Junkers Ju 87 armoured protection of the Ilyushin Il-2 "Sturmovik" - a feature pioneered by the 1916-17 origin Junkers J.I all-metal sesquiplane of World War I Imperial Germany's Luftstreitkräfte - was copied to protect the crew from ground fire now that the Ju 87 would be required to conduct low level attacks. 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
Junkers J 2 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" "Prüfanstalt und Werft der Fliegertruppe" ("Test Establishment and Workshop of the Aviation Troops") department, enough for him to contract the