It wasn't that the X-1 would kill you, it was the systems in the X-1 that would kill you.
Chuck YeagerAs we went through mach one, the nose started dropping, so we just cranked that horizontal stabilizer down to keep the nose up. We got it above mach one, and once we got it above the speed of sound, then you have supersonic flow over the whole airplane, so you have no more shock waves on it that are causing buffeting...You really don't think about the outcome of any kind of a flight, whether it's combat, or any other kinds of flights, because you really have no control over it.
Chuck YeagerYou concentrate on what you are doing, to do the best job you can, to stay out of a serious situation. Thatโs the way the X-1 was.
Chuck YeagerLeveling off at 42,000 feet, I had thirty percent of my fuel, so I turned on rocket chamber three and immediately reached .96 Mach. I noticed that the faster I got, the smoother the ride. Suddenly the Mach needle began to fluctuate. It went up to .965 Mach - then tipped right off the scale ... We were flying supersonic. And it was a smooth as a baby's bottom; Grandma could be sitting up there sipping lemonade.
Chuck Yeager