RTM Boy
Of course it is entirely true that built-up areas cannot be avoided around LHR given that it is hemmed in on all sides, but the industry cannot ignore the potential consequences of relegating this aspect of safety to the point of a quick decision in the event of an emergency.
I think you are right NoD - a worst case scenario would strongly increase political pressure for Boris island to the point that LHR would be history. Indeed this may yet result from this incident if the AAIB blames BA procedures and questions the return to LHR from a public safety perspective - BA's case for a third runway will be seriously undermined. Such a situation would call into question the whole way maintenance is managed and carried out, which would mean very difficult questions for the CAA, BA and individuals managing and doing the work.
NoD and you have made valid points.
ATC handling an aircraft in emergency - even local ATC who know where urban areas are - will NOT reroute an aircraft recovering with an emergency as if they do so and the aircraft for whatever reason lands short it will be "their fault" for extending the aircraft track. There will have been a lot of work going on in the background making sure nobody got in the way of the emergency aircraft and that everyone involved or who 'needed to know' was aware of the problem(s). It would appear that from the declaration of the emergency to the safe landing and evacuation of the aircraft everyone successfully did as they should.
Inventing new low-risk procedures for those on the ground is NOT something for the flight-deck or the control room in an emergency; if they are necessary such procedures have to be developed, tested, simulated and briefed before flight and are only appropriate if the captain considers they are safe in a particular situation.
However, as NoD points out - doing as you should in aviation terms may not be politically acceptable. I have no doubt that there are going to be many hypothetical questions posed in the next few weeks thanks to video of an aircraft 'trailing smoke' over the centre of London. It is obvious that further development of Heathrow in many respects is hanging by a thread. Had this aircraft crashed at 6 miles finals all the logic of the arguments on this thread would be eclipsed by the political fall out and all the justifications for the return back to Heathrow - however valid - would be disregarded. Indeed there would also be impact worldwide on acceptance of airports like LGA where normal patterns are directly over major cities.
I do think the likelihood of the Heathrow 3rd runway must now be in increasing doubt.