500 feet - 500 knots USAF at the Mach Loop UK
https://en.wikipedia.org/wiki/Mach_Loop
UNITED STATES AIR FORCE low level training in the Mach loop, Wales.
F15E Strike eagles from LakenheathMC130 Hercules from Mildenhall and SpanghahlemCV-22 Osprey from Mildenhall