XB 70 Valkyrie US AIR FORCE ( USAF)

The North American Aviation XB70 Valkyrie was the prototype of the B70 nucleararmed, deeppenetration strategic bomber for the United States Air Force Strategic Air Command. In the late 1950s, North American Aviation designed the Valkyrie bomber as a large, sixengined aircraft capable of reaching Mach 3+ while flying at 70, 000 feet (21, 000 m). The USAF eventually gave up fighting for its production and the B70 program was canceled in 1961. Development was then turned over to a research program to study