Sir George
I expect you are factually correct however as things currently stand:
Movement capacity at Heathrow balances exactly with the approved slots. If anything happens to reduce that capacity, even for a short period of the day, the Heathrow ATC staff come under a great deal of pressure for the rest of it.
Just the other evening we were forced by Tower staff numbers to go to 4 mile inbound spacing for a couple of hours. We had been landing low 40s per hour with virtually no holding. As soon as we opened up the gaps delays started to build and were sustained at over 20 minutes for some time.
In my time at Heathrow I have seen long term runway closure (hours) caused by aircraft incidents on a number of occasions, VIR, KLM, DLH. I have witnessed Heathrow sustain 62 per hour off the remaining runway for 4 hours, in awful weather. That sort of pressure leads to danger and it is not right that the ATC system is being asked to make up for Governments' unwillingness to give us the SPARE capacity we need. Spare is somehow seen as waste rather than a safety bolthole.
The first hour of the day often sees landing rates sustained in excess of 50 per hour as we land both runways... but through a single final director. That is nearly 20% more than he would usually handle with no additional r/t or thinking capacity.
On safety grounds alone Heathrow needed additional runway capacity 5 years ago. Irrespective of what decision HMG comes to over future growth, Heathrow must have additional capacity now. Corners are already being cut.
Point 4
