Just a few points to keep in mind.
1 – An estuary airport is a non-starter. It is too expensive and in the wrong place. Also the findings of the commissions of enquiry 40 years ago still stand up. Bird migration patterns and bad weather plus other known obstacles have not changed in that time.
2 – a new greenfield site for an airport is a non-starter. It is too much to ask to concrete over the green belt when so much is already concreted over with airports.
3 – that means there are four possibilities for expansion: Heathrow; Gatwick, Stansted and Luton. Anywhere else is off the map. Birmingham cannot expand and if you decide for East Midlands why not Luton?
4 – More than one hub is possible. Look at Paris (CGD and Orly) and New York (JFK, Newark and La Guardia).
5 – London´s airports are international and local. It is much more convenient to travel from Gatwick if you live in Hastings, while to get to Cambridge from abroad Stansted is the most convenient. Also look how Southend is developing. So closure is no option.
6 – From where do passengers want to fly?From where do airlines want to fly? I call this concept “supply and demand”. Persuasion is the only way to transfer travel patterns from one area to another. I remember that in the 1970s the government wanted to make better use of the underused Gatwick (spreading the load) by making all the foreign airlines move there who flatly refused screaming discrimination – this was a time when all BA´s routes were joint ventures with its foreign competitors – the same as the JVs over the North Atlantic today.
7 – closing Heathrow is no option after investing so much in its infrastructure over recent years. Extending the present two runways westwards towards the M25 could reduce some inconvenience over West London. A third runway is essential if only for safety/operational reasons – considering that LHR closed for some hours over the aircraft whose cowlings blew open. That was an incident which showed how fragile the operation is at LHR.
8 – Gatwick is a successful airport which needs a second runway for the same reasons as mentioned about LHR, and that is not considering increasing passenger movements.
9 – Stansted and Luton need to be looked at together, but as the potential for 4 (or more runways). STN has lots of room in the area but needs much better land connections North and West as well as to London. However, STN has lots of Nimbys in the area. Luton has much better connections both North and South into London. Its nimbys are fewer since the expanded airport would provide very welcome employment for the area. The terrain is more more challenging for development but certainly not so much as the quicksands of the Thames estuary, and certainly within the capabilities of the engineers and constructors. One of the two airports, depending on which is developed, would have to close or at least have its activity maintained at a low level so as not to interfere with the operations at the other as the main hub.
10 – public transport must be a priority in the development of any airport together with its connectivity with other airports and other points e.g. Central London, Reading etc. Strong dissuasory measures must be taken against the use of the car which is noisy, heavily polluting, the causeiof traffic jams and in most cases (in this context) completely unnecessary.
11 – Protection of the environment and the individual will come about by improved airframe and engine mechanics (the A350 on last Friday´s maiden flight proved to be surprisingly less noisy than expected), eliminating stacking by more runway capacity, by restricting certain aircraft types over built up areas and by restricting the total movements available so we do not reach saturation point as at present at LHR.
-My conclusions are that LHR should get its third runway and sixth terminal under strict conditions.
-Gatwick should get its second runway and make that the limit.
-A fast rail line should run from Reading through LHR and Gatwick to Ashford and the Channel tunnel. This could provide the possibilities of HS connections from the West, South Wales and Birmingham to the airports where passengers to Paris, Brussels, Amsterdam and Frankfurt (and places between)can travel thus dampening down demand for flights to/from those cities. This line would avoid London so not clog up the city as other proposals suggest.
-Luton should be promoted as an alternative hub expanding to four runways and improving its land links, especially to the WCML and the ECML.
Solutions are always possible but by looking at the whole picture and exercising some lateral thinking.