But how can you be sure of that unless you're calculating both in real time?
Quote:
Indicated Airspeed (IAS): The speed that your airspeed indicator inside the aircraft indicates, simple enough.
True Airspeed (TAS): This is your speed relative to the airmass through which you are flying. It differs from IAS because of pressure differences at different altitudes you are flying at. It is not necesarily your speed over the ground.
Forget the ShftZ readout and the HUD for a minute and look at the panel ASI only in flight -- what's it reading? IAS of course. Now which one between the HUD and the ShftZ are reading the same as the ASI? Then the other is most likely reading TAS.
Also, the ShftZ readout is hardcoded directly into the sim engine, but the HUD is controlled by independent gauges: CFSHUD.GAU and HUD.GAU. If by chance these were integrated into some aircraft addon's panel (can't happen with a ship) or influenced by another gauge used in an addon, you might get a change from what you're used to seeing.
Have you tried using the Settings feature for changing IAS vs TAS as i mentioned above?