North American XB-70 Valkyrie

The North American Aviation XB-70 Valkyrie is a retired prototype version of the planned B-70 nuclear-armed, deep-penetration supersonic strategic bomber for the United States Air Force Strategic Air Command. Designed by North American Aviation in the late 1950s, the Valkyrie was a large six-engine, delta-winged aircraft able to fly Mach 3+ at an altitude of 70,000 feet (21,000 metres).