As the battle on the Eastern Front progressed, the Wehrmacht found itself struggling to deal with the increasingly tougher armored opposition from the Soviet, particularily the KV heavy tank series. This resulted into an idea of mounting a large anti-tank cannon on an aircraft in order to destroy them by firing at its weaker roof armor. One such extreme case is the Henschel Hs 129 B-3 a modified version of the Hs 129 series of attackers. Given the relative robustness of the Hs 129's airframe, a decision was made to mount a huge 75 mm BK 7.5 anti-tank cannon, a modified version of the famous PaK 40 gun, under its fuselage. After 25 aircraft was built on August 1944 and deployed a month later, the B-3 were proven to be effective in its intended role, even against the new IS heavy tank series. Due to the low production run, however, the He 129 B-3 have little effect for the overall war effort.

Introduced in Update 1.37, the Hs 129 B-3 is an unusual variant of the Hs 129 family. Affectionately nicknamed the "duck" by the community, the B-3 was designed solely as a "can opener" attack aircraft and therefore forwent almost all of its anti-air firepower in favor of a huge 75 mm BK cannon. Being based on an anti-tank gun, the BK has exceptional penetration even with the stock belt, and is capable of penetrating every tank in the game via shots on the roof. However, since the BK cannon has only 12 rounds available, care must be taken to make each shot count. Since the plane itself is quite slow and sluggish, it won't take long for the enemy fighters to reach and intercept you. This, combined with the plane's poor anti-air capabilities, making it the literal "sitting duck" in air-to-air combat.