 Complete the following phrase:  On 16 April 1944 the group moved to RAF Wormingford to accommodate the arrival of the 398th Bomb Group. The 55FG converted to North American P-51D Mustangs in July 1944, continuing their primary task of escorting B-17 and B-24 bombers that attacked such targets as industries and marshalling yards in Germany, and airfields and V-weapon sites in France. In July the group attacked gun emplacements during the Saint-Lô breakthrough in July 1944, and transportation facilities during the 