In early 1944, the Allied air war began to focus primarily upon the destruction of the Luftwaffe in preparation for the invasion of Normandy. Plans for the so-called "Big Week", which was intended to permanently smash the German capacity to produce fighter aircraft through targeted airstrikes on final assembly factories, were already underway in 1943. Between February 20–25, 1944, approximately 10,000 American and British aircraft, including about 6,000 bombers, attacked strategic targets all over Germany.