Long before hitching a ride to the moon aboard Apollo 11, then US Air Force test pilot Neil Armstrong was zipping around in a rocket-powered North American X-15, which to this day remains the fastest manned, winged aircraft ever built. That flight record of Mach 6.72 or 7,274km/h was set by pilot William “Pete” Knight in 1967.
Now, some 59 years later, America still hasn’t ful...