Mach 3+: NASA/USAF YF-12 Flight Research, 1969-1979

This publication provides a fascinating look at NASA's research program using the YF-12. Among the aircraft designs that transitioned from paper to hardware during the high-speed era, the Lockheed Blackbirds hold a unique place. The A-12, YF-12A, M-21, D-21, and SR-71 variants outperformed all other jet airplanes in terms of altitude and speed. To this day, they remain the only production aircraft capable of sustained cruise in excess of Mach 3. Developed in utmost secrecy, they eventually ...