[yogybär]

Often, you have the Gruppe base at X while Staffeln or even smaller parts parts of it were based elsewhere. Are all your flightbooks from one Staffel?

Or you have one name for a base, but several small AFs in the surrounding. But 30km sounds a bit too much for this explanation.

Next explanation would be an "Absprungplatz". Example: II./JG52 was based in Leipzig / Romania in June summer 1944, but used to fly every morning to Iasi, using it as "Absprungplatz" in order to take off for combat flights in the direct vicinity.