Quiz time! Which secret American military project during World War II proved even more expensive than the $2 billion Manhattan Project which developed U.S. atomic bombs?
That would be the $3 billion B-29 Superfortress—the huge four-engine bomber designed to fly across huge distances and drop those atomic bombs.
The silver-skinned B-29’s four huge turbo-supercharged R-3350 Duplex Cyclone radial engines allowed the 37-ton aircraft (when empty!) to fly relatively fast at 290 to 350 miles per hour and at altitudes exceeding 30,000 feet, making it extremely difficult for Japanese interceptors to catch up with them.
But even as World War II ground on to its conclusion, the Air Force appreciated that the Superfortress’s advantages would soon vanish due to the advent of turbojet-powered fighters. As the Cold War gathered momentum in the late 1940s, it further became vital for the Air Force to have a nuclear bomber that could strike Russia from U.S. bases.
These needs culminated in a new B-29D model with engine power cranked up nearly 60 percent using a 3,500 horsepower R-4360 Wasp Major engine and a skin made of stronger but lighter 75-S aluminum alloy. Together, this lowered the weight of the wings by 600 pounds and increased speed to nearly 400 miles per hour. Other trimmings included a taller tail fin, hydraulically assisted controls, and wing and window de-icing systems.
The end of World War II saw the cancellation of B-29 orders. To rescue the program, the military redesignated the B-29D as the B-50 to imply the aircraft incorporated more original design features than was actually the case—hardly the first nor the last time misleading aircraft designations have been adopted for political purposes.
Only a small run of sixty B-50As were produced in Washington, and these went onto become the tip of the newly-formed Strategic Air Command’s nuclear deterrence fleet in 1948 until huge B-36 Peacemaker and B-47 Stratojet jet bombers could enter service.
A small number of B-50Bs were then built with lighter-weight fuel cells, until the Air Force settled on the B-50D to commit to larger-scale manufacture of 222 bombers. The last model downsized the crew from eleven to eight, had provisions for external fuel tanks, featured a simplified nose cone, and included a built-in inflight-refueling boom.