Junkers Ju 87 single mast mounted further forward on the "greenhouse" canopy, and much simpler, lighter-weight wheel "spats" used from the -B version onwards, discarding the transverse strut bracing of the "A" version's maingear design. This new design was again tested in Spain, and after proving its abilities there, production was ramped up to 60 per month. As a result, by the outbreak of World War II, the Luftwaffe had 336 Ju 87 B-1s on hand. The B-1 was also fitted with "Jericho trumpets", essentially propeller-driven sirens with a diameter of mounted on the wing's leading edge directly forward of the landing gear,
Junkers J 1 a series of fully cantilevered all-metal monoplanes. Upon the outbreak of the First World War in 1914, Junkers decided to direct his efforts towards projects which would have potential military value. During this era, the majority of aircraft designers were relatively conservative and, save for some isolated examples, no advancements were achieved; according to aviation historian Charles Gibbs-Smith, the pioneering work of Hugo Junkers was a notable exception. It was Junkers' efforts, along with those of collaborators such as engineers Otto Reuter, Otto Mader, head of Junkers' "Forschungsanstalt", and Hans Steudel, director of Junkers' structural materials and testing department that