The Hansa-Brandenburg W.12 was a German biplane fighter floatplane of World War I. It was a development of Ernst Heinkel's previous KDW, adding a rear cockpit for an observer/gunner, and had an unusual inverted tailfin/rudder (which instead of standing up from the fuselage, hung below it) in order to give an uninterrupted field of fire. The W.12s (under the Naval designation C3MG) served on the Western Front, based at the Naval air bases at Ostend and Zeebrugge. The aircraft had some success, and one shot down the British airship C.27.