Werfer-Granate 21

The Werfer-Granate 21 rocket launcher, also known as the BR 21 (Bordrakete), was the first on-board rocket in Luftwaffe service. The Werfer-Granate 21 was developed by Rheinmetall-Borsig and introduced into service in mid 1943.

By mid 1943 Allied bombers started regularly bombing the German territory. At that time Luftwaffe had no cannons or rockets that could be effectively used against heavy four-engined bombers flying in the combat box formation. The fast solution was found in modifying a very effective ground-launched rocket, the 21 cm Nebelwerfer 42 infantry barrage rocket projectile, into an air-launched variant. The original rocket was equiped with a powerfull warhead that warranted destroying a heavy bomber even without direct hit. The air-to-air modification of the Nebelwerfer 42 was designated as the Werfer-Granate 21.

Werfer-Granate 21 rockets enabled the German pilots to attack the bomber targets out to a distance of 1,200 metres. While a single fighter's payload of two or four such rockets was extremely unlikely to hit an aerial target, a mass launch by an entire fighter squadron (12-16 aircraft) would likely score two or three hits, about 15% accuracy. The rocket's huge blast radius compensated for inaccuracy, and even a non-lethal hit on a bomber by a showering of shrapnel would have psychological effects and perhaps cause it to take evasive maneuvers that would drive it from the protection of its fellows.

The Werfer-Granate 21 were also used against ground targets from late 1943 onwards.