This is what I love about this thread. I posted this morning, then commitments took me elsewhere. Returning, I find over 20 further contributions. And dj6 not ruling out 10m pax takes me to a place so far in the future I do not normally go there. After a thoughtful Cotes du Rhone (or two), I have to agree it could happen - despite previously stating it wasn't possible - because, like dj6 and our dear friend southside, I cannot see R3 at LHR in my lifetime, and if London remains one of the great global capitals, then aviation demand will surely have to be absorbed by other London airports.