Check to see if your airline has a reciprocal agreement. If so, what I did was to just go to the ticket counter and request the jumpseat. Need passport, and to pay the Int'l taxes. They checked with HQ to make sure there was an agreement, and handed me a boarding pass. I waited at the gate, said hello to the crew and asked the captain if I could j/s. All there were very nice, and it's a great way to cross the pond.