Junkers Ju 87 of carrying a bomb, but only if not carrying the rear gunner/radio operator as, even with the Jumo 210D, the Ju 87 was still underpowered for operations with more than a bomb load. All Ju 87 As were restricted to weapons (although during the Spanish Civil War missions were conducted without the gunner). The Ju 87 A-2 was retrofitted with the Jumo 210Da fitted with a two-stage supercharger. The only further significant difference between the A-1 and A-2 was the H-PA-III controllable-pitch propeller. By mid-1938, 262 Ju 87 As had been produced, 192 from the Junkers factory in Dessau, and
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