The B-17D Flying Fortress, known as The Swoose, is the oldest surviving B-17 and the only D-model in existence, at the National Museum of the U.S. Air Force, Wright-Patterson Air Force Base, Ohio. The aircraft flew combat missions in the opening days of World War II before later serving as a transport aircraft and is now undergoing a long-term restoration and conservation effort. (U.S. Air Force photo by Ken LaRock)