troops nicknamed the weapon Screaming Mimi from the noise of its rockets. Luftwaffe use as the Wfr. Gr. 21 (BR 21) rocket launcher The rocket was adapted for air-to-air use by the Luftwaffe in 1943 with a time fuse and a larger warhead as the Wfr. Gr. 21, or BR 21 (for Bordrakete 21, as seen on German manuals) to disrupt Allied bomber formations, particularly the Eighth Air Force's combat box formations, and make them more vulnerable to attacks by German fighters while staying outside the range of defensive fire from the bombers. Single launch tubes were fitted under each wing of the Bf 109 and Fw 190 single-engined fighters, and two under each wing on the Bf 110 twin-engined fighters. The earliest known attack against American bombers with the underwing rockets was made on July 29, 1943, by elements of both JG 1 and JG 11, during American strategic bombing attacks on both Kiel and Warnemünde. Photographic evidence indicates that the Hungarians fitted three tubes under each wing of some of their twin-engined Me 210 Ca-1 heavy fighters. However, the high drag caused by the launchers reduced the speed and manoeuvrability of the launching aircraft, which could be lethal if Allied fighters were encountered. Also, the launch tube's under-wing mounting setup, which usually aimed the projectile at about 15° upwards from level flight to counter the considerable ballistic drop of the projectile in flight after launch, added to the drag problem. The American nickname for the 21 cm rockets was "flaming baseballs" from the fireball-like appearance of the projectiles in flight. The Messerschmitt Me 410 Hornisse heavy fighter was known to have sometimes been fitted with the Bf 110's quartet of launchers for the Wfr. Gr. 21 rockets, but one tested an experimental installation of six launching tubes, similar in appearance to the 15 cm Nebelwerfer 41's half-dozen carriage-mounted tubes, in the Me 410's under-nose weapons bay. The tube assembly, with their axis angled upwards at 15° (as the underwing mountings were angled) was intended to rotate, as a revolver pistol's cylinder would, as each rocket to be fired was launched singly from the exposed tube at the bottom of the aircraft's nose. A test flight was made on 3 February 1944, but the concept proved to be a failure as the rockets' exhaust substantially damaged the aircraft. A similar adaptation of the 21 cm Nebelwerfer's components were also