Developed in the early 1960s under intense Cold War secrecy, the Lockheed SR-71 Blackbird became the fastest jet-propelled aircraft ever built, capable of exceeding Mach 3.3 at altitudes above 90,000 ...

Mach 3.08 At 74,000 Feet: The XB-70’s Peak Moment Summary and Key Points: The lone surviving XB-70 Valkyrie—North American’s Mach 3 strategic bomber prototype—sits at the National Museum of the Air ...