The group assembled at its combat station, RAF Glatton by the end of the month. The air echelon had begun arriving at Glatton on 21 January. The group flew its first mission during Big Week on 21 February 1944, as Eighth Air Force concentrated its attacks on Germany's aircraft manufacturing industry. It engaged primarily in the strategic bombing campaign against Germany, attacking ball bearing plants, oil refineries and aircraft factories until June 1944. In July 1944, the group returned to strategic targets, which remained its primary objectives through April 1945. On 2 November 1944, the 457th and another group strayed from the main bomber stream and its fighter cover. Luftwaffe fighter controllers directed a geschwader of interceptors against the formation. Nine of the 457th Group's Flying Fortresses were lost to this attack.