FGproperties/velocities/mach

description

This is a dimensionless factor, the plane speed divided by the sound speed, it's the norm of the speed from 3.0 fg version, was unclear before

main use

• The pitot tube use this to give dynamique pressure.
• it's used in some planes to display the mach speed, i recommend to make them use:

/instrumentation/airspeed-indicator/indicated-mach

conflict - solution

open

Yasim was giving the longitudinaly projeted mach velocity, and JSBSim the norm of the mach vector. this give false airspeed when alpha or beta are not nul. a solution is to use the mach norm for both, but we need some change in the pitot code, and more importantly, be sure that alpha and beta are ok, because we will need them. (btw, i don't know why beta is "side-slip" and alpha still "alpha" ...)