By late August II./JG 26 was re-equipped with the new Fw 190 and introducing it to combat slowly and cautiously. Though the BMW 801 engines were still giving problems, the Gruppe's safety record was excellent and not a single Focke-Wulf was lost in non-operational accidents during the operational testing period.

With the Fw 190 the II./Gruppe would start a very successful period against the RAF Fighter Command, and during the rest of year the Gruppe would filed claims for no less than 36 enemy fighters for an own loss of two of their own, lost in air combat.

However, one of the Staffelkapitäns in the Gruppe, Lt. Kosse seems to have lost his "shooting eye" and it was not until 4 April 1942 that he managed to score his tenth abschusse, soon followed by another claim on 12 April, both Spitfires.

However a week later, on 19 he belly-landed this, machine W.Nr. 007 at St. Omer-Arques due to engine problems. The Fw 190 A-1 sustain 15 % damaged. Two weeks later Oblt. Kosse was sent packing by the Kommondore Adolf Galland to undertake a gunnery course at Grove in Denmark.

Upon completion, he was not to return to JG 26, as he was banished to JG 5. Perhaps Galland considered the poor results of one of his Staffelkapitäne and simply send him packing. Perhaps the reson was another, more personal, that his younger brother Oblt. Wilhelm-Ferdinand "Wutz" Galland transferred to Kosses old Staffel as Staffelführer, and the prospective new Staffelkapitän.

However Kosses Fw 190 was after repaired and refurbush taken over by the 6./JG 26. Here it was probably flown by Obfw. Wilhelm "Willi" Machenstedt as "Brown 14". This pilot was an "Old hare" a accomplished pilot who by this time had four confirmed victories under his belt.

Machenstedt would fly his last combat mission on 30 July 1943, hit by a B-17 return fire over Doetinchem. He would die the next day after being thrown out of his cockpit when his Fw 190 crashed. At this time he was accredited with a total of six confirmed victories.