Boeing submitted the proposal for the B-29 long-range heavy bomber to the Army in 1940, before the United States entered World War II.
One of the most technologically advanced airplanes of World War II, the B-29 had many new features, including guns that could be fired by remote control. Two crew areas, fore, and aft were pressurized and connected by a long tube over the bomb bays, allowing crew members to crawl between them. The tail gunner had a separate pressurized area that could only be entered or left at altitudes that did not require pressurization.
The B-29 was also the world’s heaviest production plane because of increases in range, bomb load, and defensive requirements.
The B-29 used the high-speed Boeing 117 airfoil, and its larger Fowler flaps were added to the wing area as they increased lift. Modifications led to the B-29D, upgraded to the B-50, and the RB-29 photoreconnaissance aircraft. The Soviet-built copy of the B-29 was called the Tupolev Tu-4.
The earliest B-29s were built before testing was finished, so the Army established modification centers where last-minute changes could be made without slowing expanding assembly lines.
Boeing built a total of 2,766 B-29s at plants in Wichita, Kan., (previously the Stearman Aircraft Co., merged with Boeing in 1934) and in Renton, Wash. The Bell Aircraft Co. built 668 of the giant bombers in Georgia, and the Glenn L. Martin Co. built 536 in Nebraska. Production ended in 1946.
B-29s were primarily used in the Pacific theater during World War II. As many as 1,000 Superfortresses at a time bombed Tokyo, destroying large parts of the city. Finally, on Aug. 6, 1945, the B-29 Enola Gay dropped the world's first atomic bomb on Hiroshima, Japan. Three days later a second B-29, Bockscar, dropped another atomic bomb on Nagasaki. Shortly thereafter, Japan surrendered.
After the war, B-29s were adapted for several functions, including in-flight refueling, antisubmarine patrol, weather reconnaissance, and rescue duty. The B-29 saw military service again in Korea between 1950 and 1953, battling new adversaries: jet fighters and electronic weapons. The last B-29 in squadron use retired from service in September 1960.
| First flight | Sept. 21, 1942 |
| Model number | 345 |
| Classification | Bomber |
| Span | 141 feet 3 inches |
| Length | 99 feet |
| Gross weight | 105,000 pounds (140,000 pounds postwar) |
| Top speed | 365 mph |
| Cruising speed | 220 mph |
| Range | 5,830 miles |
| Ceiling | 31,850 feet |
| Power | Four 2,200-horsepower Wright Duplex Cyclone engines |
| Accommodation | 10 crew |
| Armament | 12 .50-caliber machine guns, 1 20 mm cannon, 20,000-pound bomb load |
Source: https://www.boeing.com/history/products/b-29-superfortress.page
