21 cm Nebelwerfer 42 The 21 cm Nebelwerfer 42 ( 21 cm NbW 42 ) was a German multiple rocket launcher used in the Second World War . It served with units of the " Nebeltruppen " , the German equivalent of the American " Chemical Corps " . Just as the " Chemical Corps " had responsibility for poison gas and smoke weapons that were used instead to deliver high - explosive s during the war so did the " Nebeltruppen " . The name " Nebelwerfer " is best translated as " smoke - thrower " . It saw service from 1942 – 45 in all theaters except Norway . It was adapted for aerial combat by the Luftwaffe in 1943 . Description . The " 21 cm NbW 42 " was a five - barreled multiple rocket launcher mounted on the towed carriage derived from that of the 3 . 7 cm PaK 36 anti - tank gun . A pivoting stabilizer was added to the front of the carriage to steady the launcher when firing . The " 21 cm Wurfgranate ( thrower - shell ) 42 " rockets were spin - stabilized , electrically - fired and only had high - explosive warheads . The rocket nozzle assembly contained 22 orifices evenly spaced around the rim of the nozzle with the orifices set an angle of 16° from the axis of the rocket to give the rocket clockwise rotation . The rockets had a prominent exhaust trail that kicked up a substantial amount of dust and debris , so the crew had to seek shelter before firing . This meant that they were easily located and had to displace quickly to avoid counter - battery fire . The rockets were fired one at a time , in a timed ripple , but the launcher had no capability to fire single rockets . The rockets could be fitted with either impact or delay fuses as necessary . Liner rails could be fitted to allow the launcher to use " 15 cm Wurfgranate 41 " rockets with their HE , smoke and poison gas warheads . Despite the improved aerodynamics of the " Wgr . 42 " rocket over the " 15 cm Wgr . 41 " it proved to have similar dispersion problems ; notably an area long and because of uneven burning of its propellant . Army use . The " 21 cm NbW 42s " were organized into batteries of six launchers with three batteries per battalion . These battalions were concentrated in independent " Werfer - Regiments " and " Brigades " . They saw service on the Eastern Front , North Africa , Italian Campaign and the defence of France and Germany from 1942 — 45 . Luftwaffe use as the " Werfer - Granate 21 " . 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 of 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 fit 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 used on an experimental bomber destroyer version of the He 177 heavy bomber , known as the " Grosszerstörer " , which proposed using upwards of thirty - three of the launch tubes , firing upwards from the mid - fuselage ' s bomb bay area at a 60° angle ( similar to the effective " Schräge Musik " night fighter autocannon fitment ) and firing slightly to starboard out the dorsal fuselage surface , flying two kilometers below the USAAF combat box formations – a few trial intercepts were attempted , without contact with USAAF bombers , and was doomed to fail from the swarms of American fighters protecting the bombers .