Staff Writer (Updated: 4/25/2016):
The B-29, like the Boeing B-17 Flying Fortress before it, was developed to a US Army Air Corps requirement for a high-level heavy bomber capable of extended operational ranges and increased payloads while operating at speeds nearing 400 miles per hour. The range requirement was of particular note for the vast distances of the Pacific required a long-range thoroughbred. The B-29 program began at a slow pace prior to America's entry into World War 2. After the Japanese attack on Pearl Harbor, the B-29 program was pushed into full gear. The first of three XB-29 prototypes took to the air in 1942 with government orders already secured for over 1,500 production units.
The B-29 Superfortress was a mid-wing monoplane design centered on a tubular fuselage powered by four large radial piston engines. The pencil-like fuselage was heavily-glazed at the nose and provided the identifiable appearance for the series. Crew accommodations included ten personnel made up of pilots, bombardiers, navigators, specialists and gunners. All weapon systems were held in electrically-powered turret "barbettes" operated by way of integrated periscopes and fitted in dorsal, ventral and tail gun positions. At any rate, this armament arrangement represented a vast departure from any bomber defenses fielded during the war, essentially necessitated by the B-29's high operating altitude (the B-17 still utilized open air machine gun ports, exposing the crew to the bitter cold temperatures of high-level flight). Several modified - or converted - models of the B-29 were used exclusively for crew training, as dedicated Search and Rescue (SAR) systems, dedicated reconnaissance platforms outfitted with camera and weather survey platforms before the end of the aircraft's production run. By the time of the Korean War, daylight bombing runs had become becoming increasingly costly to B-29 crews thanks to the arrival of the Soviet-built, single-seat, jet-powered Mikoyan-Gurevich MiG-15 "Fagot" fighters. As such, night time bombing campaigns grew in number as the B-29 continued serving under the new USAF Strategic Air Command (SAC).
The B-29 fitted a bevy of 12.7mm Browning M2 heavy machine guns. Four were installed in an electrically-operated dorsal turret while a second dorsal turret fitted two more. A pair of 12.7mm machine guns were installed in a chin position with another two-gun system under the rear fuselage. A pair of machine guns was installed in the tail to counter any trailing enemy aircraft attempting to make the interception. Beyond her machine gun armament, the B-29's true value came in her ability to carry up to 20,000lbs of internal ordnance.