Warplanes of the USA: North American XB-70 Valkyrie, USAF
North American XB-70A Valkyrie (USAF Photo) North American XB-70A Valkyrie. The futuristic XB-70A was originally conceived in the 1950s as a high-altitude, nuclear strike bomber that could fly at Mach 3 (three times the speed of sound). At that time, any potential enemy would have been unable to defend against such a bomber. By the early … Read more