Production. B-17F heavy bombers. The upper power turret of a new B-17F heavy bomber, just produced at the Long Beach, California, plant of Douglas Aircraft. Turrets like this have meant the finish of many Jap and Nazi flyers. 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