Originally Posted by
BA1A
I haven't done a domestic to international connection since the days of T1 to T4 (as I usually don't trust them so just travel down the night before) but IIRC I didn't have to go through a second security check at T4 after getting my BP checked at T1 flight connections and getting on the bus
, it just dropped me off at the terminal and I entered straight in the departure shopping area.
...
why did I never have to do this from T1 to T4 or is my memory going?
If you connect
from a domestic flight, the theory is that you have already been security screened in the UK, to UK standards, so you don't need to be security screened again. So when connecting from T1 to an international flight, you would have been routed into the T1/2 Flight Connections Centre after the security screening point. In contrast, any non-Ireland international arrival into T1 would go into the FCC before the security screening point. IIRC, I think that all Ireland arrivals had to go landside and then come back to airside via a normal landside->airside security screening point. By the time you reached the bus to go to T4, it would therefore have contained a mixture of domestic arrivals not screened at LHR, and international arrivals screened again at LHR.