Friedrich-Karl "Tutti" Müller (25 December 1916 – 29 May 1944) was a German Luftwaffe military aviator and wing commander during World War II. As a fighter ace, he is credited with 140 aerial victories claimed in more than 600 combat missions. He claimed eight aerial victories during the Battle of France, 89 on the Eastern Front, and further 43 victories against the Western Allies in the Mediterranean Theatre and in Defense of the Reich, including 24 four-engined bombers. He was "ace-in-a-day" four times, shooting down five or more aircraft on a single day.

Born in Berlin-Lichterfelde, Müller grew up in the Weimar Republic and Nazi Germany. Following graduation from school, he volunteered for military service in the Wehrmacht in 1936. Initially serving with the Army, he transferred to the Luftwaffe in 1938. He completed flight training in 1939 and was posted to Jagdgeschwader 53 (JG 53—53rd Fighter Wing). Flying with this wing, Müller claimed his first aerial victory on 27 May 1940 during the Battle of France. He also fought in the Battle of Britain, Operation Barbarossa, the German invasion of the Soviet Union, and in Siege of Malta before again transferring to the Eastern Front in 1942. There, he claimed his 100th aerial victory and was awarded the Knight's Cross of the Iron Cross with Oak Leaves on 23 September 1942.

In November 1943, Müller was given command of I. Gruppe of JG 53 which was operating in Mediterranean Theatre. In February 1944, he transferred to Jagdgeschwader 3 "Udet" (JG 3—3rd Fighter Wing), initially commanding the IV. Gruppe, fighting in defense of the United States Army Air Forces daytime attacks. In April, he was appointed Geschwaderkommodore (wing commander) of JG 3 and claimed his 140th aerial victory on 12 May. Müller was killed in a landing accident on 29 May 1944. Posthumously, he was promoted to Oberstleutnant (lieutenant colonel).

Early life and career Müller, who was nicknamed "Tutti", was born on 25 December 1916 in Berlin-Lichterfelde, at the time in the Kingdom of Prussia of the German Empire. He was the son of a public accountant (Rendant). From 1924 to 1927, he attended the 14. Gemeindeschule (14th elementary school), from 1927 to 1932, the Oberrealschule Lichtenberg, a secondary school, and graduated from the 2. Städtische Mittelschule (2nd municipal middle school) in 1934, attaining the Mittlere Reife (Middle Maturity). While at school, Müller was also a member of the Hitler Youth in Potsdam. He joined the military service of the Wehrmacht on 17 October 1936, initially serving with 2. Kompanie (2nd company) of Pionier Bataillon 42 (42nd pioneer battalion). On 25 June 1937, he became a Fahnenjunker (cadet), and starting on 16 October 1937, was trained at the Kriegsschule in Munich. There, he was promoted to Fähnrich (officer candidate) on 26 March 1938, effective as of 1 March 1938.

On 28 April 1938, officially effective as of 1 July, Müller was transferred to the Luftwaffe at Bad Aibling where he was promoted to Oberfähnrich (senior officer candidate) on 30 June 1938, effective as of 1 June 1938. On 1 July, Müller was then sent to the Fliegerersatz-Abteilung (Replacement Detachment) 17, renamed to Fliegerersatz-Abteilung (Replacement Detachment) 62 on 11 November 1938, based at Quedlinburg for further training. At Quedlinburg, he was promoted to Leutnant (second lieutenant) on 8 November 1938, effective as of 1 September 1938. His flight training began on 1 March 1939, at first at Oldenburg, and on 17 July 1939 at the Jagdfliegerschule (fighter pilot school) at Werneuchen. Following flight training, Müller was posted to the III. Gruppe (3rd group) of Jagdgeschwader 53 (JG 53—53rd Fighter Wing) on 3 October 1939, there he was assigned to the 8. Staffel (8th squadron).For an explanation of Luftwaffe unit designations see Organization of the Luftwaffe during World War II.

