Reply from HAL
An increase in ATMs before a new runway is built will require airspace changes that improve runway efficiency for both arriving and departing aircraft which will enable a small increase in runway capacity. Very simply, this will be achieved by reducing the gaps between aircraft. New technologies for arrivals are already being developed and progressed that could deliver this efficiency which would enable us to introduce the 5.30am start time at the same time as the additional ATMs. We know how important maintaining periods of respite is for people living near the airport. There are no plans to change the rules around TEAM. More efficient use of the runways means we could enable an increase in ATMs while maintaining runway alternation.
As we said in the newsletter, any increase above our planning cap of 480,000 flights per year would be subject to public consultation and planning permission.