Russia panicked, u.s gigantic bomber could wipe out 150,000 Russian troops that stay on the border in five minutes. The north American XB-70 Valkyrie looked like it had been ripped straight out of the pages of a science fiction comic book.
With a sharp angular design, six afterburning engines, and the latest
targeting, navigation, and electronic warfare systems America could muster,
the Xb-70 was to become the world's biggest, fastest, and highest-flying
bomber in history.
Today the valkyrie serves not just as a reminder but arguably as the very
pinnacle of the cold war aviation philosophy of circumventing defenses
through ever higher and faster platforms.
The xb70 like America's famed state route 71 blackbird and its defunct
interceptor sister the YF-12, aimed to deliver on both in the classic
American style, by burning through budgets like jet fuel.
Born on the precipice of the missile age, the valkyrie may have become
America's go-to nuclear deterrent had the technology to build it been
available just 10 years sooner. But time waits for no man nor machine and
the Valkyrie was no exception.
A bomber designed so big its fuel tanks were the size of other bombers. the
program that was to eventually produce the air force's B-70 supersonic
bomber began in the mid-1950s, thanks to rapid advancements in the science
surrounding the supersonic flight.
In an incredible bit of irony, the XB-70 was intended as a replacement for
the brand new at the time B-52 Strato fortress, which despite having
incredible range and payload capabilities was already vulnerable to soviet
intercept fighters by the time it entered service in 1955.
Now nearly 70 years later, the XB-70 is merely one of the many bombers
to fail to dethrone America's mighty buff. A list that is soon to include
the retiring B-2 spirit and B-1B Lancer.
At the time the primary threats a bomber faced during a mission were
intercepted fighters and anti-aircraft guns, both of which could be
mitigated by simply flying higher than they could reach and faster than they
could shoot.
This approach while simple in theory created incredible engineering
challenges that would lead to some of the most exotic, dynamic, and capable
aircraft ever to take to the skies.
Initial designs for the XB-70 leaned on what engineers called the brute
force concept, which called for carrying an absolutely massive amount of
fuel for a long duration subsonic flight into soviet territory in an
aerodynamic design that was optimized for high performance during a
relatively short sprint through enemy airspace.
This approach led to absolutely massive concepts that leveraged external
fuel tanks that could be jettisoned once they were depleted. These tip tanks
may have been disposable but they were neither small nor cheap.
As a 1960 congressional report pointed out, each 191 thousand pound tip tank
was approximately the same size as America's existing B-47 strategic
long-range bomber.
When presented to legendary air force general Curtis Lemay, the man behind
America's B-29 bombing raids in the pacific theater of world war II, he
dismissed the massive 750,000 pound bomber outright.
With orders to go back to the drawing board, north America's team turned to
a recently published paper by Alfred J. Eggers and Clarence Silverstein from
the national advisory committee for aeronautics.
The innocuously titled document, aircraft configurations developing high
lift drag ratios at high supersonic speeds, explained that aircraft that
were designed from nose to tail for a single flight condition could
dramatically outperform those designed to compromise between both high and
low-speed flight.
In fact, it went on to prove that aircraft inlet and engine designs meant to
maintain high supersonic speeds could offer comparable fuel economy to
designs meant for subsonic operation.
In other words the paper offered the startling conclusion that the valkyrie
could reduce its fuel needs by a wide margin by adopting a specifically
high-speed design and then simply keeping the pedal to the metal so to
speak.
North American returned with a proposal for a bomber that was designed from
the ground up to fly the majority of its missions at Mach 3 and at 70,000
feet, though some sources claim 80,000.
In order to achieve and maintain these high speeds, their XB-70 was
actually designed to ride on the shockwave it produced at supersonic speeds,
using a delta wing, slab-sided fuselage, and a large triangular intake on
its belly positioned well ahead of the bomber's engines.
This angular intake allowed North American designers to intentionally
position the high pressure created by the shock wave on the bottom side of
the wings. In other words, the XB-70 would surf at Mach 3 on a shock
wave of its own creation.
