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 1 flown the "Flyer I" biplane in December 1903. On 12 December 1915, the aircraft made its brief maiden flight, flown by "Leutnant" Theodor Mallinckrodt of FEA 1, during which an altitude of almost was reached. Greater altitudes and performance was achieved during subsequent flights. By the end of January 1916, Junkers had been given a contract to further develop his all-metal concept, and the later Junkers J 2 single-seat fighter, which would never see frontline service, was the follow-on to the J 1. It is believed that the Junkers J 1 was not flown again after January 1916. In 1926