World War II World War II in Europe began on Friday 1 September 1939 when German forces invaded Poland. At the time, III. Gruppe was under the command of Hauptmann (Captain) Werner Mölders and had just been formed at Wiesbaden-Erbenheim on 26 September 1939. Müller's commanding officer with 8. Staffel was Oberleutnant (First Lieutenant) Hans von Hahn. Müller flew combat missions during the Phoney War period and received the Iron Cross 2nd Class () on 17 April 1940. He claimed his first aerial victory during the Battle of France. On 27 May 1940, during the Dunkirk evacuation, he shot down an Armée de l'Air Curtiss Hawk in the vicinity of Amiens. On 10 June, he was credited with the destruction of three French Morane-Saulnier M.S.406 fighter aircraft. The Geschwader flew its last combat missions in the French Campaign on 19 June. On 20 June, III. Gruppe provided fighter cover in the vicinity of Compiègne during the armistice negotiations which was signed on 22 June.

Müller flew through the Battle of Britain adding two Royal Air Force (RAF) fighters to his eight claims after the Battle of France. On 5 September, he claimed a RAF Supermarine Spitfire during an air-sea rescue mission. On 15 September, Müller ran out of fuel in his Messerschmitt Bf 109 E-4 (Werknummer 5251—factory number), resulting in a forced landing in the English Channel.

Operation Barbarossa In preparation of Operation Barbarossa, the German invasion of the Soviet Union, JG 53 arrived in Mannheim-Sandhofen on 8 June 1941 where the aircraft were given a maintenance overhaul. On 12 June, the Geschwader began its relocation east, with III. Gruppe moving to Suwałki in northeastern Poland. Two days later, III. Gruppe transferred to a forward airfield at Sobolewo. Here, JG 53 was subordinated to Luftflotte 2 (Air Fleet 2) and was deployed on the right flank of Army Group Centre. The Gruppe flew its first combat mission in the early morning hours of 22 June, with 8. Staffel strafing an airfield at Ossów. Müller claimed his first two aerial victories on the Eastern Front that day. On 29 June, he was shot down and wounded near Krespiga in his Bf 109 F-2 (Werknummer 8153) by friendly anti-aircraft fire.

In early October 1941, III. Gruppe was withdrawn from the Eastern Front, the air elements returned to Mannheim-Sandhofen on 4 October while the ground crew followed by train on 13 October. By this date, Müller was credited with twenty aerial victories.

Siege of Malta On 1 November 1941, Müller was transferred to the I. Gruppe of JG 53. Here, he was appointed Staffelkapitän (squadron leader) of 1. Staffel, succeeding Oberleutnant Hans-Joachim Heinecke who was transferred. In December, this unit was moved to Mediterranean air bases at Gela in Sicily. On 20 December, on a Junkers Ju 88 escort mission to La Valletta, Müller claimed a Hawker Hurricane shot down, his 21st aerial victory. In total, he claimed three Hurricanes over Malta. In early May 1942, I. Gruppe handed its aircraft over to those units staying in Sicily and relocated to Schwäbisch Hall. There, the Gruppe was equipped with a full complement of factory new Bf 109 F-4.

Back on the Eastern Front

In support of Case Blue, the 1942 strategic summer offensive in southern Russia, I. Gruppe of JG 53 began its relocation to the Eastern Front on 28 May 1942, arriving at Kursk that evening. Based at Kursk for the next three weeks, I. Gruppe supported the 4th Panzer Army in its drive towards Voronezh. The first combat missions were flown on 31 May in the vicinity northeast of Kursk. Müller claimed his first aerial victory in this theater of operations on 3 June over an I-61, a designation for the Mikoyan-Gurevich MiG-1 fighter aircraft. On 31 July, I. Gruppe was moved to Frolovo to provide air cover for 6th Army drive to Stalingrad. By this date, Müller's number of aerial victory claims had increased to 39.

