The incredible North American XB-70 Valkyrie was fast, complex, and well ahead of its time. The project was also eye-wateringly expensive. Peter E Davies examines this innovative aircraft and the background to its eventual axing.
In January 2018 Boeing announced a new concept for a turbojet and ramjet-powered strike/reconnaissance aircraft capable of speeds up to Mach 5. Rivalling Lockheed Martin’s similar SR-72 Blackbird II, the twin-tailed, unmanned hypersonic Valkyrie II should outpace virtually all enemy defences if it is produced. Among many innovative design features its air intake configuration and its name derive from a North American design, conceived 60 years ago, which would have performed the same mission although at rather lower speed and without modern stealth technology.