By October, the Germans had managed to assemble about in from Péronne to Hannescamps, 17 with about aircraft, flights () with about three bomber-fighter squadrons () and two independent flights with about to escort them, mainly of C-type, two-seater, armed biplanes and three fighter squadrons () with about "Jagdstaffel 2" () Hauptmann Oswald Boelcke) had been established at Bertincourt on 27 August and on 16 September, received new Albatros D.I and D.II fighters. The concentration of aircraft, particularly the superior fighters, enabled the Germans to challenge Anglo-French air superiority, at least for short periods.