However, in those (1970) days of slick wings (no slats)
and the short gun fairing, I did see one F-4E come out
of phase and pull a mach 2.4 FCF before returning to
the flightline at Korat. Nobody believed it - so they
checked the TAS system. It was accurate. A dirty old
warbird from the Korat flightline could still pull 2.4
without any preparation (other than pylon/stores removal).

Skinny nose and -19 (??? IIRC) engines helped I'm sure.

R / John