This is regularly done at BHX (from where I fly fairly often), and I'm sure it's happened to me somewhere else but can't remember where. But you do have to be flying OK. Also, for OK+ Silvers on OK flights , there is a relatively simple way of circumventing the "no access for silvers" rule in many airports, however it is a bit naughty and I'd never approve of this in public . Think about it and if you can't work it out PM me!