A girl riveting machine operator at the Douglas Aircraft Company plant joins sections of wing ribs to reinforce the inner wing assemblies of B-17F heavy bombers, Long Beach, Calif. Better known as the "Flying Fortress," the B-17F bomber 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 nine men -- and with armament sufficient to defend itself on daylight missions