The Government abolished the Cranford Agreement in 2009. But it will not come into effect until a final decision is taken on a third runway. This was the 50 year old understanding that planes did not take off from the northern runway over Cranford, at the Hounslow end of the runway. It meant that, when an east wind blows, all planes must land over Windsor on the northern runway so that they can take off from the southern runway. This has denied Windsor the half day’s break from the noise which West London enjoys.
Heathrow needed to do work on its taxiways to allow planes to take off from the northern runway. It got permission to this at a public inquiry but now wants to do further work on the taxiways so they fit in with any third runway. It is therefore planning to roll this further work into its more general detailed work on a third runway. If things go according to plan, it will not get planning permission for this until 2020/2021 after which the Cranford Agreement could become operational.