When I flew Navy fighter aircraft, the u201c250kt under 10,000 ruleu201d was waived by the FAA. So we did not have a u201cspeed limitu201d (although if we exceeded Mach I, we would hear about it, if that occurred over land.)We routinely flew around 300kts on all climb outs and descents. Low level military training routes are usually limited to 420 knots, and flown below 1,500 feet/457m above the ground.Although it is not done anymore, we used to fly into the Naval Air Stationsu2023 overhead patterns (the u201cbreaku201d) at over 400 KIAS and maybe 4u20136 Gs turning downwind to bleed off the excessive speed.On my last flight with the Navy I was just under supersonic coming back from the desert to land. ATC cleared me for the descent into NAS Miramar. The controller having noticed my unusual and excessive speed, he then jokingly told me to, u201ckeep the speed up.u201d So I did all the way down since the airspace was clear. Wow, what a ride! It was tough getting that F-14 slowed to approach speed to land!