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
Junkers J 2 fuselage directly below the stabilizer's leading edge root. The wings had at least three different airfoil changes between root and tip, and had sections of them electrically roll-welded for stronger, more continuous bonding for greater strength. The resulting aircraft was intended to be smaller than the J 1 demonstrator, but with its steel structure, it almost equalled the J 1's completed weight. One feature pioneered in the J 2 that would also be used in later all-metal monoplanes designed and built by Junkers in World War I, was a "unitized" forward fuselage structure, combining the engine mount, wing roots and