all this talk of third runway a Heathrow has me thinking .I may have came up with a solution ....wait for it and remember you heard it here first ...are you ready .......An underground runway . Wel, what do you think ?
I can foresee problems with services like the underground as well as gas, electricity and water, weecalf, however your blue-sky thinking has led me to almost the opposite extreme.
A double-decker runway built on stilts over the existing, apart from anything else it has the advantage of planes starting off closer to cruising altitude so drinkypoos will be served quicker.
Never wanted, don't need them Mam, I responded to Douglas's post which I think is workable, Man Airport / Heathrow all have Runway tunnels, it would be possible but not impossible as other may think.
///They're coming to take him away Ha Ha
They're coming to take him away ho ho he he ha ha
To the funny farm where life is beautiful all the time and he'll be happy to see those nice men in their clean white coats
They're coming to take him away Ha Ha///