Jagdgeschwader 52 (JG 52) was a German World War II fighter Geschwader (wing) that exclusively used the Messerschmitt Bf 109 throughout the war. The unit originally formed near Munich in November 1938, then moved to a base near Stuttgart. JG 52 became the most successful fighter-Geschwader of the war, with a claimed total of more than 10,000 victories over enemy aircraft during World War II. It was the unit of the top three scoring flying aces of all time, Erich Hartmann, Gerhard Barkhorn and Günther Rall.
In 1935, the Ministry of Aviation designed an air force (Luftwaffe) of 2,370 active planes by April 1938, which would require the production of about 18,000 planes to cover attrition. When 1938 came, the Luftwaffe split its fighter groups into light "Jagdgeschwader" flying the Messerschmitt Bf 109, for home defense, and heavy fighter wings called Zerstörergeschwader flying the Messerschmitt Bf 110, for offensive operations, based on doctrine devised over the 1930s. Although the Luftwaffe simply could not meet its mandated pre-Munich Agreement size, five times its then current size, aircraft poured into the various Geschwader around the country.
At the Ingolstadt-Manching base, north of Munich, I./JG 433 was activated as the first Gruppe of Luftflotte 3 under the command of Hauptmann Dietrich Graf von Pfeil und Klein-Ellguth, who had commanded a provisional air unit during the Sudeten crisis. After the Munich Agreement, aircraft flooded into JG 433 in spite of the unit not even having a dozen pilots. By December, it had an almost full complement of Bf 109Ds, but a severe freeze around Christmas 1938 rendered them all inoperable. Improving weather and incoming trainees in the first weeks of 1939 improved JG 433's situation. To train the new pilots was the task of Klein-Ellguth's Staffelkäpitane, Oberleutnants Wolfgang Ewald, Adolf Galland, and Alfons Klein. All three had been members of the Condor Legion during the Spanish Civil War. Klein was killed in a crash on 18 February 1939 and was replaced by Oberleutant Helmut Kühle, also a Condor Legion veteran, on 1 March 1939.