Hans-Ulrich Rudel, a Stuka ace, had suggested using two 37 mm (1.46 in) Flak 18 guns, each one in a self-contained under-wing gun pod, as the Bordkanone BK 3,7, after achieving success against Soviet tanks with the 20 mm MG 151/20 cannon. These gun pods were fitted to a Ju 87 D-1, W.Nr 2552 as "Gustav the tank killer". The first flight of the machine took place on 31 January 1943, piloted by Hauptmann Hans-Karl Stepp.[66] The continuing problems with about two dozens of the Ju 88P-1, and slow development of the Hs 129 B-3, each of them equipped with a large Bordkanone BK 7,5 cm (2.95 in) cannon in a conformal gun pod beneath the fuselage, meant the Ju 87G was put into production. In April 1943, the first production Ju 87 G-1s were delivered to front line units.[66] The two 37 mm (1.46 in) cannons were mounted in under-wing gun pods, each loaded with a six-round magazine of armour-piercing tungsten carbide ammunition. With these weapons, the Kanonenvogel ("cannon-bird"), as it was nicknamed, proved spectacularly successful in the hands of Stuka aces such as Rudel.
Only a handful of production Gs were committed in the Battle of Kursk. On 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.[70] The G-1 later influenced the design of the A-10 Thunderbolt II, with Hans Rudel's book, Stuka Pilot being required reading for all members of the A-X project
Source:
Wikipedia
En.wikipedia.org