Although the design was already in the works before Pearl Harbor, the B-29 was one of the most technologically advanced aircraft to be produced during the war.
“Icons of Aviation History” is a diary series that explores significant and historic aircraft.
In 1940, things were looking bleak for the United States. England had barely survived the Battle of Britain and was being pounded by the Blitz, and soon Hitler’s troops would be driving deep into Russia. It looked increasingly possible that the United States might be the only remaining democracy, and with the loss of France, Britain and Russia as allies, the US may have been forced to wage a long-distance war. The Army Air Force had just deployed the new B-17 Flying Fortress and B-24 Liberator heavy bombers, but neither of these had anything near the capability to strike across the vast expanses of the oceans.
In response the United States considered two new strategic bomber designs. The four-engined Consolidated B-32 concept offered gains in speed, range and payload over the B-17 and B-24, and featured a pressurized crew compartment. But the B-29 proposal by Boeing was a radical leap forward: it too had pressurized crew compartments, but also promised remote-controlled guns operated by analogue computers, and a radar-guided bomb-aiming system that gave all-weather accuracy.
In April 1941, the Army placed an order for 250 B-29s before the prototype had even been built (this was soon increased to 1,500). And, as an insurance policy in case the Boeing ran into difficulties and didn’t work as advertised, the Air Corps also placed an order for Consolidated’s B-32, which became known as the “Dominator”. Around 100 were built, but only 15 ever entered service.
After the attack on Pearl Harbor near the end of 1941, Japanese forces quickly overran much of southeast Asia, and now the US needed a heavy strategic bomber which could handle the extreme long ranges in the Pacific, and needed it quickly. The B-29 “Superfortress”, with a speed of 359mph and a range over 4,000 miles, fit the bill. The first B-29 prototype flew in September 1942.
The Superfort could deliver 10,000 pounds of bombs: these were carried in two bomb bays fore and aft of the center of gravity, and the bombs were released alternately from each bay. There were ten .50-caliber machine guns in five turrets, which were operated remotely by gunners inside the pressurized crew compartments. Each gunner could control several turrets at once to concentrate his fire. The tail turret also carried a 20mm cannon.
The plane had a crew of ten. In the Plexiglas nose sat the bombardier, who used the AN/APQ-7 Eagle radar set to find his target even under cloud cover. Above him in the cockpit were the pilot and co-pilot, behind them were the navigator and flight engineer, and the radio operator sat further aft. In the tail compartment, connected to the crew compartment by a pressurized tunnel, was the turret gunner, two side gunners, and the tail gunner.
Even as the prototypes were undergoing flight testing, the companies who would manufacture the new plane—Boeing, Bell, and Martin—were constructing huge new factories for the assembly lines. Curtiss-Wright and Dodge Auto Company, meanwhile, had already begun making 2200-horsepower Wright R-3350 Duplex Cyclone turbo-supercharged radial engines for the big bombers. They were the most powerful piston engines produced during the war.
Even as assembly lines went into action, constant new changes and modifications were being made to the design. Smaller satellite factories were set up where updates could be made to planes after they had left the main factory, so as not to interfere with production.
By 1943, the war in the Pacific had been turned around, and the War Department made plans to begin bombing the cities of Japan with B-29 bombers based in China. But there were difficulties with the B-29 assembly lines, and production at first was slow. Then, Chinese forces under Chiang Kai-shek proved unable to deal with the Japanese, and when the planned locations for the bomber bases were overrun by a Japanese offensive, it appeared that, with China unavailable, the US would need to bomb Japanese cities from bases in the Pacific Islands.
The first operational B-29 squadrons were in place in Calcutta, India, by May 1944. They were too far away to hit Japan, but they were able to bomb targets in China and Burma. In June, B-29s were based at a handful of airfields in Chengdu, China, that were just barely in range of a few targets on the southern tip of the Japanese islands. Logistically, this turned out to be enormously difficult. All of the fuel, ammo and supplies needed to keep the B-29s going had to be flown over the Himalayan “hump”—and it took three gallons of fuel to deliver one gallon to the Superforts.
It wasn’t until the capture of the Marianas in August 1944 that the B-29s were finally able to begin striking Japanese cities in force, from airbases that were hastily built on Tinian, Saipan and Guam. The first raids, in December 1944, were carried out at high altitude to avoid enemy fighters and anti-aircraft fire. But the pilots encountered an unexpected difficulty—the jet stream winds over Japan were so strong that the bomb-aiming computers could not accurately compensate for it. After several raids with mediocre results, Major General Curtis LeMay, placed in charge of the bombing campaign, switched tactics to low-altitude night attacks using incendiary bomblets. The Japanese had virtually no night-fighter capability, and their anti-aircraft guns were also of limited effect in the dark. So LeMay had all the gunners and turrets removed except the tail gunner, which allowed a bigger load of incendiaries. One by one, virtually all of Japan’s major cities were firebombed by over 100 B-29s at a time. The devastation was massive. In just one night raid on Tokyo, the bombers wiped out 15 square miles and killed 150,000 people.
On five separate occasions during these raids in 1944 and 1945, B-29s that had suffered battle damage or mechanical failure were forced to land in Soviet territory, near Vladivostok. As Russia was officially neutral in the Pacific War, these planes were interned, and while their crews were eventually released, the B-29s were kept by Stalin. Soviet technicians from the Tupolev design bureau took the Superforts apart and examined them in minute detail, then built their own versions using Soviet Shvetsov ASh-73 engines, designating them the Tupolev T-4 (with the NATO code name “Bull”). It became the USSR’s first strategic bomber, and it remained in Soviet service until the 1950s, with some 1200 built.
The US ceased production of the B-29 in May 1946, but the Superfortress continued to serve as the only nuclear-capable American bomber until the development of the B-50. B-29s also served in the Korean War in 1950.
There are about 25 surviving B-29s on display at museums, nearly all in the United States--though the Imperial War Museum in England has one. Two B-29s are still airworthy: “Fifi” is owned and operated by the Commemorative Air Force, and “Doc” is flown by a nonprofit group in Wichita, Kansas. The B-29A “Jack’s Hack” is on exhibit at the New England Air Museum in Connecticut, and the Castle Air Museum in California also has a B-29A. There are B-29s at the Museum of Flight in Seattle, the Barksdale Museum in Louisiana, the Museum of Nuclear History in Albuquerque, and the Pima Air and Space Museum. The most famous B-29, “Enola Gay”, is at the Smithsonian’s Udvar-Hazu center, and “Bockscar” (which dropped the A-bomb on Nagasaki) is at the US Air Force Museum in Dayton OH.
NOTE: As some of you already know, all of my diaries here are draft chapters for a number of books I am working on. So I welcome any corrections you may have, whether it's typos or places that are unclear or factual errors. I think of y'all as my pre-publication editors and proofreaders. ;)