The XB-29 had wings that were as small as possible, with large radial engines outside them. While crew space fore and aft had to be pressurized, the bomb bays (with their huge doors) could not be. To deal with this problem, Boeing linked the front and rear pressurized sections with a sealed tunnel. Problems like preventing guns and propeller mechanisms from freezing at high altitudes abounded.

At altitudes of 30,000 feet, manned gun turrets were impractical and Sperry developed retractable, periscopically directed, electrically powered turrets for the B-29. The normal crew of twelve included a pilot, co-pilot, bombardier, navigator, flight engineer, radio operator, radar operator, and five gunners. The first seven guys occupied the forward pressurized cabin. Four gunners were in the rear cabin, and the poor tail gunner was trapped in his own little pressurized pocket in the tail for the duration of the flight.

By mid-1943, the Wichita plant started to deliver the fourteen YB-29 service test aircraft to the 58th Bomb Wing. In the YB-29's, Sperry's turrets were replaced by non-retractable GE types, operated with computerized gunsights. The GE turrets could be operated with one less gunner, but their demands for electrical power increased the weight of the aircraft to 105,000 pounds.

Powered by four 2200 hp Wright R-3350-23 radial engines driving 16-foot, 7-inch four-bladed propellers, the B-29 could cruise at 342 MPH at 30,000 feet. Over long distances, its economical cruising speed was 220 MPH at 25,000 feet. A few early B-29's were camouflage painted; the rest were left in natural metal finish. Thirty fuel tanks (in the wings and the bomb bay) carried over 9400 gallons of gasoline. Radar-assisted navigation and bombing sets helped the Superforts get to their targets and drop their bombs accurately.

Like most other bombers, the B-29's development was marked by an increase in defensive firepower, particularly from frontal attacks. In the B-29's case, the forward dorsal turret machine guns were increased from two to four. However, in the tail, the original 20mm cannon was removed, because its shells' trajectory was so different from the 50 caliber machine guns' that it made aiming difficult.

The Manhattan Project, in highest secrecy during 1943 and 1944, built two such bombs, a plutonium bomb dubbed "Fat Man," and a uranium bomb, "Little Boy." The 509th Composite Group was charged with delivering the new bombs, in specially modified B-29's, each capable of carrying and releasing a 10,000 pound atomic bomb. Commanded by Colonel Paul W. Tibbets, Jr., the men of the 509th knew nothing of their proposed mission.  On August 6, 1945, the Enola Gay dropped "Little Boy" on Hiroshima. 75,000 people died and almost 50,000 buildings were destroyed. 

The Allies had expected, or perhaps hoped, that Japan would surrender after suffering the effects of an atomic bomb. But the Japanese government could not commit itself to surrender so quickly. In part they did not understand what had happened; in Tokyo all that was immediately certain was that all communications with Hiroshima had stopped. While the Japanese cabinet debated, conventional B-29 raids continued, in ever increasing force. Three days later, with no response from the Japanese, "Fat Man" was dropped on Nagasaki. But it worked. That day the Soviets declared war on Japan and invaded Manchuria. The Emperor ordered the government to surrender. He broadcast word of the surrender to the Japanese people on August 15, and it was signed on the decks of the USS Missouri on September 2, 1945.

The B-29's last missions of the war consisted of food drops to POW camps.

B-29 gunners were credited with downing 27 MiGs, making the aircraft the second-highest scoring aircraft, after the F-86 Sabre. One B-29, Command Decision, shot down five MiGs, making the aircraft an ace of sorts.

Relatively few B-29's survive today, in part because (unlike the B-17) they were not declared war surplus after WWII.

Serial number - comment
42-6376 - to storage at Davis-Monthan 6/27/49
42-65281, Miss America '62 - at Travis AFB Museum, CA
42-27297, Bock's Car - the Nagasaki bomber, now on display at WPAFB Museum, OH
44-27343 - at Tinker AFB Air Park, OK
44-61975 - at New England Air Museum
44-69729 - on display at Seattle Museum of Flight, WA
44-69972 - stored on range at Naval Air Warfare Center, China Lake, CA, moved to United States Air Museum, Inyokern, CA and is under restoration
44-70016 - at Pima Air Museum, Tucson, AZ
44-70064 - on display at Castle AFB Museum, plane is actually made up of three derelict targets from China Lake
44-84076 - on display at SAC Museum, Offutt AFB, NE
44-86292, Enola Gay - dropped atomic bomb on Hiroshima
44-86408 - used to collect radioactive samples during postwar atomic tests, now on display at Hill AFB Museum
44-87779 - at South Dakota Air and Space Museum, Ellsworth AFB
45-21763, Kee Bird - abandoned after landing frozen lake in Greenland, during to recover, caught fire and burned May 21, 1995. Check out PBS Nova episode about the efforts to recover Kee Bird.
45-21787, Fertile Myrtle - used as carrier aircraft for D-558-II, registered as NACA 137, now with Weeks Air Museum, Miami, FL
45-21800 - used as "mothership" for X-1 trials
45-21801 - used by NACA between 1945 and 1955