The Boeing B-29 Superfortress was an American four-engine heavy bomber, and easily the largest aircraft of World War II. It was the primary US strike weapon against Japan and continued to serve long after the war was over.
Boeing began planning for a very large, long range bomber in 1938, an aircraft far larger and more ambitious than any yet built. It was a very ambitious project - too ambitious, some felt - but it was not the first time Boeing had tried to build a giant bomber. Their B-17 had been an equally ambitious design when it was first planned in 1934, and its development had been long and troubled. Nevertheless, Boeing offered its design study for a still more advanced pressurised development of the B-17 to the United States Army Air Corps in 1938 and, though there was no immediate interest, they were encouraged to keep working on it.
In January 1940, with the B-17 just entering service and the bigger Consolidated B-24 still more than a year away, the Air Corps issued a request for proposals for a much larger bomber, which was to have the range for operation over the Pacific - it being understood that war with Japan was all but inevitable. Four firms submitted design studies, but Douglas and Lockheed soon withdrew. In September 1940 Boeing and Consolidated were awarded development contracts for the XB-29 and the XB-32.
Boeing's extensive design work paid off: even before the prototype had flown for the first time in September 1942, the USAAC had placed a massive order for 1500 B-29s. Within just 12 months, it was in full-scale production.
By the standards of the day, it was an enormous airplane: 30m long, a 43m wingspan, over 32 tonnes empty, and when fully loaded almost 63 tonnes. For range, the mid-set wings had a high aspect ratio, and to keep the landing speed within reason, large Fowler flaps were fitted. Three separate pressurised crew compartments were provided: one in the nose, a second one just aft of the wing for gunners, and a third, isolated one for the tail gunner. Rather than fit traditional bulky manned gun turrets, Boeing used small, remote control units (which were to give endless trouble in the early years).
The manufacturing task was immense, involving four main factories at Renton, Wichita (both Boeing plants), Marietta (Bell) and Omaha (Martin), and thousands of sub-contractors.
The B-29 was used in World War II only in the Pacific and was later used in the Korean War. 3970 of the aircraft were built before they were retired in 1960. B-29s flew 20,000 sorties in Korea and dropped 200,000 tons of bombs.
The B-29 was soon made obsolete by the development of the jet engine and was replaced in the early 1950s by the Convair B-58 "Hustler, the Boeing B-47 "Stratojet, and eventually, the Boeing B-52 "Stratofortress.
As of August, 2003, the only B-29 in the world which is still airworthy is the Confederate Air Force's "Fifi." However, work is actively proceeding at the Boeing plant in Witchita, Kansas on restoring a B-29 named "Doc," and the airplane is expected to fly in 2004. Also, the United States Air Force Museum at the old Wright-Patterson Air Force base is considering restoring "Bock's Car" to airworthy condition; it is presently restored as a static display. In addition, the Smithsonian has not decided whether to restore "Enola Gay" as a static display or to bring the airplane back to flight status.