XB-70 Valkyrie

The XB-70 Valkyrie was North American Aviation’s experimental Mach 3 bomber prototype, originally tied to a high-altitude supersonic strategic bomber concept. Only two aircraft were built, and the operational bomber program was overtaken by changing air-defense realities and missile competition. Its development is a classic example of ambitious aerospace engineering meeting shifting strategy.

The XB-70 used a large delta wing and folding wingtips to exploit high-speed aerodynamic effects, including compression lift at Mach 3. NASA later used the aircraft as a testbed for supersonic transport and high-speed research. The page should explain the aircraft as both a canceled bomber and a research machine that produced valuable flight data.

The Valkyrie’s importance lies partly in why it failed as a weapons program: surface-to-air missile threats, ICBM development, cost, and changing doctrine reduced the value of high-altitude bomber penetration. It nevertheless remains one of the most important experimental aircraft ever built. For HiWars, the XB-70 page should frame technology, strategy, and cancellation together.