning and vice versa. This is so that communities get respite from planes in the morning one week and in the evening the next.
When planes take-off and land towards the east (easterly operations) we do not alternate the runways because the taxiways are not in place for us to do so effectively during daytime operations.
With an expanded Heathrow we intend to introduce runway alternation on both easterly and westerly modes of operation, giving respite to communities to the east and west of the airport.
With three runways we will be changing this so that one runway is used for arrivals, one runway is use for departures and the remaining runway is ‘mixed mode’ which means it will be used for both departures and arrivals. Each of these operating procedures are explained below.
Arrivals, Departures, and Mixed mode runway operations explained
How would runway alternation work for an expanded Heathrow?
Operating all three runways in mixed mode would deliver the most capacity for an expanded Heathrow but as you will see with the runway operating patterns, this would not provide respite to local communities so it has been ruled out.
We will always have to have one runway operating in mixed mode to ensure a balance of arrivals and departures at the airport. The middle runway at an expanded Heathrow will never be in mixed mode for safety reasons so it will always be an arrivals or departures runway.
This means that there are four runway operating patterns to achieve the benefits of alternation for all affected communities. The diagrams below show how the four patterns could work on both westerly and easterly operations.
Each pattern provides respite for two areas at once and the introduction of mixed mode means that some areas will also experience less intense periods of aircraft flying overheard.
We plan to cycle through these runway operating patterns so that every community gets a share of respite.
Runway alternation patterns during westerly operations
Please use the left and right arrows to navigate between the diagrams below. A description of each is available within the caption.
Runway alternation patterns under Easterly operations
Please use the left and right arrows to navigate between the diagrams below. A description of each is available within the caption.
How long and how often will respite be for?
We know that in order to provide daily respite for every community close to the airport we would need to use each of the four runway operating patterns shown.
That means that if each runway operating pattern was of equal length there would be a change every 4-5 hours.
Alternatively, we could provide longer periods of respite, but not every day. It is not possible for every community to have respite every day for more than 4-5 hours.
We want your feedback on two options for the delivery of respite to local communities using our runway alternation patterns:
- A pattern that delivers longer periods of respite, less often
We could use each operational pattern for a whole day, then move to a different operating pattern each subsequent day. This would mean that communities would get a whole day of respite every few days but have consecutive days of overflight with no respite.
- A pattern that delivers shorter periods of respite, more often
We could use each of the four runway operating patterns during the day which would mean that each which would mean that each community would have 4-5 hours respite every day.
What is airspace alternation?
With the modernisation of our airspace we are also developing our flight paths to provide ‘airspace alternation’ which will benefit communities further away from Heathrow.
The first diagram below shows how aircraft currently arrive and depart from Heathrow.
The second and third diagrams show illustrations of how aircraft could arrive and departure from Heathrow in the future using airspace alternation to provide respite to communities further away from Heathrow.
Please click on the left and right arrows to scroll through the diagrams.
How can flight path alternation also be used to offer noise respite?
Flight path alternation is another method of alternating the position of aircraft within airspace alternation to provide respite for local communities. Flight path alternation involves having multiple flight paths from each runway end so that we can alternate, or “switch on/off” the use of flight paths at different times. This would share aircraft noise across different communities to offer respite even when the same runway is in use.
The combination of airspace and flight path alternation will offer relief from planes over a much wider area than today.
What questions are you asking for feedback on in this consultation?
On this topic we are looking for your feedback on the following question, in three parts:
- Would you prefer to have longer periods of respite less frequently (all day on some days but no relief on other days) or a shorter period of respite (e.g. for 4-5 hours) every day?
- Any reasons you have for your preference
- Any other comments or suggestions you have on runway and airspace alternation