 It participated in the assault against the German Air Force and aircraft industry during Big Week, 20–25 February 1944; the Normandy invasion, June 1944 and the Saint-Lô breakthrough in July.The weight of the heavy P-47 fighters soon began to tell on the wet surface making take-offs tricky.A team of American engineers were called in during January 1944 and, in three days, they constructed a 1,470-yard-long runway with pierced-steel planking.