" In early 1944, General James Doolittle told the fighters to stop flying in formation with the bombers and instead attack the Luftwaffe wherever it could be found. The Mustang groups were sent in before the bombers and could hunt the German fighters while they were forming up. The results were astonishing; in a short period of just over a week, the Luftwaffe lost 17% of its fighter pilots.[19] As Doolittle later noted, "Adolf Galland said that the day we took our fighters off the bombers and put them against the German fighters, that is, went from defensive to offensive, Germany lost the air war."[20]
The Luftwaffe answer was the Gefechtsverband (battle formation). It consisted of a Sturmgruppe of heavily armed and armored Fw 190s escorted by two Begleitgruppen of light fighters, often Bf 109Gs, whose task was to keep the Mustangs away from the Fw 190s attacking the bombers. This scheme was excellent in theory but difficult to apply in practice. The large German formation took a long time to assemble and was difficult to maneuver. It was often intercepted by the escorting P-51s and broken before reaching the bombers; when the Sturmgruppe worked, the effects were devastating. With their engines and cockpits heavily armored, the Fw 190s attacked from astern and gun camera films show that these attacks were often pressed to within 100 yds.[21]
While not always successful in avoiding contact with the escorts, the threat of mass attacks and later the "company front" (eight abreast) assaults by armored Sturmgruppe Fw 190s, brought an urgency to attacking the Luftwaffe wherever it could be found. Beginning in late February 1944, 8th Air Force fighter units began systematic strafing attacks on German airfields with increasing frequency and intensity throughout the spring, with the objective of gaining air supremacy over the Normandy battlefield. In general, these were conducted by units returning from escort missions but beginning in March, many groups also were assigned airfield attacks instead of bomber support. The P-51, particularly with the advent of the K-14 Gyro gunsight and the development of "Clobber Colleges" for the training of fighter pilots in fall 1944, was a decisive element in Allied countermeasures against the Jagdverbände.
The numerical superiority of the USAAF fighters, superb flying characteristics of the P-51 and pilot proficiency helped cripple the Luftwaffe's fighter force. As a result, the fighter threat to US and later British bombers, was greatly diminished by July 1944. Reichmarshal Hermann Göring, commander of the German Luftwaffe during the war was quoted as saying, "When I saw Mustangs over Berlin, I knew the jig was up."[22][23] "
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