<P> The crew enjoyed, for the first time in a bomber, full - pressurization comfort . This first - ever cabin pressure system for an Allied production bomber was developed for the B - 29 by Garrett AiResearch . The nose and the cockpit were pressurized, but the designers were faced with deciding whether to have bomb bays that were not pressurized, between fore and aft pressurized sections, or a fully pressurized fuselage with the need to de-pressurize to drop their loads . The solution was a long tunnel over the two bomb bays so as not to interrupt pressurization during bombing . Crews could crawl back and forth between the fore and aft sections, with both areas and the tunnel pressurized . The bomb bays were not pressurized . </P> <P> In September 1941, the Army Air Forces plans for war against Germany and Japan proposed basing the B - 29 in Egypt for operations against Germany as British airbases were likely to be overcrowded . Air Force planning throughout 1942 and early 1943 continued to have the B - 29 deployed initially against Germany, only transferring to the Pacific after the end of the war in Europe . By the end of 1943, however, plans had changed, partly due to production delays, and the B - 29 was dedicated to the Pacific Theater . A new plan implemented at the direction of President Franklin D. Roosevelt as a promise to China, called Operation Matterhorn, deployed the B - 29 units 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 . The Chengdu region was eventually chosen over the Guilin region to avoid having to raise, equip, and train 50 Chinese divisions to protect the advanced bases from Japanese ground attack . The XX Bomber Command, initially intended to be two combat wings of four groups each, was reduced to a single wing of four groups because of the lack of availability of aircraft, automatically limiting the effectiveness of any attacks from China . </P> <P> This was an extremely costly scheme, as there was no overland connection available between India and China, and all supplies had to be flown over the Himalayas, either by transport aircraft or by the B - 29s themselves, with some aircraft being stripped of armor and guns and used to deliver fuel . 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 elsewhere in Thailand . Five B - 29s were lost during the mission, none to hostile fire . </P> <P> On 5 June 1944, B - 29s raided Bangkok, in what is reported as a test before being deployed against the Japanese home islands . Sources do not report from where they launched, and vary as to the numbers involved--77, 98, and 114 being claimed . Targets were Bangkok's Memorial Bridge and a major power plant . Bombs fell over two kilometres away, damaged no civilian structures, but destroyed some tram lines and destroyed both a Japanese military hospital and the Japanese secret police headquarters . On 15 June 1944, 68 B - 29s took off from bases around Chengdu, 47 B - 29s bombed the Imperial Iron and Steel Works at Yawata, Kyoto Prefecture, Japan . This was the first attack on Japanese islands since the Doolittle raid in April 1942 . The first B - 29 combat losses occurred during this raid, with one B - 29 destroyed on the ground by Japanese fighters after an emergency landing in China, one lost to anti-aircraft fire over Yawata, and another, the Stockett's Rocket (after Capt . Marvin M. Stockett, Aircraft Commander) B - 29 - 1 - BW 42 - 6261, disappeared after takeoff from Chakulia, India, over the Himalayas (12 KIA, 11 crew and one passenger) This raid, which did little damage to the target, with only one bomb striking the target factory complex, nearly exhausted fuel stocks at the Chengdu B - 29 bases, resulting in a slow - down of operations until the fuel stockpiles could be replenished . Starting in July, the raids against Japan from Chinese airfields continued at relatively low intensity . Japan was bombed on: 7 July 1944 (14 B - 29s), 29 July (70 +), 10 August (24), 20 August (61), 8 September (90), 26 September (83), 25 October (59), 12 November (29), 21 November (61), 19 December (36) and for the last time on 6 January 1945 (49). </P>

1945 b-29 superfortress bombers begin to drop supplies into allied prisoner of war camps in china