Junkers Ju 87 with several auxiliaries. The Polish naval units trapped in the Baltic were destroyed by Ju 87 operations. Once again, enemy air opposition was light, and the "Stukawaffe" (Stuka force) lost 31 aircraft during the campaign. Operation Weserübung began on 9 April 1940 with the invasions of Norway and Denmark. Denmark capitulated within the day; Norway continued to resist with British and French help. The campaign was not a "Blitzkrieg" of fast-moving armoured divisions supported by air power as the mountainous terrain ruled out close Panzer/Stuka cooperation. Instead, the Germans relied on paratroops transported by Junkers Ju 52s and specialised ski
Hugo Junkers in Dessau. The iron wings were patented one year later. Junkers had a wind tunnel built and invented a hydraulic brake. He had far-sighted ideas of metal aeroplanes and flying wings, but the necessities of the war held him back. During World War I, the government forced him to focus on aircraft production. In 1915, he developed the world's first practical all-metal aircraft design, the Junkers J 1 "Blechesel" (Sheetmetal Donkey), which survived on display in Deutsches Museum in Munich until World War II. His firm's first military production design in 1916–17 was the armored-fuselage, two-seat, all-metal sesquiplane known by