Junkers Ju 87 turned to the designs of Herman Pohlmann of Junkers and co-designer of the K 47, Karl Plauth. During the trials with the K 47 in 1932, the double vertical stabilisers were introduced to give the rear gunner a better field of fire. The main, and what was to be the most distinctive, feature of the Ju 87 was its double-spar inverted gull wings. After Plauth's death, Pohlmann continued the development of the Junkers dive bomber. The Ju A 48 registration D-ITOR, was originally fitted with a BMW 132 engine, producing 450 kW (600 hp). The machine was also fitted with
Hugo Junkers communist activist, as Managing Director of what remained of his business. Hugo Junkers is mainly known in connection with aircraft bearing his name. These include some he reluctantly developed for the German Empire during World War I, later in minor association with Anthony Fokker, as well as civil aircraft designs during the "interwar period" produced by "Junkers Flugzeugwerke" (Junkers Aircraft Works). Junkers died in 1935. The earliest all-metal post-World War I aircraft designs of both Andrei Tupolev — with his Tupolev ANT-2 two-passenger small aircraft of 1924 — and William Bushnell Stout's initial all-metal design, the Stout ST twin-engine torpedo