During the 1930s, Nazi Germany had begun to field a class of "Schlacht" ("battle") aircraft, such as the Henschel Hs 123. Moreover, the experiences of German Condor Legion during the Spanish Civil War, against an enemy with few fighter aircraft, changed ideas about ground attack. Though equipped with generally unsuitable designs such as the Henschel Hs 123 and cannon-armed versions of the Heinkel He 112, their armament and pilots proved that aircraft were a very effective weapon, even without bombs. This led to some support within the Luftwaffe for the creation of an aircraft dedicated to this role, resulting in tenders for a new "attack aircraft". This led to the introduction (in 1942) of a unique single-seat, twin-engine attack aircraft, the slow-moving but heavily armored and formidably armed Henschel Hs 129 "Panzerknacker" ("Safecracker" /"Tank Cracker").