Prop
It is likely that Heathrow will use all the space granted, then build a shorter runway not crossing the M25 after the costs overrun, and use it for short haul flights only. Then build on in the future when viable.
They cannot be trusted as per the Cranford runway alteration, planning permission granted then ignore it. I also believe the night noise quota will be for just one runway not the whole system. capacity is not relevant at 4.45am only later in the day, and not at 9pm plus.