HD - this question may just be too involved to provide a brief explanation so I'll try to phrase as succinctly as possible.
When there is a runway switch at LHR, how do you prevent aircraft making their way to final approach for the 'wrong' (no longer in use) runway? Do you have to hold everyone in the holding stacks while the last landings 'filter out'? Or is it possible to synchronise the change-over while aircraft continue to leave the stacks?
Since the airport has a departure/arrival every minute or so, is there any sort of delay while the switch-over happens?
Appreciate this may be complex but very grateful for any explanation you can offer!
Nick