Production. B-17F heavy bombers. Even the icebox had its place in the modern aircraft assembly line. Certain types of rivets fit more perfectly when they are installed in the cold or shrunken state. The girl is removing a supply of rivets from dry ice in the Long Beach, California, plant of Douglas Aircraft Company. Better known as the "Flying Fortress," the B-17F is a later model 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