At the outbreak of World War II Milch, now with the rank of general, commanded "Luftflotte 5" during the Operation Weserübung in Norway. Following the defeat of France, Milch was promoted to Generalfeldmarschall (field marshal) during the 1940 Field Marshal Ceremony and given the title Air Inspector General. As such, Milch was in charge of aircraft production. Milch cancelled production of the ineffective and dangerous Me 210 and He 177 and put them back in development. Under his direction, aircraft production focused on mass production of the tested and tried models. Production levels doubled in the summer of 1943 in comparison with the winter of 1941–1942. Tooze comments: "For the first time, the German aircraft industry was able to achieve substantial economies of scale. The resources pumped into the Luftwaffe in 1940–41 were now concentrated in mass assembly." To achieve this level of mass production, the Armaments Ministries and the industry cooperated with the SS to procure labour from the concentration camps. Due to Milch's connections with the SS, the Luftwaffe had an advantage in obtaining slave labour. In order to increase the quantity, Milch also made some sacrifices in quality, notable in the case of the Bf 109. When the US Air Force began to directly challenge the fighter forces of the Luftwaffe, the cost of Milch's decisions was shown. Especially, the handling of the Bf 109 G was so bad that it became, in the words of Tooze, "little more than death traps".