"Defining Moment "

After dropping away from the B-29 on October 14th, 1947, pilot Chuck Yeager quickly lit off all the engine chambers and climbed on out to 35000 feet, then turned off 2 of the chambers. He continued climbing out to 42000 feet then relit the 3rd chamber. At Mach 0.92 he encountered buffeting, and the machmeter climbed to mach 0.97, then fluctuated off the scale. At that moment the speed of sound was broken for the first time, changing aviation forever. The maximum speed of the flight was Mach 1.07 (650 mph at 42000 feet).
 
 

Detail, "Defining Moment"