 DATE: In the beginning when they are leaving, they pass a sign that  shows the joint forces for both the U.S. and the British. It shows  that it is the U.S.A.F (United States Air Force) when, during World  War II, it would have been U.S.A.A.C (United States Army Air Corp),  or even U.S.A.A.F (United States Army Air Force)