Junkers Ju 87 its pilot, Captain Mieczysław Medwecki, was killed. In air-to-air combat, Ju 87 formations were well protected by German fighter aircraft and losses were light against the tenacious, but short lived opposition. The Ju 87s reverted to ground attack missions for the campaign after the opening air attacks. Ju 87s were involved in the controversial but effective attacks at Wieluń. The lack of anti-aircraft artillery in the Polish Army magnified the impact of the Ju 87. At Piotrków Trybunalski I./StG 76 and I./StG 2 destroyed a Polish infantry division de-training there. Troop trains were also easy targets. StG 77 destroyed one
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