History misses this plane--and for good reasons. //

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. //

out in the 1950s, only the older B-29s were called into perform non-nuclear strikes—where they suffered unexpected losses to Soviet MiG-15 jet fighters. With speeds approaching 680 miles per hour and high climb rates, the MiG-15 demonstrated that even the B-50’s higher speeds and altitudes were of little advantage due to advancing jet technology. This led to the cancellation in 1949 of an experimentally re-engined model first called the YB-50C with 4,500-horsepower engines.

However, the B-29 and B-50 by then were at the forefront of pioneering air-to-air refueling technology, which would allow the kind of extended range bombing raids the SAC was aiming for. Initially, this involved converting B-29s into KB-29s tankers, that would use a long hose to refuel nuclear-armed B-50s.

In 1949, the B-50A Lucky Lady II became the first aircraft to fly around the world in an epic ninety-four-hour flight between February 26 and March 2. (An earlier attempt by B-50 Global Queen, had to be aborted due to engine failures.) She was refueled by no less than four pairs of KB-29M tankers flying out of the Azores, Saudi Arabia, the Philippines and Hawaii along its 23,452 mile-long journey. This record would finally be beaten in 1956 in less than half the time by a brand-new B-52 jet bomber. //

The various B-50 variants were finally retired in the 1950s, their aluminum airframe aging poorly after seeing much hard use. A half-century later, the C-135 family of planes based on the 707 airliner continue to perform the numerous support roles the B-50 had pioneered—especially the air-to-air refueling technology which continues to undergird U.S. airpower into the twenty-first century.