In August, Müller claimed some 25 victories, and in September claimed a further 35 victories. On 10 September, Leutnant Walter Zellot the commander of 2. Staffel of JG 53 was killed in action. The following day, Müller, in addition to his command of 1. Staffel, was also given command of 2. Staffel. As the standard armament of Bf 109 proved largely ineffective against heavily armored Ilyushin Il-2 ground-attack aircraft, additional firepower was provided through a pair of 20 mm MG 151/20 cannons installed in conformal gun pods under the wings of the Bf 109. I. Gruppe was also provided with a number of these up-gunned Bf 109s. On 18 September 1942, flying a "gunboat" Bf 109, Müller claimed six Il-2 ground-attack aircraft, taking his total to 97 aerial victories. The next day, Müller received the Knight's Cross of the Iron Cross () on 19 September 1942 following a series of 18 enemy aircraft destroyed: five on 16 September, three on 17 September, six on 18 September and three on 19 September. On the latter day, he claimed his 98th and 100th aerial victories. He was the 23rd Luftwaffe pilot to achieve the century mark.

Together with Wilhelm Crinius, Müller received the Knight's Cross of the Iron Cross with Oak Leaves () on 23 September 1942. He was the 126th member of the German armed forces to be so honored. The presentation was made by Adolf Hitler in October at the Führerhauptquartier Werwolf, Hitler's headquarters located in a pine forest about north of Vinnytsia, in Ukraine. Three other Luftwaffe officers were presented with the Oak Leaves that day by Hitler, Oberleutnant Wolfgang Tonne, Leutant Hans Beißwenger and Feldwebel Crinius. Müller was promoted to Hauptmann (captain) on 24 October 1942. Following the presentation, Müller, Tonne and Crinius were ordered to Berlin where they made a propaganda appearance at the "House of the Press". At the same time, I. Gruppe of JG 53 relocated from the Eastern Front to Comiso Airfiled in Sicily where they arrived on 10 October.

North Africa and Sicily

When British forces launched the Second Battle of El Alamein on 23 October, elements of I. Gruppe of JG 53 were ordered to North Africa. In November 1942, Müller was appointed Gruppenkommandeur (group commander) of I. Gruppe of JG 53 and led the unit in Tunisia. On 25 November, I. Gruppe moved from Tunis to Djedeida Airfield. Müller went on leave shortly before Christmas 1942 and returned to his unit at around 23 January 1943. During his absence, command of I. Gruppe temporarily was handed over to Tonne, commander of 3. Staffel. Müller claimed his first aerial victories in this theater of operations on 31 January 1943, shooting down a United States Army Air Forces (USAAF) Boeing B-17 Flying Fortress between Béja and Souk El Khemis. On 25 January, Müller flipped and damaged his aircraft Bf 109 G-6 (Werknummer 14510) during landing at Bizerte Airfield. on 31 January 1943, he claimed his two aerial victories, shooting down a USAAF B-17 bomber and a Lockheed P-38 Lightning fighter aircraft. On 23 March, Müller was engaged with P-38 fighters from the 1st Fighter Group escorting bombers to Bizerte. In this encounter, it is likely that he shot down Lieutenant Slater who baled out off-shore. Two days later, British intelligence believed that Müller had been captured. This assumption was caused by confusing the Staffelkapitän of 1. Staffel, Leutnant Hans Möller who was shot down and captured, with Müller.

On 20 April 1943, Tonne was killed in a flying accident, this event had a significant effect on Müller and influenced his health. On 24 April, Müller claimed two RAF Spitfires shot down, taking his overall score to 114 aerial victories. He claimed his 115th overall and last victory in the North African theater of operations over a Curtiss P-40 Warhawk on 30 April. Following this mission, I. Gruppe handed its aircraft over to II. Gruppe, and the pilots and ground crew were transported by sea to Sicily shortly before the German surrender in North Africa on 12 May.