Dusseldorf transfer and transit visas
 

I was wondering if somebody could kindly clarify what went wrong on our recent flight from Bangkok to Birmingham, as nobody a Eurowings seems to know.

We recently tried to transfer at Dusseldorf on a flight from Bangkok to Birmingham. On reaching a security check, my girlfriend, a Thai national, wasn't allowed to pass because she didn't have a transit visa. Eventually, we were escorted to the plane but the pilot decided to leave without us, even though the border security officer had repeatedly called the plane and been assured that it would wait for us. We had to get another connection to London 4 hours later and a train home. Our bags were also lost for 5 days.

I've repeatedly called Eurowings, but nobody knows why this happened.

Do you have to go through security when transferring, or did we miss the sign for transfers? On our return flight, the cabin crew member who checked in our bags suggested that we had gone the wrong way and had tried to enter arrivals. I'm fairly certain this wasn't the case as when I asked the the border security officer if we'd gone the wrong way he said no. He said something about the airline hadn't emailed security to obtain her transit visa. Is this what is supposed to happen? As as far as I'm aware, Thai nationals don't need to apply for a transit visa.

There are some non-Schengen gates at DUS that are at the end of the "A" and "B" piers. These can only be reached by entering Germany (Schengen zone): https://www.dus.com/en/flights/transferring

Your girlfriend would have required a Schengen visa to transfer from C non-Schengen to A or B non-Schengen via A and/or B Schengen (not a transit visa, which is what some unfortunate people require to simply transit, even if they remain in the non-Schengen zone at all times).

Were both flights on one ticket? If so, the airline did you fly into DUS on? They should have made arrangements with Bundespolizei prior to arrival into DUS if passenger did not have a Schengen visa and required one to transit.

There is always a small risk when transferring in a country where you need a visa to enter. Quite often people get stuck in the transit zone due a missconnection and can't leave the transit area to stay at a hotel outside for one night. That's the reason why some countries require a regular visa even for just transferring ( and I don't mean the Schengen transfer visa).

Anyways, Tom Tulpe explained pretty well want went wrong. Arriving and departure gate were both non-Schengen gates but are separated by the Schengen area. Probably no one at Eurowings thought of this.

Yes, this was my immediate thought as well. I doubt you'll get much sympathy from EW (rightly or wrongly). Welcome to FT!

As the BKK-flight is operated in/out of Terminal C, they must have connected on EW to BHX.
BE would have been the only other option, but they are always at the C5x-bus gates.

EW to BHX operates out of Terminal A (Non-Schengen), so TWOV would have been possible.
Seems like EW did not inform Klüh at DUS, about that request and therefore they were not picked up at the ACFT.