CAS to Mach speed
 

when do you switch from CAS to mach speed, at what altitude/ air speed.
does the PFD switchs automatically?.

where is TAS indicated?

this really bug me, the highest I have flown was 23000 feet and I got 120knots(Calibrated a/s) for a plane cruising at 165knots.
to get my TAS (substracted from my GS) I use the GPS.(my plane has lot of needles...)

could you give me more info, about airspeed in your real life as a pilot?

Dartagnan,
In a high speed jet or turboprop, you have a precomputed changeover altitude, wherby you transition from a constant IAS to Mach mo. in a climb, and vice versa in a decent.

i.e at what altiude will 280 KIAS =M .750. not the other way around .

CAS is used by the computer for TAS computations.
and if you want [doesn't sound applicable to your particular situation] Mach no
I'm a little confused by your question:confused:

hope that helps, there has been an immense amount of material written on Pprune recently about Speeds and Mach number try a search and you'll be greatly rewarded :ok:


To The Tire Speed Limit And Beyond:} :} :}
rhov:)