The B-17 Flying Fortress is the best-known American bomber of World War II. Heavy losses in 1943 when a total of 120 bombers was shot down lead to the conclusion that previous B-17 versions carried insufficient defensive armament. As a consequence the front lower nose of the B-17G was equipped with a turret carrying two 127 mm machine guns providing an effective defense against the feared frontal attacks. Simultaneously supplementary gun positions were added to the fuselage sides. The crew now being able to defend itself in all directions resulted in a sense of safety which was also reflected in its nickname Flying Fortress.