Boeing B-29 'Superfortress'
The B-29 'Superfortress' was a four-engine propeller-driven heavy bomber designed by Boeing that was flown primarily by the United States towards the end of World War II and during the Korean War. Boeing's B-29 Superfortress was the most sophisticated propeller-driven bomber of World War II and also equipped with a pressurized interior, allowing crewmen to fly long distances in relative comfort. Although designed to fight in the European theater, in December 1943, it was decided not to use the B-29 there as it was more suited to fly the long distances from China and the Marianas Islands to Japan and back. In the Pacific, B-29s delivered a variety of aerial weapons: conventional bombs, incendiary bombs, mines, and two nuclear weapons. The B-29 could carry more payload and fly faster than the Army's B-17 or B-24 heavy bombers.
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Development
The Boeing B-29 was designed in 1940 as an eventual replacement for the B-17 and B-24. The first one built made its maiden flight on Sept. 21, 1942. Developing the Boeing B-29 was a program which rivaled the Manhattan Project in size and expense. Technically a generation ahead of all other heavy bomber types in World War II, the Superfortress was pressurized for high altitudes and featured remotely-controlled gun turrets. Most important, its four supercharged Wright R-3350-23 engines gave it the range to carry large bomb loads across the vast reaches of the Pacific Ocean. Boeing submitted its Model 345 on 11 May 1940, in competition with Consolidated, Lockheed and Douglas. Boeing received an order for two flying prototypes, given the designation XB-29, and an airframe for static testing on 24 August 1940, with the order being revised to add a third flying aircraft on 14 December. An initial production order for 14 service test aircraft and 250 production bombers was placed in May 1941, this being increased to 500 aircraft in January 1942. The B-29 featured a fuselage design with circular cross-section for strength. The need for pressurization in the cockpit area also led to the B-29 having the only 'stepless' cockpit design, without a separate windscreen for the pilot, on an American combat aircraft of World War II. The first prototype made its maiden flight from Boeing Field, Seattle on 21 September 1942. Because of the aircraft's highly advanced design, challenging requirements, and immense pressure for production, development was deeply troubled. The second prototype, which, unlike the unarmed first, was fitted with a Sperry defensive armament system using remote-controlled gun turrets sighted by periscopes, first flew on 30 December 1942, this flight being terminated due to a serious engine fire.
On 18 February 1943, the second prototype experienced an engine fire and crashed. Changes to the production craft came so often and so fast that in early 1944, B-29s flew from the production lines directly to modification depots for extensive rebuilds to incorporate the latest changes. The United States Army Air Force(USAAF) operated modification depots struggled to cope with the scale of work required, with a lack of hangars capable of housing the B-29 combined with freezing cold weather further delaying the modification, such that at the end of 1943, although almost 100 aircraft had been delivered, only 15 percent were airworthy. The most common cause of maintenance headaches and catastrophic failures were the engines. Although the Wright R-3350 Duplex Cyclone radial engines later became a trustworthy workhorse in large piston-engined aircraft, early models were beset with dangerous reliability problems. This problem was not fully cured until the aircraft was fitted with the more powerful Pratt & Whitney R-4360 'Wasp Major'. The B-29 was capable of flight at altitudes up to 31,850 feet (9,710 m), at speeds of up to 350 mph (560 km/h) (true airspeed). This was its best defense, because Japanese fighters could barely reach that altitude, and few could catch the B-29 even if they did attain that altitude. Only the heaviest of anti-aircraft weapons could reach it, and since the Axis forces did not have proximity fuzes, hitting or damaging the aircraft from the ground in combat proved difficult.
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World War II
China and India
The initial plan, implemented at the direction of President Franklin D. Roosevelt as a promise to China and called Operation Matterhorn, was to use B-29s to attack Japan from four forward bases in southern China, with five main bases in India, and to attack other targets in the region from China and India as needed. B-29s started to arrive in India in early April 1944. The first B-29 flight to airfields in China (over the Himalayas, or "The Hump") took place on 24 April 1944. The first B-29 combat mission was flown on 5 June 1944, with 77 out of 98 B-29s launched from India bombing the railroad shops in Bangkok and Thailand. On 15 June 1944, 68 B-29s took off from bases around Chengdu, 47 of which reached and bombed the Imperial Iron and Steel Works at Yahata Japan. This was the first attack on Japanese islands since the Doolittle raid in April 1942. Starting in July, the raids against Japan from Chinese airfields continued at relatively low intensity. The attacks continued sparodically as fuel and ammunition supplies were available. On 2 November 1944, 55 B-29s raided Bangkok's Bang Sue marshalling yards in the largest raid of the war. B-29s were withdrawn from airfields in China by the end of January 1945 and was gradually shifted to the new bases in the Mariana Islands in the Central Pacific, with the last B-29 combat mission from India flown on 29 March 1945.
