Originally Posted by
Air Rarotonga
Yes, its doable if flights were on-time... You need to pass EU passport emigration and then take the train from Terminal A to E.
Schengen immigration. Has nothing to do with EU. Some EU members are part of Schengen some are not. Some Non EU members are part of Schengen. (like Switzerland)
A flight from LHR gets the same immigration treatment as one from NYC. One from MAD is "domestic" since both Spain and Switzerland are Schengen members.