Superfortress Summary

  • Last updated on November 10, 2022

A very-long-range (VLR), four-engine U.S. bomber of the World War II era.

Development and Production

Measuring 99 feet in length and 142 feet in wingspan, weighing 120,000 pounds loaded, and costing $930,000 per aircraft, the B-29 was the largest and most expensive bomber from World War II. Size and cost, however, were only two of the attributes that set the Superfortress apart from other propeller bombers of the era. The B-29 flew higher (31,800 feet) and faster (365 miles per hour), carried a heavier bomb load (10 tons maximum), mounted greater armament (ten .50-caliber machine guns and one 20-millimeter cannon), and had a longer range (4,100 miles) than any other World War II bomber.

Additionally, its engines (four 2,200 horsepower Wright R-3350’s), radar (APQ-13), pressurized cabins, remote-controlled armament, and use of a flight engineer marked the Superfortress as a new generation of bomber.

The Boeing Company, developer and manufacturer of the B-17 Flying Fortress, designed the B-29 in response to the desire of the U.S. Army Air Corps (renamed the U.S. Army Air Force in 1941) for a bomber superior in speed, bomb load, and range to those it already possessed, specifically the B-17 and B-24. After working up several models during 1939, Boeing engineers finally submitted a design in the spring of 1940, which was designated the XB-29. This design came close to meeting Air Corps’ specifications, which included a top speed of 400 miles per hour, a bomb load of 1 ton, and a range of 5,333 miles. Awarded a contract to deliver three XB-29’s, Boeing proceeded to create and test the plane that would become the Superfortress.

During testing, numerous problems cropped up, including a three-bladed propeller that proved deficient at high altitudes, hydraulic brakes that failed at landing, a multiwindowed cockpit that produced distorted visibility, gunners’ sighting blisters whose windows frosted over, and a fire-control system that lacked accuracy. None of these problems, however, was as serious as the tendency of the Wright R-3350 engines to overheat and catch fire at high revolutions per minute. In fact, engine problems delayed the initial test flight, originally scheduled for July, 1942, until September of that year. They also led to the tragic death of Boeing’s chief test pilot, Eddie Allen, who was killed along with his entire ten-man crew when the Superfort they were testing crashed in Seattle on February 18, 1943, and forced some two thousand changes by November, 1943.

Despite the plane’s many bugs, some of which were never completely overcome, General Henry Harley “Hap” Arnold and other U.S. Army Air Force leaders remained committed to the B-29. Consequently, in 1943, they contracted with Boeing, Bell, and Martin to manufacture Superfortresses. Together, these three companies combined to produce 3,432 Superfortresses by war’s end in August, 1945.

World War II

The B-29 became operational in June, 1944, when Superfortresses of Twentieth Bomber Command, U.S. Fourteenth Air Force began flying from Chinese bases, bombing targets in Thailand and in Japan’s home islands. Five months later, in November, B-29’s of Twenty-first Bomber Command, U.S. Twentieth Air Force, headquartered in the recently captured Mariana Islands, commenced bombing raids against the home islands. Because of the logistical difficulties involved in supplying the Superfortresses deployed in China and the great distance between the Chinese bases and their targets in Japan, the Marianas served as the main base of operations for the B-29 strategic air offensive from late 1944 until war’s end.

During fourteen months of active service in World War II, B-29’s dropped 170,000 tons of bombs, 146,000 on Japan itself, and laid 147,000 tons of aerial mines in Japanese and Korean waters. As a strategic bomber, the Superfortress proved most effective from early March to mid-August, 1945, when, thanks to General Curtis E. LeMay, commander of Twenty-first Bomber Command, Twentieth Air Force abandoned high-altitude, daylight, precision raids using high explosive bombs in favor of low-altitude, nighttime, area raids using incendiary bombs. In this period, B-29 raids burned down 40 percent of urban Japan, inflicted an estimated 830,000 casualties (500,000 killed), destroyed 2.5 million buildings, reduced Japanese oil production by 80 percent, reduced its aircraft production by 75 percent, and reduced the number of its munitions factories in operation by 30 percent. The B-29 air offensive against Japan reached a destructive climax with its employment as the world’s first nuclear bomber, when the Enola Gay dropped the uranium-based “Little Boy” atomic bomb on Hiroshima (August 6, 1945) and the Bock’s Car dropped the plutonium-based “Fat Man” atomic bomb on Nagasaki (August 9, 1945).

Post-World War II Usage

After World War II, the development of jet-powered aircraft ultimately made the B-29 obsolete. However, the U.S. Army Air Force—and, from 1947, the U.S. Air Force—included Superfortresses in all bomber units until 1954. Superfortresses were employed as nuclear bombers until 1951 and saw action as conventional bombers in the Korean War (1950-1953), dropping an estimated 158,000 tons of bombs during that conflict. Great Britain briefly incorporated B-29’s into the Royal Air Force in the early 1950’s, while the Soviet Union, in the late 1940’s, mass-produced a version of the Superfortress, designated the Tu-4, which the air force copied from U.S. Superfortresses that had made emergency landings in Siberia during World War II.

Although enjoying a relatively brief lifetime as a combat aircraft and plagued by numerous technological problems throughout, the B-29 Superfortress is generally acknowledged as the best bomber of World War II.

  • Pimlott, John. B-29 Superfortress. Englewood Cliffs, N.J.: Prentice Hall, 1993. Offers detailed information about the Superfortress and includes excellent illustrations.
  • Vander Meulen, Jacob. Building the B-29. Washington, D.C.: Smithsonian Institution Press, 1995. Details Boeing’s construction of the Superfortress.
  • Werrell, Kenneth P. Blankets of Fire. Washington, D.C.: Smithsonian Institution Press, 1996. An excellent history of the U.S. strategic bombing campaign against Japan. Includes much information about the design and development of the B-29.

Air Force, U.S.



Korean War

Military flight

Royal Air Force

World War II

The B-29’s long range gave it an advantage in the Pacific theater ofWorldWar II; the Enola Gay, the plane that dropped the atomic bomb on Hiroshima, Japan, was a B-29.

(Library of Congress)
Categories: History