Assuming ISA, +10C static air temp would be at 2525 ft pressure altitude - a TAS of 500KTAS would mean M0.763.
M0.763 at the same pressure altitude at +50C static air temp would imply ISA+40C and would require a TAS of 535KTAS.
Mach No. is the actual TAS divided by the local speed of sound.
Keeping it all simple, TAS = Mach No. x 38.97 x √ absolute static air temp
Last edited by BEagle; 9th Dec 2018 at 11:09.