With the G variant, the ageing airframe of the Ju 87 found new life as an anti-tank aircraft. This was the final operational version of the Stuka, and was deployed on the Eastern Front. The reverse in German military fortunes after 1943 and the appearance of huge numbers of well-armoured Soviet tanks caused Junkers to adapt the existing design to combat this new threat. The Henschel Hs 129B had proved a potent ground attack weapon, but its large fuel tanks made it vulnerable to enemy fire, prompting the RLM to say "that in the shortest possible time a replacement of the Hs 129 type must take place." With Soviet tanks the priority targets, the development of a further variant as a successor to the Ju 87D began in November 1942. On 3 November, Milch raised the question of replacing the Ju 87, or redesigning it altogether. It was decided to keep the design as it was, but the power-plant was upgraded to a Junkers Jumo 211J, and two 30 mm (1.2 in) cannons were added. The variant was also designed to carry a 1,000 kg (2,200 lb) free-fall bomb load. Furthermore, the 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.