Loaded up, the XB-70 was more than a half-million pounds of pure sex appeal. With a six-pack of afterburning GE YJ-93 engines, wingtips and snout rigged to droop—the former for speed, the latter for slower speeds—the supersonic beauty-70 looked like it was busting Mach with the parking brake set and chocks snugged around the tires.
It was a doomed design before North American even started cutting metal. The design was born from the Curtis LeMay school of logic that preached speed and altitude were a bomber’s best defense. But before it even flew, missiles brought it down, figuratively at least. As evidenced by the Soviets’ shootdown of Francis Gary Powers’ U-2, altitude was no longer a defense, and as technology improved, missiles could track faster and faster targets.
Presidential candidate John F. Kennedy argued for the design while campaigning for the White House, and the Air Force issued a contract for a dozen airframes in early 1960. Later that year, President Kennedy got briefed on missile capabilities and the Valkyrie’s associated weakness, and the order was slashed to three vehicles to be used for high-altitude, high-speed research. North American built and flew two of these birds, AV-1 and AV-2. AV-1 suffered plenty of teething issues associated with the construction process—North American was pioneering the use of stainless steel-skinned honeycomb structures, and more than once, AV-1 landed with panels missing that had peeled off at supersonic speed. AV-2, suffering significantly fewer structural issues, took flight and topped Mach 3. Construction of AV-3 was never completed.
No longer destined to be a high-altitude supersonic bomber, the XB-70 was now a flying laboratory. As researchers played with advanced aerodynamics, Washington pulled back the curtain for an aeronautic peepshow that astounded many—including the Russians, who reportedly designed the budget-busting Mig-25 Foxbat with the XB-70 as inspiration.
No longer a fighting aircraft, the XB-70 became a showpiece instead, though that visibility wound up killing the program. A formation photo flight in June of 1966 ended in tragedy. The speedy giant was flying in formation with an F-4 Phantom, an F-5, a T-38 and an F-104. After the photographers got their pictures, the F-104, flown by NASA Chief Test Pilot Joe Walker, got caught in the vortex off the XB-70’s right wingtip and was snapped up and across the Valkyrie, clipping both vertical stabilizers and the left wing. Walker died at the controls of his F-104. The XB-70 held its line for a long moment before it began to skid and disintegrate. The XB-70’s co-pilot, Carl Cross, died in the crash. Pilot Al White managed to eject to safety, with injuries. After the crash of AV-1, AV-2 flew on for another two and a half years before it made one last flight to Dayton, Ohio, where it stands as a crown jewel in the USAF Museum’s collection.
The Valkyrie helped provide us with a deeper understanding of high-altitude, high-speed aerodynamics. North American pioneered several construction methods in the process, and a generation of pilots and pilots-to-be were inspired by the image of a machine that may have just flown a little too high and fast for its time.
Want to get deep into the XB-70’s story? We recommend Valkyrie: The North American XB-70: The USA’s Ill-Fated Supersonic Heavy Bomber by Graham M. Simons, available as a Kindle e-book on Amazon.com.
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