Re: 747 at Heathrow
I agree HD, and given hindsight then maybe it could have turned out differently as Gatwick would have been suitable, but there was a question as to whether Stansted would have been made IF the engines had all failed. The crew had flown past Heathrow, seen its suitable size and the CAVOK conditions and having few charts for UK airports decided that Heathrow was where they wanted to go.
Robin, look and see where the a/c actually declared the emergency, it was by Detling VOR which limited the possible airfields for diversion. Although its looks like faulty indications were to blame, at the time the crew were not aware of this and so potentially we were dealing with a powerless a/c so had to think extremely quickly to give the best chance of making an airport.