The Boeing B-29 Superfortress was a long-range, heavy bomber used by the US Army's Air Forces during World War II. It became the 'big stick' of the final campaign in that armed conflict. This feared aircraft brought war home to Japan's cities and people, ushering in the atomic age. The B-29 was also used used during the Korean War and it would be converted into a transport and tanker aircraft during the post-war years. It was the first and only aircraft to drop nuclear bombs in anger, flying the two missions that attacked Hiroshima and Nagasaki on August 6 and 9, 1945, respectively. It was also the first pressurized aircraft to be introduced into service. Although it began to fly combat sorties late in the war, it had a strong influence on the outcome of the armed struggle as it was armed with the weapons that put an end to it. During the Cold War, it would be developed into the Boeing B-50, also a long-range bomber.
The design of the B-29 Superfortress started in 1940 to meet the US Army's Air Corps requirement for a 'hemisphere defense weapon'. On September 6 that year, Boeing was awarded the $ 3,615,095 contract for building two XB-29 prototypes; three months later a third prototype would be added. The first of them made its maiden flight on September 21, 1942. Almost two years of flight tests had gone by when the aircraft was finally accepted, entering service with the US Army's Air Forces on May 8, 1944. This new heavy bomber flew its first combat sortie on June 5, 1944, taking off from airbases in India to attack Japanese military depots and command centers in Bangkok, Thailand. After the Battle of Iwo Jima, the B-29 began taking off from the new Allied airbase on this island to carry out bombing raids over Japanese cities. The most famous missions conducted by this heavy bomber were the ones in which it dropped two atomic bombs on Hiroshima and Nagasaki. A total of 3,970 bombers were made in different versions.
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| Above, the B-29D version in flight over China in early 1945. |
Technical Description
The Boeing B-29 Superfortress was a large, four-engine monoplane of all-metal construction. It was fitted with wide-span mid-wing. The basic airframe was made of aluminum alloy, with a semi-monocoque fuselage and stringers arrangement which had been used for the construction of the B-17 Flying Fortress. The fuselage had a circular cross-section, whose purpose was twofold: to obtain maximum strength for pressurization and for a streamline shape and flight efficiency. It was built in four separate sections, which were assembled on the production line. Two aluminum web spars were employed to build the wing, which was made stable through the use of a 4.5-degree dihedral angle and a 7-degree leading edge sweepback. The ailerons and flaps occupied the full length of the trailing edge.
The tail assembly, or empennage, consisted of cantilever vertical and horizontal stabilizers (fin and tailplane). These were built with spars and ribs covered with stressed sheet metal skins. Fabric was used on the elevators and rudder. All the primary flight controls, such as ailerons, rudder, and elevators, were cable-operated. Electricity was supplied by a 28-volt direct current, which was produced by six generators powered by the engines. The tricycle landing gear of the B-29 was entirely conventional, except for size, and it was electrically operated. The first version of the aircraft, the B-29A, was powered by four Wright Cyclone R-3350-5, 18-cylinder, piston engines, each of them producing 2,200 horsepower. For its bombing missions and navigation, the aircraft was equipped with an AN/APQ-7 radar.
Specifications
Type: long-range heavy bomber
Length: 30.18 m (99 feet, 2 inches)
Wing Span: 43.05 m (141 feet, 3 inches)
Wing Area: 161.27 m2 (1,736 square feet)
Height: 9 m (29 feet, 7 inches)
Power Plant: four 2,200-HP, Wright R-3350-5, Duplex-Cyclone, 18-cylinder, turbo-charged piston engines.
Maximum Speed:576 km/h (358 mph)
Range: 5230 km (3,250 miles)
Service Ceiling: 9,170 m (30,095 feet)
Crew: 11
Armament: eight 12.7-mm (.50-cal) machine guns mounted in four remotely control turrets; one 20-mm gun in tail (sometimes a pair of .50-cal machine guns); 9,072 kg (20,000-lb) of bombs in bomb-bay.
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| The B-29A flying over California in May, 1944. |
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| B-29s from 500th Bomb Group in the skies over Japan dropping incendiary bombs. |
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| The Superfortress bombers in flight around July 1945, with olive-green camouflage. |
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| Front view of the B-29. The 4.5-degree dihedral angle of wing is clearly noted. |
