Pitchy. Try Mach Number. I guess you might be pulling a tad too much PI if you can achieve .5M
It's alongside the speed constraint in knots, is it not? Seperated by a /. ie 166/.3M. You can change either side of the constraint - just not much use to us.
@ 15 degrees C and MSL, 0.251Mach which rounded to one decimal point = 0.3M is 166kts.
Think of it in the same light as tonnes of fuel.
Useful huh?
Red