夜間戦闘機
In November 1941, Schnaufer was posted to the II. "Gruppe" of "Nachtjagdgeschwader" 1 (II./NJG 1—2nd group of the 1st Night Fighter Wing) at the time based at Stade near Hamburg. Here, Schnaufer was assigned to the 5. "Staffel" (5./NJG 1—5th squadron of 1st Night Fighter Wing). The Bf 110's of II./NJG 1 at the time were not equipped with airborne radar such as the "Lichtenstein" radar. Night fighter intercept tactics had matured since their early beginnings in July 1940, and II. "Gruppe" had already been credited with 397 victories. Missions against enemy bombers at the time were usually flown by means of ground-controlled interception, although the Luftwaffe was already experimenting with airborne radar. This air defence system, consisting of a series of radar stations with overlapping coverage, layered three deep, was conceived by "Generalleutnant" (lit. Lieutenant General; equivalent to Major General) Josef Kammhuber and was organised in the so-called Kammhuber Line. Conceptually, the system was based on a combination of ground-based radar stations, search lights and a "Jägerleitoffizier" (fighter pilot control officer). The "Jägerleitoffizier" had to vector the airborne night fighter by means of radio communication to a point of visual interception of the illuminated bomber. These interception tactics were referred to as the "Himmelbett" (canopy bed) procedure.