When I say transit zones, which some also call sterile zones, I mean an airport that has the capability of you to get off your inbound flight and go to the outbound one without having to ever see an immigration officer. When I flew to CDG it was like that. However, Gatwick, regardless of whether you booked connecting flights through the same airliner or not, everyone had to be processed through an immigration officer. I am wondering if any more MAJOR airports are like Gatwick, in that, no one can transit through without manual inspection. This is interesting to me