A North American B-25 Mitchell medium bomber banks over the hills of Southern California during a factory test flight. Introduced in 1941, the B-25 became one of the most versatile American bombers of World War II, famously used in the 1942 Doolittle Raid on Japan. The plain white star insignia, without the red bars added in mid-1943, helps date this photograph to the early war years. Project: 218474