The World’s Fastest Bomber: The XB-70 Valkyrie

This video was made possible thanks to CuriosityStream. Watch thousands of high-quality documentaries and get access to my streaming service, Nebula, using the link in the description. In the fall of 1964, the Air Force begins testing a radically new machine that appears to come from outer space. It is one of the

fastest

planes ever flown, a huge intercontinental

bomber

that can outrun any fighter jet. An aircraft so innovative that it uses its own supersonic shock wave. It was to be America's future

bomber

force. But efforts to develop such an advanced aircraft would be marred by tragedy. By the mid-1950s, tensions between the United States and the Soviet Union were reaching their highest point.

Both sides had strategic bombers that could fly to the other side of the

world

to attack targets deep in enemy territory. The United States had developed a state-of-the-art bomber force composed exclusively of jet aircraft. The newly introduced B-52 could carry large payloads over long distances, and the soon-to-be-introduced B-58 would reach supersonic speeds. But in an all-out conflict, none of these would really be enough against Soviet air defenses. While the B-52 could fly to the Soviet Union, it flew too slowly to stand a chance against the latest generation of Soviet interceptors. The supersonic B-58 could fly as fast as any interceptor, but had limited range and payload.

What the Air Force urgently needed was a new type of aircraft. A heavy bomber fast enough to outrun anything the Soviets could throw at it. But in 1955, many doubted that such an aircraft was possible. Because it would mean having to resort to quite radical solutions. Like using nuclear energy to extend the range of an airplane, or exotic high-energy fuels to increase the performance of jet engines. The most practical solution seemed to be a plane that would fly subsonic most of the way to its target before shedding the outer parts of its wings and fuel tanks for a supersonic run.

But aviation technology in the 1950s advanced at breakneck speed, with rapid advances in aerodynamics, engine performance and exotic materials. And it meant that the board concept could be shelved in favor of a design that would cruise supersonically throughout its mission. So in 1957, the Air Force began developing a next-generation bomber. And the performance goals were ambitious. It would have to fly more than three times faster than the B-52, twenty-five thousand feet higher, and have a similar payload and range. Major aircraft builders Boeing and North American Aviation were invited to compete on a design. Boeing and North American presented radical concepts that seemed similar on the surface.

Both featured cunards and thin delta wings optimized for supersonic flight. But Boeing was widely expected to win. After all, they had built the venerable B-52 and a series of iconic bombers during World War II. North America was the loser. But during development, its engineers stumbled upon research that would give them a huge advantage. A little-known report that detailed a phenomenon called compression uplift. When flying faster than the speed of sound, shock waves typically move away from an airplane. But if they could be redirected under the wings, the shock waves would help generate additional lift. Using this principle, the North American entry promised to fly more efficiently at high supersonic speeds.

And the Air Force was impressed. To Boeing's surprise, in 1957 the North American design was selected for development. The new bomber would be named Valkyrie and designated the B-70. Engineers used cutting-edge technologies to build a 260-ton bomber that could outrun a fighter jet. To make this feat possible, six afterburning turbojets received air through a sophisticated inlet. The engines were optimized to operate more efficiently at high supersonic speeds. And they were powerful enough that even if one failed, the Valkyrie could maintain Mach 3 and still complete its mission. But clever aerodynamics were also key to performance, as compression lift gave the Valkyrie one of the highest lift-to-drag ratios of any manned aircraft.

Variable geometry wings improved stability and improved compression lift. During takeoffs and landings it could be fully extended. At low supersonic speeds, with a descent angle of 25 degrees, and at multimach speeds, a total of 65. But flying at three times the speed of sound, the kinetic heating of the airframe would be so intense that it would soften the aircraft aluminum. conventional. So engineers developed a revolutionary fuselage skin and circulated fuel throughout the fuselage to cool the plane's interior. Even at an altitude of seventy-five thousand feet, the Valkyrie's cabin was fully pressurized and featured an innovative encapsulated exhaust system.

It meant the bomber's four-person crew would not have to don bulky flight suites, allowing the Valkyrie crew to take off in just 20 minutes. Capable of delivering a nuclear payload to any part of the

world

in just a few hours, the Valkyrie's performance was truly out of this world. And the bomber would embody the American strategy of deterrence through force. The first experimental XB-70 prototype was presented in May 1964 and flight testing would begin in the following months. And soon a second and third prototype would be added, both already under construction. But from the beginning it was clear that things would not go so well.

