Thanks for the correction, I did have that incorrect. TIL. Interesting follow-up -- from https://en.wikipedia.org/wiki/Sonic_boom https://en.wikipedia.org/wiki

Thanks for the correction, I did have that incorrect. TIL. Interesting follow-up -- from https://en.wikipedia.org/wiki/Sonic_boom https://en.wikipedia.org/wiki/Sonic_boom, the angle of the shockwave cone decreases (i.e. gets narrower) as the plane's velocity goes up. I'm wondering at what Mach number would the cone be tight enough that it doesn't intersect land?