Approach control service (APP) was provided by two RAPCONs, one at Spangdahlem for the Büchel, Hahn, Spangdahlem and Bitburg bases in the Eifel area (Spangdahlem Control) and another at Sembach for the Ramstein, Sembach and Pferdsgfeld bases in the Palatinate area (Sembach Control). 2015, Frank W. Fischer, International Advisory Group Air Navigation Services, German Air Traffic Control During The Cold War: The Story of Rhein Control, p. 28