I'm also interested in this however more from the perspective of the 90/180 rule. I'm working for a 9H ACMI operator on a UK passport and I'm trying to figure out if I'll be able to work for any more than 3 months in 6 if the jet happens to be based in Europe.
I noticed, having popped into Europe for a few days, how they're now actively stamping and swiping passport's suggesting that they're now keeping track of movements in and out.
Any ideas if there's some kind of dispensation for crew or will I need to try and get something from the company and apply for a work permit?