During initial ground testing, there were so many technical problems that the first flight was delayed for months while engineers resolved a long list of problems. It would not be until September 21 that the XB-70 was finally ready to make its first flight. And cheers were heard as the space-age bomber took off for the first time. But the celebrations were short-lived. Because a hydraulic leak prevented the landing gear from retracting. And soon one of the engines revved, forcing it to be shut down. As the prototype returned to land, a brake locked, causing a tire to explode and catch fire.

It seemed that when one problem was solved, more arose. On October 12, the It seemed as if he had flown through it. a sandblaster The paint was repaired and the XB-70 moved forward at higher speeds. But with each test flight, it seemed that the faster I flew, the more serious the problems became. On its twelfth test flight, when the prototype reached Mach 2.6, the horizontal divider detached and was sucked down the engine duct, disabling four engines. The pilots landed safely, but all the engines had to be replaced. Finally, on October 14, the plane was cleared to reach Mach 3. But just two minutes later, a large portion of the wing's leading edge broke off, forcing another emergency landing.

From that moment on, the first prototype was limited to flying at no more than Mach 2.5. In the development of such a modern aircraft, setbacks were inevitable. But there was a much bigger problem looming over the program. From the beginning there were serious doubts about whether the Valkyrie would really be safe from Soviet air defenses. Because surface-to-air missiles, introduced in the mid-1950s, were quickly becoming the most effective way to protect airspace. And in the 1960s, the Soviet Union had thousands of them, which could hit targets even beyond the XB-70's altitude. The introduction of intercontinental ballistic missiles in the late 1950s also meant that nuclear warheads could now be delivered much more quickly and cheaply.

In the span of just a few years, missile technology had rendered the world's most advanced bomber virtually obsolete. With the strategic value of the XB-70 in serious doubt, engineers looked for ways to keep the aircraft relevant. Look for radical concepts to reuse the bomber and convert it into a missile launcher, an aerial launch platform for spacecraft or even a supersonic aerial refueler. Even more extravagant was the proposal to convert the bomber into a Mach 3 supersonic transport. But these concepts proved to be a bridge too far. And the program was drastically scaled back, eventually reduced to a minimal research project involving just two aircraft.

But since millions had already been spent on development, the program moved forward. And in 1966, NASA joined the Air Force in flight testing. Use the prototypes to gather valuable research on supersonic flight. By this time, the second prototype had proven to be a much more capable aircraft. On May 19, 1966, it reached speeds exceeding Mach 3, demonstrating its ability to cruise at 3 times the speed of sound for 30 minutes. After nearly a decade of development, one of the world's most ambitious aircraft was finally living up to expectations. But tragedy would come just a few weeks later. On June 8, the second prototype was joined by four other aircraft for a formation flying photo session.

But minutes into the flight, without warning, one of the following aircraft collided with the XB-79, destroying it instantly and severely damaging the Valkyrie's vertical stabilizers. For 16 seconds, the Valkyrie continued to fly straight and level before spiraling back to earth. In a matter of seconds, two test pilots and a billion-dollar plane were tragically lost. It was a devastating setback for the program and meant that NASA and the Air Force would have to continue research with the much less capable original prototype. The XB-70 was an engineering marvel. And although he never joined the American bomber force, he still had a profound impact on the Cold War.

Because in 1955, when the Soviet Union learned that the Americans were developing a long-range supersonic bomber, they rushed to develop an equivalent. And it would end up being one of the scariest airplanes ever built. But appearances can be deceiving. In an effort to match the Americans, the Soviets ended up producing an embarrassing failure. One they would keep hidden for decades. You can learn more about the dramatic failure of the M-50 in my latest video available right now on Nebula. Nebula is where you see the most Mustard videos, like my video on the legendary F-117 Nighthawk or MiG-31 Foxhound.

And it's where you can enjoy exclusives from other creators, like Real Engineering's incredible new Battle of Britain series, or nearly three hours of exclusive Nebula content from Real Life Lore. The best part about Nebula is that it's free when you sign up for CuriosityStream. A streaming service with thousands of big-budget, award-winning documentaries. One of my recent favorites is Finding the Graf Zeppelin, a fascinating documentary about the German World War II aircraft carrier, at the time the largest in the world. You'll learn why it was Germany's first and last aircraft carrier. Get unlimited access to CuriosityStream and Nebula for less than $2 a month by going to Curiositystream.com/mustard and use promo code "mustard" when you sign up.