Junkers Ju 87 the opening day of the offensive, Hans-Ulrich Rudel flew the only "official" Ju 87 G, although a significant number of Ju 87D variants were fitted with the 37 mm (1.46 in) cannon, and operated as unofficial Ju 87 Gs before the battle. In June 1943, the RLM ordered 20 Ju 87Gs as production variants. The G-1 later influenced the design of the Fairchild Republic A-10 Thunderbolt II, with Hans Rudel's book, "Stuka Pilot" being required reading for all members of the A-X project. The Soviet Air Force practice of harassing German ground forces using antiquated Polikarpov Po-2 and R-5 biplanes
Junkers J 2 aircraft in tests late in December 1916, to improve the future producibility of the advanced designs of the Junkers firm. Junkers J 2 The Junkers J 2 was the first all-metal aircraft intended as a dedicated military aircraft design, the first all-metal aircraft meant to be a fighter aircraft, and was the direct descendant of the pioneering J 1 all-metal aircraft technology demonstrator design of 1915. Only some two weeks after the last known recorded flight, on 18 January 1916, of the J 1 "technology demonstrator" design of 1915, the Junkers firm had impressed "Hauptmann" Felix Wagenführ, head of "IdFlieg"