I have to declare my interests: I live quite close to the flight path, and depending on the wind direction, it can be quite noisy over my head when the planes approach Heathrow. So if the government allows BAA to build a third runway in Heathrow or to use mixed mode, I will not be too happy about it.
If ‘Boris Island’, a plan to build a brand new airport in the Thames Estuary advocated by the Mayor of London, is not a viable option, then Britain must manage with what it has. I never understood why the transit passengers are so economically important – they literally pass through the airport – and they don’t bring much business to the UK, except to the airlines (British Airways) and the airport operators. It may mean that some routes become unprofitable because there are not enough passengers, but can’t the airline then use a smaller plane? Transfer in Heathrow is a nightmare in most terminals and there is a pretty high risk that your luggage go missing. Heathrow serves fewer destinations than the likes of Frankfurt or Paris, but does it really matter that much?
There are practical ways to reduce pressure on Heathrow. Why can’t Air France run high-speed direct trains from St. Pancras to Charles de Gaulle, as it already does from Brussels? Or why not merge BA with Iberia, fly a frequent service to Barajas using big planes, so that Madrid can take the extra passengers and travellers going to more exotic destinations. BA can expand on its OpenSkies outfit and use Barajas as its hub. Heathrow will keep the most desirable and lucrative destinations: people will pay for the convenience.
Finally there is a fantastic solution to this problem I’ve read somewhere. It involves building a huge airport in northern France near the Channel Tunnel: link the new airport with high-speed tracks already in existence and passengers can reach London, Paris, and Brussels within an hour. Amsterdam may take a bit longer but still feasible. A bit mad, but I think it’s a great idea.