Junkers Ju 87 but the Ju 87 continued to be used as a night nuisance-raider until the end of the war. The second prototype had a redesigned single vertical stabiliser and a Junkers Jumo 210 A engine installed, and later the Jumo 210Da. The first A series variant, the A-0, was of all-metal construction, with an enclosed cockpit under a "greenhouse" well-framed canopy; bearing twin radio masts on its aft sections, diagonally mounted to either side of the airframe's planform centreline and unique to the -A version. To ease the difficulty of mass production, the leading edge of the wing was straightened out
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