Boeing B-29 Superfortress Designed in 1940 as an eventual replacement for the B-17 and B-24, the first B-29 made its maiden flight on Sept. 21, 1942. In December 1943 U.S. Army Air Forces leadership committed the Superfortress to Asia, where its great range made it particularly suited for the long over-water flights against the Japanese homeland from bases in China. | National Museum of the U.S. Air Force

The numbers on the B-29 are jaw-dropping, even today. A 141-foot wingspan, four massive piston engines, and five separate computer-controlled gun turrets all combined to make it a fearsome weapon. | Smithsonian Channel Aviation Nation