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The Marianas Islands
The B-29 could only reach a limited part of Japan while flying from Chinese bases. The solution to this problem was to capture the Mariana Islands, which would bring targets such as Tokyo, about 1,500 mi (2,400 km) north of the Marianas within range of B-29 attacks. It was therefore agreed between the US Navy and USAAF in December 1943 to seize the Marianas. Saipan was invaded by US forces on 15 June 1944, and despite a Japanese naval counterattack which led to the Battle of the Philippine Sea and heavy fighting on land, was secured by 9 July. Operations followed against Guam and Tinian, with all three islands secured by August 1944. In all, five major air fields were built, with two on the flat island of Tinian, one on Saipan, and two on Guam. Each was large enough to eventually accommodate a bomb wing consisting of four bomb groups, giving a total of 180 B-29s per airfield. These bases, which could be supplied by ship, and unlike the bases in China, were not vulnerable to attacks by Japanese ground forces, became the launch sites for the large B-29 raids against Japan in the final year of the war. The first B-29 arrived on Saipan on 12 October 1944, and the first combat mission was launched from there on 28 October 1944, with 14 B-29s attacking the Truk atoll. The first mission against Japan from bases in the Marianas was flown on 24 November 1944, with 111 B-29s sent to attack Tokyo. General Curtiss LeMay decided that a better and more effective method of attacking the Japanese cities was to do low level night bombing using incendaries to torch each Japanese city. Though it was designed as a high-altitude daytime bomber, in practice it actually flew more low-altitude nighttime incendiary bombing missions. It was the primary aircraft in the American firebombing campaign against the Empire of Japan in the final months of World War II.
The Atomic Bomb
On August 6, 1945, the Martin-built B-29-45-MO 'Enola Gay' dropped the first atomic weapon used in combat on Hiroshima, Japan. Three days later, 'Bockscar' dropped a second atomic bomb on Nagasaki, Japan. Enola Gay flew as the advance weather reconnaissance aircraft that day. A third B-29, 'The Great Artiste', flew as an observation aircraft on both missions.
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Korea
The B-29 was used in 1950-53 in the Korean war and at first, the bomber was used in normal strategic day-bombing missions, though North Korea's few strategic targets and industries were quickly reduced to rubble. More importantly, in 1950 numbers of Soviet MiG-15 jet fighters appeared over Korea (an aircraft specifically designed to shoot down the B-29), and after the 'Black Thursday' air battle, raids were restricted to night-only missions, largely in a supply-interdiction role. This happened after April 12, 1951, which was nicknamed 'Black Thursday' by USAF pilots after three MiG-15 squadrons (30 planes) attacked three squadrons of B-29 Superfortress bombers (36 planes) protected by about a hundred F-80 Shooting Star and F-84 Thunderjet fighters. With no casualties on the Soviet side, 12 B-29 bombers were destroyed(according to the Soviets, 3 according to the USAF with 7 damaged), however, regardless of the actual casualties, US sorties were halted for approximately three months afterwards, forcing US forces to change tactics like flying during night-time in small groups. Over the course of the war, B-29s flew 20,000 sorties and dropped 200,000 tonnes (180,000 tons) of bombs. B-29 gunners were credited with shooting down 27 enemy aircraft.
Production and Aftermath
The B-29 was the progenitor of a series of Boeing-built bombers, transports, tankers, reconnaissance aircraft and trainers including the B-50 Superfortress (the first aircraft to fly around the world non-stop) which was essentially a re-engined B-29. The type was finally retired in the early 1960s, with 3,970 aircraft in all built.
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P-26 Peashooter
P-36 Hawk
P-38 Lightning
P-39 Airacobra
P-40 Warhawk
P-47 Thunderbolt
P-51 Mustang
P-61 Black Widow
A-20 Havoc
A-26 Invader
B-17 Flying Fortress
B-24 Liberator
B-25 Mitchell
B-26 Marauder
