The [i]North American Aviation[/i] [b]XB-70 Valkyrie[/b] was an experimental, large bomber jet made for a USAF requirement of a  nuclear-armed, deep-penetration strategic bomber for the Strategic Air Command of the U.S. Air Force during the 60s. Only two were built. 

The Valkyrie was a very advanced for its time six-engine bomber aircraft jet with [[canards]] capable of reaching Mach 3+ while flying at 70,000 feet (21,000 m). Its maiden flight was on 1964.

The program was canceled due to cost overruns, changing needs of the air-force, improvements in high-altitude surface-to-air missiles (SAMs), the introduction of intercontinental ballistic missiles (ICBMs) to the U.S. nuclear arsenal and the unfortunate mid air collision of one of the prototypes with an [[F-104 Starfighter]].

The remaining one served as a research plane for NASA before being retired to the National Museum of the United States Air Force in 1969.

h4. See also

* [[MiG-25]] - A [[Soviet]] [[fighter jet]] designed to intercept it.
* [[VF-1]]
xb-70