The aircraft they are in is a Canadian built, Canadair North Star - 4 engine airliner. After they are released by the East Germans, the aircraft shown departing is a Convair 240 - 2 engine airliner.
After the flight crew is taken into the holding room by the local political officers, Karin lights up a cigarette in spite of the Rauchen Verboten (No Smoking) sign clearly visible on the wall behind her. The military guard doesn't say a word as she continues to smoke.