dspprune wrote: "I also live in the part of south east London allegedly "blighted" by aircraft noise according to Mr Stewart. Admittedly further along the approach path than Clapham, but right underneath one of the places where the Heathrow Directors seem to like to turn planes onto finals... "
There is no particular place at which we like to turn planes on to the ILS, nor do we consider the geography beneath when we issue heading instructions.. it depends on several factors - the amount of traffic, the wind and weather, the type of aircraft, what spacing is required on final approach, etc. Ideally we would be looking at a 10nm final approach and as Clapham is about 13 miles out you'll obviously see a few out there if we're busy. You might see more a/c late at night and early in the morning because we are not allowed to turn a/c on to final approach inside 10nm from touchdown during the night noise restrictions. That said, the further out they are the higher they will be, which should reduce noise.
The basic system hasn't changed much in the 30 years I've been a Heathrow Director except that we probably have more busy periods when the final approach becomes longer.