Originally Posted by
FlyerLX
.... I see... So in that case, why the difference in traffic from B to A (definitely security) and Z to A (security only from non-clean) ? After all, an arriving flight from, say, USA can arrive on B or on Z, can’t it...??
A flight from USA can arrive at B or Z, and even C ( but C is closed at the moment ) and the fact whether you would clear security or not would depend on your arrival gate.
Pre-COVID, there was a B60->Z13 airside shuttle for passengers arriving from a clean destination at Non-Schengen B to not re-clear security but that is discontinued since COVID.