Military Hardware: Tanks, Bombers, Submarines and More Lockheed YF-12A Travelled at Mach 3.2 and 80,000 Feet But Ended Up Being Made Obsolete Thanks to Russian Missiles Lockheed’s YF-12A was a Mach 3.2 Cold War interceptor born from the same Skunk Works lineage that produced the A-12 and SR-71. Built to... Harrison Kass21 minutes ago