What it is: CAS sits between IAS and TAS in the airspeed chain. Your cockpit usually shows IAS, but checklists, flap limits, climb schedules and some reference speeds may be published as CAS because it removes errors caused by the pitot-static installation and the airspeed indicator itself.
In practice: During a simulated flight, you rarely dial in CAS directly unless the aircraft or its documentation specifically calls for it. What matters is that performance tables and operating limits may not line up exactly with the raw airspeed shown on the panel, especially in older aircraft or more detailed add-ons. A developer may model the conversion accurately, so a book speed given in CAS can require you to fly a slightly different indicated speed. At higher speeds and altitudes, aircraft may also switch from airspeed targets to Mach, which is a separate issue again.
Key considerations:
