Junkers Ju 87 of 500 sorties per day and caused heavy losses among Soviet forces, losing an average of only one Stuka per day. The Battle of Stalingrad marked the high point in the fortunes of the Junkers Ju 87 Stuka. As the strength of the Soviet Air Forces grew, they gradually wrested control of the skies from the Luftwaffe. From this point onward, Stuka losses increased. The Stuka was also heavily involved in Operation Citadel, the Battle of Kursk. The Luftwaffe committed I, II, III./St.G 1 and III./StG 3 under the command of Luftflotte 6. I., II, III. of StGs 2 and
Junkers J 2 spin on 23 September 1916 in one of the J 2s, and this event, combined with the substandard climbing performance of the J 2 series of test aircraft, caused "IdFlieg" to withdraw any further governmental support (effectively ending the J 2's contract) for the Junkers firm's advanced monoplane designs until a lighter metal, such as duralumin, was selected for such designs. The first attempt to use duralumin for airframe construction by the Junkers firm was the never-completed J 3 mid-wing, rotary engine-powered, aluminum tubing fuselage single-seat monoplane design, of which only the corrugated sheet duralumin-covered wing structures and "bare" tubular