No it's a crazy idea. Frequent fliers, ie me, want the airport near them. You would have to forcibly shut Prestwick and compensate Infratil as the Glasgow traffic would fragment to Prestwick and this new super airport. It would also be less than ideal for Edinburgh businessmen as it's.....NOT NEAR EDINBURGH. So aside from being less than ideal for both markets it's a brilliant solution (!)
Gate 22, in the South East, we have NOWHERE away from built up areas that ANYONE is gonna let you concrete over. There's precious little unspoilt land as is. Be realistic. Be grounded. Be sensible. Be prudent. We don't have the same society as Hong Kong, the same builders or costs.
IT'S NOT EVER GOING TO HAPPEN IN LONDON, GLASGOW OR EDINBURGH. Deal with it. The rest is just hot air and blah blah.
On a more Heathrow note, anyone know what's being built between the piers at Terminal 1? Is it part of the Heathrow East project?