Aut cum scuto aut in scuto
Felix is a stud.
I thought the maximum attainable velocity by acceleration due to gravity, aka Terminal Velocity, was 120 mph.
I think you're right. This is simply a shock wave with moisture rich air - but it's still cool.
Or a photoshop job?
I'm skeptical. Who took the picture? Looks remarkably like the cone from a picture of an F-14 I've seen.
IFRC the speed will be effected by the density of the air. The higher up the faster you go, till air thickens up and "slows" you down to 120MPH.
Apparently he hit Mach 1.24, link above, which I should have put in in the first place (sorry).