Real interesting pair. Welsh, after becoming an ace in the Pacifc theater, became a test pilot for North American, where he flew the prototype of the F-86. Indeed, it is now generally conceeded that he took that prototype supersonic before Chuck Yeager went Mach 1 in the X-1
He also became the first pilot of the F-100 prototype (the first fighter capable of going supersonic in level flight), a job that got him killed in 1954 when yaw problems led to a breakup at supersonic speeds.