Anti-bomber He-177 which was proposed to use Wfr.Gr.42 rockets
Five He 177 A-5s were experimentally equipped in January 1944 with batteries of 33 obliquely mounted 21 cm (8¼ in) calibre rocket mortar tubes, physically similar to the Werfer-Granate 21 single units already in use with single and twin-engined Luftwaffe fighters for bomber destroyer missions, and also likely to have been similarly derived from components of the Nebelwerfer infantry barrage rocket system. The nearly three dozen launch tubes placed in a Greif's fuselage in such a manner was meant to create the Grosszerstörer ("Big Destroyer") flying battleship, designed to break up and destroy the tight combat box defensive formations used by USAAF daylight bombers over Germany. The bomb bays and fuselage-housed auxiliary fuel tanks were removed on these aircraft in order to provide space for the spin-stabilized 21 cm (8 in) rockets and their launch tubes. The tubes were inclined to fire upward at an angle of 60° to the horizontal, and slightly to starboard. The tubes could be fired individually, simultaneously, or in two salvoes of 15 and 18. Tests with fixed balloon targets showed the potential of this system, and limited operational trials against US Eighth Air Force bomber streams were authorized. The aircraft were operated by Erprobungskommando 25, flying out of the Baltic coastal Erprobungstelle facility at Tarnewitz. The intended mode of operation required the Grosszerstörer He 177s to follow the enemy bomber formations, passing below (as with a Schräge Musik cannon fitment) and to port of the target, maintaining a difference of altitude of 2,000 m (6,560 ft) beneath the targets at the time of the attack. A few trial daylight operations were flown but no contact was made with Allied bomber formations.