Following on from Nighthawk's amusing yet depressing tale of BA/BAA competence at LHR T5, we were discussing the issues of segregating and comingling international and domestic pax.
Obviously BAA decided they wanted to comingle them because they are after all trying to run a shopping mall here. Optimising of the airport sideshow must naturally come second.
In doing so, someone from the Home Office dreamt up this colourful scenario. A terrorist, barred from entering Britain, books a transfer flight through LHR T5. His legal yet insidious buddy, resident in the country, books a domestic flight that coincides with the transfer of the terrorist. The terrorist arrives at the airport. Because he's connecting internationally, his passport isn't checked (apparently, though I want to know what those desks were during the trials when I pretended to be on an international connection). He enters the departure lounge without anyone knowing he shouldn't be here. He meets his buddy and picks up his boarding pass. The buddy pretends to chicken out citing fear of flying and leaves the airport. The terrorist then takes the domestic flight instead and can then leave the destination without hassle. He has entered Britain. Dun, dun, dun, dun!
That's why all domestic pax are photographed on passage through security so their identity can be verified when boarding. This creates the peverse situation, as Nighthawk found out, where domestic pax are the ones who make security awkward.
Wouldn't this be sovled if all pax were checked on arrival whether or not they were connecting? That why the terrorist would be caught then and there. (I am assuming the Home Office isn't stupid enough to allow banned terrorists to pass freely through our airports, a naive assumption I admit.)