Woman at work on motor, Douglas Aircraft Company, Long Beach, Calif.
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.