serving as a technical officer with the Geschwaderstab (headquarters unit), was replaced in this capacity by Leutnant Walter Horten on 14 December. Serving with 7. Staffel (7th squadron) of JG 26, he crashed his Messerschmitt Bf 109 E-3 (Werknummer 1202—factory number) during takeoff at Chièvres Airfield on 27 May. At the time 7. Staffel was headed by Oberleutnant Georg Beyer. III. Gruppe (3rd group), to which his squadron was subordinated, was commanded by Major Ernst Freiherr von Berg who was replaced by Hauptmann Adolf Galland on 11 June. Mietusch claimed his first aerial victory during the Battle of France on 31 May 1940. In combat with the fighters from No. 213 and No. 264 Squadron from the Royal Air Force (RAF), he shot down a Hawker Hurricane fighter near Dunkirk. On 8 June, Mietusch made a forced landing in his Bf 109 E-1 (Werknummer 2746) behind enemy lines. He was shot down in combat with a Hurricane near Neufchâtel. Although uninjured in the landing, he was shot by a French civilian and taken prisoner of war. Following the armistice of 22 June 1940, he was sent to hospital in Germany. Malta, Balkans and North Africa in 1941 On 22 January 1941, 7. Staffel received orders to relocate to Sicily in support of X. Fliegerkorps, under the command of General der Flieger (General of the Flyers) Hans Geisler, for actions against the strategically important island of Malta. With the opening of a new front in North Africa in mid-1940, British air and sea forces based on the island could attack Axis ships transporting vital supplies and reinforcements from Europe to North Africa. To counter this threat the Luftwaffe and the Regia Aeronautica (Italian Royal Air Force) were tasked with bombing raids in an effort to neutralise the RAF defences and the ports. That day the unit and a 40-strong detachment of ground crews departed Wevelgem. Following a brief stopover in Rome, 7. Staffel arrived in Gela on Sicily on 9 February 1941. There, the unit received factory new Bf 109 E-7 aircraft. Mietusch claimed his first victory in the Siege of Malta on 26 February over a No. 261 Squadron Hurricane south of Malta. He became a fighter ace on 22 March, taking his total to five aerial victories. In combat north of Malta, Mietusch had shot down two No. 261 Squadron Hurricanes. On 5 April, 7. Staffel moved to Grottaglie