Runway alternation currently only happens on westerly operations (when aircraft come into land over London and take off towards Windsor). This is because of the legacy of the ‘Cranford Agreement’ which was established in the 1950s. Cranford is a village at the eastern end of the northern runway (as illustrated below). The agreement prevented aircraft from taking off over the village except in exceptional circumstances and applied when Heathrow was on easterly operations.
For arrivals, this means that on easterly operations, the vast majority of arriving aircraft will land on the northern runway, with the vast majority of departures only taking off from the southern runway.
The agreement favoured residents of Cranford at the expense of other communities such as Windsor and southern parts of Hounslow.
In 2008, the Government consulted with local residents about the Cranford Agreement. After reviewing the results of the consultation, they announced that the agreement should end in 2009.
In 2010, the then Government confirmed that the Cranford Agreement should be removed, and that Heathrow should take the necessary steps to implement easterly alternation as soon as possible to ensure a fairer distribution of noise when operating on easterlies.
Heathrow submitted a planning application to the London Borough of Hillingdon in 2013 to construct an additional taxiway at the western end of the northern runway to enable full runway alternation on easterly operations. This would bring into effect the ending of the Cranford Agreement.
Planning permission for the application we made in 2013 was granted on appeal by the Secretary of State on 2 February 2017. However, on the same day the Government published the draft Airports National Policy Statement which supported the expansion of Heathrow. The NPS has now been formally designated. The airfield design for an expanded Heathrow means we need to reposition the taxiway works. This requires a new planning application and we intend to pursue this work through the planning process for expansion.
There are two different processes we need to go through in order to implement easterly alteration:
We plan to submit our Development Consent Order (DCO) in 2020 with consent expected in 2021. We will then move ahead as quickly as possible following DCO consent to build the necessary taxiway infrastructure – we expect this to take around two years, and so easterly runway alternation could be introduced by late 2023/early 2024.
Alongside this, we will also be required to go through the CAA’s Airspace Change Process to seek approval to change the distribution of flights (i.e. regular departures from the northern runway and regular arrivals on the southern runway) that will result from introducing runway alternation on easterly alternation.
Introduction of runway alternation on easterly operations
Airport Expansion Consultation June (2019)
DCO submission (2020)
DCO decision (2021)
Easterly runway alternation (late 2023/early 2024)