Easterly Alternation is a programme intended to give communities local to Heathrow more predictable respite from noise. Heathrow is delivering Easterly Alternation to meet Government policy, following their ending of the ‘Cranford Agreement’ in 2009. This will allow us to alternate the use of our two runways during easterly operations in the same way that we currently do during westerly operations.
More detail on Easterly Alternation, the two projects – Ground Infrastructure and Airspace – which form it, and progress on delivery is on this webpage. If you have other questions, please contact us at communityrelations@heathrow.com (for ground infrastructure) and/or airspace@heathrow.com (for airspace).
This proposal will be implemented within our current two-runway operation and does not seek to increase Heathrow’s annual air traffic movements (ATM) cap of 480,000.
Note: this video was produced prior to planning application submission in October 2024
Heathrow awaits the decision on our application to Hillingdon Borough Council, which is required in order to build the necessary ground infrastructure.
Heathrow is currently undertaking Stage 3 work of the CAP1617 Planned and Permanent Redistribution of Air Traffic (PPR) process. Consultation is anticipated for 2026, after we pass the CAA Stage 3 Gateway.
The project team completed a period of community engagement in September 2024, visiting neighbouring communities that will experience a change from Easterly Alternation. We would like to thank those that visited our events and provided the team with useful insights.
The planning proposal was then completed and submitted to the London Borough of Hillingdon (Hillingdon) in October 2024. Hillingdon has since completed a public consultation on the proposal submitted, which ran from 14 November 2024 until 16 January 2025.
Details about the application and its progress can be found here on Hillingdon’s website - London Borough of Hillingdon - Planning
Included in the planning proposal is further information about planning, design, environmental assessments, as well as details about the noise mitigation offer. Our Summary Document below helps explain these details.
Heathrow is awaiting a decision from Hillingdon on the planning proposal.
An airspace change proposal (ACP) was submitted to the CAA via a Statement of Need. Following a formal Assessment Meeting in January 2025, the CAA has determined that Heathrow should commence a formal CAP1617 Planned and Permanent Redistribution of Air Traffic (PPR) Proposal. As stated within the Town and Country Planning Application to Hillingdon, the planned and permanent redistribution will be implemented within the current notified airspace, utilising the existing flight paths we have today.
Heathrow will provide updates as we progress through the CAP1617 PPR Process, which is also available on the CAA Airspace Change Portal (ref: PPR-2024-001).
We have developed proposals for the first phase of a project to enable full runway alternation during easterly operations. Easterly Alternation is being brought forward following the Government’s historic decision to end the Cranford Agreement.
This project consists of two elements:
This element of the project will require planning permission from Hillingdon under the Town and Country Planning Act 1990.
The second element will require Heathrow to comply with the CAA airspace regulatory procedures to utilise the current airspace structure for full runway alternation during easterly operations. The CAA has determined that Heathrow should follow the CAP 1617 Planned and Permanent Redistribution of Air Traffic (PPR) process.
The two elements of the project are required to enable Heathrow to alternate runways when on easterly operations in the same way we already do for westerly operations. It will also provide more equitable distribution of aircraft noise for our local communities.
Our proposals for Easterly Alternation will not change the number of aircraft flying in and out of Heathrow. They are also not a pre-cursor to any potential airport expansion. This project is to support the end of the Cranford Agreement and allow more equitable distribution of noise for local communities.
The Cranford Agreement was established in 1952 as a verbal agreement between the Government and Cranford, a village at the eastern end of the northern runway.
The agreement prevented aircraft from taking off over the village except in exceptional circumstances. For example, we took off over Cranford during the Covid-19 pandemic when we operated on one runway.
Following a consultation, the Government ended the Cranford agreement in 2009, to provide more predictable periods of noise respite to all communities surrounding Heathrow.
In 2013 we made an application to the London Borough of Hillingdon for the same project, this was granted planning permission from the Secretary of State in 2017. However, we didn’t go ahead with the works then, because of the proposals for the third runway. The previous planning application has now expired.
Although the Cranford Agreement has ended, we have not yet introduced Easterly Alternation on the northern runway because the airfield requires our proposed infrastructure changes to achieve this.
For safety and performance reasons aircraft typically take off and land into the wind. This is because the aircraft’s wing relies on the speed of the air moving over it (airspeed) to lift the aircraft off the ground.
Today, for 30% of the time we operate on easterly operations (taking off towards London) when aircraft generally land on the northern runway and depart from the southern runway.
Aircraft currently only depart to the east from the northern runway in exceptional circumstances, due to the legacy of the Cranford Agreement.
During the day, when planes are landing and taking off towards the west (westerly operations) we alternate the use of our two runways to provide local communities with respite.
The alternation pattern means that for part of the day we use one runway for landings and the other for take-offs, then at 3pm we switch over.
At the end of each week, we switch completely so that communities get respite from planes in the morning one week and in the evening the next.
This project will support us in alternating between our runways when on easterly operations.
Easterly alternation will bring predictable periods of respite from aircraft noise during easterly operations at Heathrow (easterlies). Aircraft noise will be shared more equally – as it is today when we are on westerly operations.
This means we can offer our neighbours a schedule that will detail periods of flights overhead and periods of noise respite.
The image shown below is an extract from the 2025 westerly alternation schedule. Once we are further along in the project we will aim to provide further timetables for easterly alternation.
An Environmental Impact Assessment was submitted with our planning application for the ground infrastructure changes. It shows that Easterly Alternation will bring more predictable periods of respite for our local communities with noise levels shared more equitably around the airport.
Some communities will experience more noise overhead, as the legacy of the Cranford Agreement means they are not currently overflown regularly when Heathrow is on easterly operations.
Communities who are currently overflown when on easterly operations may experience a decrease in number of flights overhead each day, as the redistribution of existing flight paths will be further spread out over more communities.
Our proposals require some airport ground infrastructure changes to be made.
These include adjustments to the taxiways leading to the northern runway and the construction of a new noise barrier near Longford, which could be between 5 and 7 metres high.
Part of the noise barrier will replace an existing acoustic barrier running alongside Wright Way and a fence which marks the boundary of the Terminal 5 POD car park. The images below show the location of the noise barrier and a visualisation of what the noise barrier might look like when constructed.
To support this project, we held seven engagement events in the local community during September 2024, prior to submission of our Town and Country Planning Application to Hillingdon Borough Council.
| Location | Date | Time |
|---|---|---|
| Isleworth Public Hall | Tuesday 10 September | 16:00 - 20:00 |
| Southall – Havelock Family Centre | Wednesday 11 September | 12:00 - 17:00 |
| Longford Thistle Hotel | Thursday 12 September | 15:00 - 20:00 |
| Cranford Community College | Saturday 14 September | 10:00 - 14:00 |
| Stanwell Moor Village Hall | Tuesday 17 September | 13:00 - 17:00 |
| Old Windsor Memorial Hall | Wednesday 18 September | 10:00 - 14:00 |
| Longford Thistle Hotel | Thursday 19 September | 16:00 - 20:00 |
If you were unable to attend one of our events and have questions for the project team, please contact the team by email at communityrelations@heathrow.com.
