What also should be added to the mix is that the technology exists to completely rewrite arrival and final approach paths. These should incorporate RNAV and GBAS capability to spread the arrival noise over a much wider area.
There is no need to remain with 1950s technology and long streams of arriving aircraft following a single path over central London.
The current situation of arrival stacking and radar vectors to the ILS wastes tonnes of fuel. Using computer aided 4D NAV and the new technology would show that the Airport and the Industry are serious about being a good neighbour.