I have to agree totally with Sir George - I have never met anyone who wanted to travel through LHR, it is in the wrong place for the majority of the country and is exremely difficult to get to reliably due to the massive congestion on the roads in that part of the southeast.
On just the enviromental grounds any extra runway must be stopped - have you seen how much of central London would be under tha new flightpath.
As for the safety argument - if the capacity is such that movements become dangerous, then reduce the capacity (ie less slots). What will you do when the extra capacity generated by a 3rd runway is used up - build a 4th?
