Mach number temperature generally decreases with increasing altitude between sea level and , the speed of sound also decreases. For example, the standard atmosphere model lapses temperature to at altitude, with a corresponding speed of sound (Mach1) of , 86.7% of the sea level value. While the terms "subsonic" and "supersonic", in the purest sense, refer to speeds below and above the local speed of sound respectively, aerodynamicists often use the same terms to talk about particular ranges of Mach values. This occurs because of the presence of a "transonic regime" around M = 1 where approximations of the Navier-Stokes equations used
Mach Loop Typhoon, Hawk jets and C-130J and Short Tucanoas well as U.S. Air Force F-15C Eagles, F-15E Strike Eagles, which are based at RAF Lakenheath in eastern England and MC-130 and V-22 Osprey from RAF Mildenhall. Many flight simulators have replicated the Mach Loop in Wales, but a notable one is present in the FlightGear flight simulator, created by the FGUK community as an add-on for the simulator, providing the player with the challenge of guiding aircraft at high speed through rings that mark the route. In addition, the scenario has "start" and "finish" points, and each run in the Mach