Mach #
Hello!
Speed of sound is directly Proportional OAT if the temp goes up so does the speed of sound & Tas. Suppose one is climbing with constant Mach # means he is decreasing the Tas. Descending with constant Mach mean increase in Tas. I hope that help a bit. Formula to calculate Local Speed of sound is 661.47 Square root 273.15+OAt / 288.15
Saeed