First Prototype of the B-29
The B-29 Superfortress, the most advanced bomber produced during World War II, was the result of Boeing’s reaction to specification XC-218, which called for a bomber with a range in excess 5000 miles that could carry a bigger bomb load at higher speed than B-17B. Fortunately for Boeing, design work had been carried out on their next generation of heavy bombers over the preceding 2 years, and full scale mock up of model 341 had been produced. This was remarkably close to specification XC-218, and so with a small amount of rework, Boeing was able to submit their design.
Three prototypes were ordered and the first XB-29 flew in September 21, 1942. Meanwhile a priority order 1500 aircraft had been placed with Boeing following the Japanese attack on Pearl Harbor. The first YB-29 evaluation aircraft was delivered to the 58th Bombardment Wing in July 1943 and was followed 3 months later by the first batch of B-29 –BW production aircraft. The Superfortress had many advanced features including remotely controlled gun turrets and a partly pressurize fuselage.