I first joined the Civil Service in 1971 the third London airport project was already started. It has remained a project for almost 50 years a monument to how long our political elite can kick a can down the road and defer/avoid difficult decisions. Judging from the Huq MP comments this morning we are still no where near the end of the road. Judicial reviews etc will continue ad nauseam and trade and traffic will trickle away from Heathrow to Paris, Schipol, Frankfurt etc.
Its a salutary warning about what will happen to Brexit if MPs are put in charge. Brexit would never happen.Asking MPs to make decisions that might damage their vote is like asking Turkeys to vote for Xmas. It won't happen.
I can recall pretty well what I wrote in 72/73. Heathrow is pretty well in the best location for access from the rest of the UK. Gatwick is not. It is difficult to get to other than from the South coast. Stansted is also difficult to get to from many parts of the UK.
The only other solution involves a radical re-location of Government facilities out of London like Parliament and government depts like HMT.
I don't expect work to start on the third Heathrow runway in my lifetime. Most people think Maplin Sands was a Hi de Hi holiday camp not a failed third London airport plan.