B-17G Flying Fortress
Developed in the 1930s for the United States Army Air Corps, the four-engine B-17 Flying Fortress heavy bomber was often equipped with up to 13 .50-caliber machine guns at once. Distinguishing features of the "G" variant - the final version - included a Bendix remotely-operated chin turret and revised, remotely-operated tail gun turrets. An estimated 8,680 "G" aircraft were produced and many were converted for other uses, including troop transports and recon aircraft.