Fairdealfrank.
Yes agree with you on LHR.
They have spent big money on it ,and I don't think its likely to close.Even the current Govt are proposing to widen the M4 from Reading to Heathrow ,certainly wouldn't do that if they planned to close it, surely ?
LGW.. is probably out as a mega hub as business passengers have repeatedly shown they don't want to travel in large numbers even to LGW, its a top leisure route airport. If they did all the US Airlines would not have pulled out and moved to LHR.
STN, American Airlines have tried it twice and failed twice..not enough business passengers, as have SAS on one occasion and others. About 20 years ago the Govt in power tried to force full fare airlines into LGW from LHR.
They refused and remember the boss of Air Canada having a rant at the thought of it.
STN will most likely stay a low cost airport.
Isle of Grain or Boris Island. No chance Experts have already reported to the airport commission the greatly increased danger of bird strikes, and destruction of wetland habitats threatening tens of thousands of birds, at a time when such concerns are high on the agenda.
Then add on huge cost of starting from scratch, running new motorways and extending main rail lines and moving all the LHR workers to new housing estates.Then its also the extra distance into London city.
It will be a brave Govt who has to make a decision and in the short term you can see this topic running for some time.
However IMO its most likely that LHR will be expanded keeping everyone but the local residents happy .
Nigel