Humanities › History & Culture World War II: Boeing B-29 Superfortress Share Flipboard Email Print U.S. Air Force History & Culture Military History Aerial Battles & Aircraft Battles & Wars Key Figures Arms & Weapons Naval Battles & Warships Civil War French Revolution Vietnam War World War I World War II American History African American History African History Ancient History and Culture Asian History European History Genealogy Inventions Latin American History Medieval & Renaissance History The 20th Century Women's History View More By Kennedy Hickman Military and Naval History Expert M.A., History, University of Delaware M.S., Information and Library Science, Drexel University B.A., History and Political Science, Pennsylvania State University Kennedy Hickman is a historian, museum director, and curator who specializes in military and naval history. He has appeared on The History Channel as a featured expert. our editorial process Facebook Facebook Kennedy Hickman Updated February 27, 2019 Specifications General Length: 99 ft.Wingspan: 141 ft. 3 in.Height: 29 ft. 7 in.Wing Area: 1,736 sq. ft.Empty Weight: 74,500 lbs.Loaded Weight: 120,000 lbs.Maximum Takeoff Weight: 133,500 lbs.Crew: 11 Performance Maximum Speed: 310 knots (357 mph)Cruising Speed: 190 knots (220 mph)Combat Radius: 3,250 milesRate of Climb: 900 ft./min.Service Ceiling: 33,600 ft.Power Plant: 4 × Wright R-3350-23 turbosupercharged radial engines, 2,200 hp each Armament 12 × .50 cal. M2 Browning machine guns in remote controlled turrets20,000 lbs. of bombs (standard load) Design One of the most advanced bombers of World War II, the design of the Boeing B-29 began in the late 1930s as Boeing began exploring the development of a pressurized long-range bomber. In 1939, General Henry A. "Hap" Arnold of the U.S. Army Air Corps issued a specification for a "superbomber" capable of carrying a payload of 20,000 pounds with a range of 2,667 miles and a top speed of 400 mph. Starting with their earlier work, the design team at Boeing evolved the design into the Model 345. This was submitted in 1940 against entries from Consolidated, Lockheed, and Douglas. Though the Model 345 earned praise and soon became the preferred design, the USAAC requested an increase in defensive armament and the addition of self-sealing fuel tanks. These changes were incorporated and three initial prototypes were requested later in 1940. While Lockheed and Douglas withdrew from the competition, Consolidated advanced their design which would later become the B-32 Dominator. The continued development of the B-32 was seen as a contingency plan by the USAAC in case issues arose with the Boeing design. The following year, the USAAC examined a mock-up of the Boeing aircraft and were sufficiently impressed that they ordered 264 B-29s before ever seeing the aircraft fly. The aircraft first flew on September 21, 1942, and testing continued through next year. Designed as a high-altitude daytime bomber, the aircraft was capable of reaching 40,000 ft., allowing it to fly higher than most Axis fighters. To achieve this while maintaining a suitable environment for the crew, the B-29 was one of the first bombers to feature a fully-pressurized cabin. Utilizing a system developed by Garrett AiResearch, the aircraft had pressurized spaces in the nose/cockpit and the rear sections aft of the bomb bays. These were connected by a tunnel mounted over the bomb bays which allowed the payload to be dropped without having to depressurize the aircraft. Due to the pressurized nature of the crew spaces, the B-29 could not employ the types of defensive turrets used on other bombers. This saw the creation of a system of remote-controlled machine gun turrets. Utilizing the General Electric Central Fire Control system, B-29 gunners operated their turrets from sighting stations around the aircraft. Additionally, the system allowed one gunner to operate multiple turrets simultaneously. Coordination of defensive fire was overseen by the gunner in the forward upper position who was designated as the fire control director. Dubbed the "Superfortress" as a nod to its predecessor the B-17 Flying Fortress, the B-29 was beset with problems throughout its development. The most common of these involved issues with the aircraft's Wright R-3350 engines which had a habit of overheating and causing fires. A variety of solutions were ultimately designed to counter this problem. These included adding cuffs to the propeller blades to direct more air into engines, increased oil flow to the valves, and frequent replacement of cylinders. Production A highly sophisticated aircraft, problems persisted even after the B-29 entered production. Built at Boeing plants in Renton, WA, and Wichita, KS, contracts were also given to Bell and Martin who built the aircraft at plants in Marietta, GA, and Omaha, NE respectively. Changes to the design occurred so frequently in 1944, that special modification plants were built to alter the aircraft as they came off the assembly line. Many of the problems were the result of rushing the aircraft in order to get it into combat as quickly as possible. Operational History The first B-29s arrived at Allied airfields in India and China in April 1944. Originally, the XX Bomber Command was to operate two wings of B-29s from China, however, this number was reduced to one due to a lack of aircraft. Flying from India, B-29s first saw combat on June 5, 1944, when 98 planes struck Bangkok. A month later, B-29s flying from Chengdu, China struck Yawata, Japan in the first raid on the Japanese home islands since the Doolittle Raid in 1942. While the aircraft was able to attack Japan, operating the bases in China proved costly as all supplies needed to be flown in over the Himalayas. The problems of operating from China were averted in the fall of 1944, following the US capture of the Marianas Islands. Soon five major airfields were constructed on Saipan, Tinian, and Guam to support B-29 raids on Japan. Flying from the Marianas, B-29s struck every major city in Japan with increasing frequency. In addition to destroying industrial targets and firebombing, B-29s mined harbors and sea lanes damaging Japan's ability to resupply its troops. Though meant to be a daytime, high-altitude precision bomber, the B-29 frequently flew at night on carpet-bombing incendiary raids. In August 1945, the B-29 flew its two most famous missions. Departing Tinian on August 6, the B-29 Enola Gay, Colonel Paul W. Tibbets commanding, dropped the first atomic bomb on Hiroshima. Three days later the B-29 Bockscar dropped the second bomb on Nagasaki. Following the war, the B-29 was retained by the US Air Force and later saw combat during the Korean War. Flying primarily at night to avoid Communist jets, the B-29 was used in an interdictive role. Evolution Following World War II, the USAF embarked on a modernization program to enhance the B-29 and correct many of the problems that had plagued the aircraft. The "improved" B-29 was designated the B-50 and entered service in 1947. That same year, a Soviet version of the aircraft, the Tu-4, began production. Based on reverse-engineered American aircraft downed during the war, it stayed in use until the 1960s. In 1955, the B-29/50 was withdrawn from service as an atomic bomber. It continued in use until the mid-1960s as an experimental testbed aircraft as well as an aerial tanker. All told, 3,900 B-29s were built. Sources “Boeing B-29 Superfortress.” National Museum of the USAF, 14 Apr. 2015, www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/196252/boeing-b-29-superfortress/.“B-29 Superfortress Then and Now.” Jason Cohn's Research Paper, b-29.orgAngelucci, Enzo, Rand McNally Encyclopedia of Military Aircraft: 1914-1980 (The Military Press: New York, 1983), 273, 295-296.