Junkers Ju 87 withstand dives of . The Jumo 211D in-line engine was installed, replacing the R-1s Jumo 211A. Due to an increase in overall weight by , the Ju 87 R-2 was slower than the Ju 87 B-1 and had a lower service ceiling. The Ju 87 R-2 had an increased range advantage of . The R-3 and R-4 were the last R variants developed. Only a few were built. The R-3 was an experimental tug for gliders and had an expanded radio system so the crew could communicate with the glider crew by way of the tow rope. The R-4 differed
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