Production. B-17F heavy bombers. Two soldiers of the production lines at the Long Beach, California, plant of Douglas Aircraft Company. The woman in the foreground works inside of a B-17F heavy bomber nacelle; the woman in the background moves spot-welded wing sheets. Better known as the "Flying Fortress," the B-17F is a later model of the B-17, which distinguished itself in action in the South Pacific, over Germany and elsewhere. It is a long range, high altitude, heavy bomber with a crew of seven to nice men and with armament sufficient to defend itself on daylight missions

The Boeing B-17 Flying Fortress is a four-engine heavy bomber developed in the 1930s for the United States Army Air Corps. Although Boeing lost the contract because the prototype crashed, the air corps was so impressed with Boeing's design that it ordered 13 more B-17s for further evaluation. The B-17 was primarily employed by the United States Army Air Forces in the daylight precision strategic bombing campaign of World War II against Germany. The B-17 also participated to a lesser extent in the War in the Pacific, early in World War II, where it conducted raids against Japan.