At Jesau, the "Gruppe" began upgrading their aircraft to the Bf 109 F-4. On 14 April, II. "Gruppe" was ordered to Pilsen, where they finished the conversion. The unit then moved to Wien-Schwechat on 24 April before flying to Zürichtal, present-day Solote Pole, a village near the urban settlement Kirovske in the Crimea. There II. "Gruppe" participated in Operation Trappenjagd, a German counterattack during the Battle of the Kerch Peninsula, launched on 8 May.