If arriving in the Schengen zone without valid travel document(s) or other circumstances applicable for entry into the Schengen zone, the detention ordinarily occurs in the first instance in the first Schengen country on the itinerary -- in this case, that would be Germany. That's if the airline even allows the passenger to fly to Germany.
Originally Posted by
RichardInSF
Welcome to FT, CrazyTalk! It is correct that you will enter into Schengen territory at FRA on this routing. But where is your GF flying from?
Sounds like Russia or some place from which the arrival date in the Schengen area would be the same as the departure date from the relevant non-Schengen country -- or perhaps it's a mileage run.