The Schweinfurt–Regensburg mission was a strategic bombing mission during World War II carried out by Boeing B-17 Flying Fortress heavy bombers of the U.S. Army Air Forces on August 17, 1943. The mission was an ambitious plan to cripple the German aircraft industry; it was also known as the "double-strike mission" because it entailed two large forces of bombers attacking separate targets in order to disperse fighter reaction by the Luftwaffe. It was also the first American "shuttle" mission, in which all or part of a mission landed at a different field and later bombed another target before returning to its base.