World War II in Europe began on Friday 1 September 1939 when German forces invaded Poland. On 6 December 1939, Tonne was posted to 3. Staffel of Jagdgeschwader 53 and received the Iron Cross2nd Class on 18 April 1940. Tonne claimed his first aerial victory over a Royal Air ForceBristol Blenheim twin-engined bomber over Sedan from either No. 21, No. 107 or No. 110 Squadron on 14 May 1940 during the Battle of France. On that mission, he was also shot down near Bouillon. He bailed out landing in enemy territory. However, he returned safely to his own lines, uninjured. Over England and the Channel he was to gain a further three victories by the spring of 1941.
On 1 July, Tonne was appointed Adjutant of I./JG 53. Tonne participated in the invasion of the Soviet Union. In June and July 1941, he scored eight further victories. In December 1941, I./JG 53 was transferred to the Mediterranean theatre. On 24 January 1942, Tonne was appointed Staffelkapitän of 3./JG 53. Tonne flew 116 combat missions over Malta, without adding to his victory total, before being transferred back to the Eastern Front. From 31 May 1942 to 29 September 1942, Tonne flew 155 combat missions and shot down 88 aircraft on the Eastern Front. Oberleutnant Tonne was awarded the Knight's Cross of the Iron Cross on 6 September 1942 following his 54th victory. The Oak Leaves were awarded on 24 September for 101 victories. In November 1942, Tonne led 3./JG 53 to North Africa. He gained his first victory in this theatre on 26 December 1942 shooting down a United States Army Air ForcesP-38 Lightning twin-engine fighter. He specialised in shooting down Supermarine Spitfire fighters claiming ten of the type in a short time. Tonne flew 82 combat missions and claimed 21 victories over Tunisia. Tonne was killed in a flying accident over the airfield at Protville, Tunisia on 20 April 1943 in his Messerschmitt Bf 109 G-6 /R1. He was promoted to Major posthumously. Tonne was credited with 122 victories claimed in 641 missions. He scored 26 victories over the Western Front, including 16 Supermarine Spitfire. 10 of his 96 victories claimed over the Eastern Front were Il-2 Sturmoviks.
Summary of career
Aerial victory claims
Matthews and Foreman, authors of Luftwaffe Aces — Biographies and Victory Claims, researched the German Federal Archives and found records for 120 aerial victory claims, plus six further unconfirmed claims. This figure of confirmed claims includes 118 aerial victories on the Eastern Front and two on the Western Front, including one four-engined bomber. Victory claims were logged to a map-reference, for example "PQ 49293". The Luftwaffe grid map covered all of Europe, western Russia and North Africa and was composed of rectangles measuring 15 minutes of latitude by 30 minutes of longitude, an area of about. These sectors were then subdivided into 36 smaller units to give a location area 3 × 4 km in size.