Originally Posted by
corporate-wage-slave
Is Aer Lingus still doing a bus to T5? If so, and you can get on that bus then you can exit via the UK Border in T5, but obviously you can't go to Flight Connections without a relevant boarding pass. Not possible with checked luggage, or rather it would go to the wrong place.
They were doing it last July when I was connecting for a flight to NRT, but I can't remember if they asked for a boarding pass before allowing me on the connection bus!