I am still trying to find out if GLA offers that transit facility or if I have to out through arrivals and back through departures.
Thank you for you reply, Gagravarr
You’re very kind. I’m a UK Citizen and regularly connect from the US when in the UK so I'm familiar with the red/blue/green channels when connecting. However, I usually connect in LHR, MAN, EDI and BHX. I’ve only flown domestic-to-international from GLA rather than the other way around.