The 339th Fighter Group was a unit of the United States Air Forces during World War II. It comprised the 503rd, 504th, and 505th Fighter Squadrons. The group was an Eighth Air Force fighter unit stationed in England assigned to RAF Fowlmere. It had the highest claims of air and ground enemy aircraft victories in one year, and was the only group to claim over a hundred ground strafing victories on two occasions – 105 on 4 April 1945 and 118 on 16 April 1945. It was inactivated on 18 October 1945.
The group was reassigned to the 66th Fighter Wing of VIII Fighter Command and stationed at RAF Fowlmere in England in April 1944 and was redesignated 339th Fighter Group in May 1944. They were equipped with P-51 Mustang aircraft and the first combat operation was on 30 April 1944. The unit engaged primarily in B-17/B-24 escort duties during its first five weeks of operations, and afterwards flew many escort missions to cover the operations of medium and heavy bombers that struck strategic objectives, interdicted the enemy's communications, or supported operations on the ground. The group strafed airfields and other targets of opportunity while on escort missions. The 339th received a Distinguished Unit Citation for operations on 10 and 11 September 1944. On the first of those days, when it escorted bombers to a target in Germany and then attacked an aerodrome near Erding, the group destroyed or damaged many enemy planes despite the intense fire it encountered from anti-aircraft guns and small arms. The following day the bomber formation being escorted to Munich was attacked by enemy fighters, but members of the 339th group destroyed a number of the interceptors and drove off the others and at the same time, other members of the 339th were attacking an airfield near Karlsruhe, where they encountered heavy fire but were able to destroy or damage many of the aircraft parked on the field. The 339th provided fighter cover over the English Channel and the coast of Normandy during the invasion of France in June 1944. They strafed and dive-bombed vehicles, locomotives, marshalling yards, anti-aircraft batteries, and troops while Allied forces fought to break out of the beachhead in France. The group attacked transportation targets as Allied armies drove across France after the breakthrough at Saint-Lô in July and flew area patrols during the airborne attack on Holland in September. They escorted bombers and flew patrols during the Battle of the Bulge from December 1944 – January 1945. They provided area patrols during the assault across the Rhine in March 1945.
