Originally Posted by
foxmoth
It is more to do with international connections, people do not want to fly into LHR then journey to STN/LGW etc to continue their journey.
Even with the airspace question though I would question why this is in GA?
Indeed in 2009 about 15% of Heathrow traffic was transit (same plane in and out) and 40% was transfer (change of plane). I see no reason for this not having increased or at least remained constant. So more than half of the customers for sure do not want to have to drag to another airport.