20FG moved to England in Aug 1943 and became part of 8AF. James M. Morris of 55FS was flying Lockheed P-38H-5-LO Lightning 42-67034 on 15 November 1943 when it suffered damage when landing at Cheddington (Station 113). The aircraft was repaired. 20FG entered combat with P-38's late in Dec 1943 from King’s Cliffe and for several months was engaged primarily in escorting heavy and medium bombers to targets on the Continent. Frequently strafed targets of opportunity while on escort missions. 20FG retained escort duties as its primary function until the end of the war, but in Mar 1944 began to fly fighter-bomber missions, which became almost as frequent as escort operations. They strafed and dive-bombed airfields, trains, vehicles, barges, tugs, bridges, flak positions, gun emplacements, barracks, radio stations, and other targets in France, Belgium, and Germany.
20FG became known as the "Loco Group" because of its numerous and successful attacks on locomotives. It received a DUC for performance on 8 Apr 1944 when the group struck airfields in central Germany and then, after breaking up an attack by enemy interceptors, proceeded to hit railroad equipment, oil facilities, power plants, factories, and other targets. They flew patrols over the Channel during the invasion of Normandy in Jun 1944. Supported the invasion force later that month by escorting bombers that struck interdictory targets in France, Belgium, and Holland, and by attacking troops, transportation targets, and airfields. 42-67034 was transferred to 1FG and was lost in Italy. 20FG converted to P-51's in Jul 1944.