70,000 Feet and Mach 3 Performance Like No Other Bomber: The Sad Ending for the US Air Force XB-70 Valkyrie
Summary and Key Points: North American Aviation’s XB-70 pushed 1950s engineering to its limits. Six General Electric YJ93 turbojets made more than 172,000 pounds of thrust, a stainless-steel honeycomb skin shrugged off Mach 3 heat, and the wingtips folded …