CAS increases.

difference between surrounding conditions and standard atmosphere must be known to deduce the CAS.variation.

CAS remains constant.

CAS decreases.

Often varies with changing indicated airspeed.

Often varies with changing air temperature.

Increases with increasing altitude.

Decreases with increasing altitude.

compressibility.

density.

instrument error.

position error.

overread in a climb and under-read in a descent.

overread.

underread.

underread in a climb and over-read in a descent.

TAS remains constant.

Mach number remains constant

Mach number decreases.

TAS decreases.

Pt - Pd

Pt-Ps

Pd-Ps

ps-pt

To provide visual indicators on the instrument panel for stall awareness.

To emit a loud sound to indicate a stall condition.

To shake the control wheel to alert the pilot of a stall condition.

To vibrate the control column to warn the pilot of the onset of stall.

temperature measured on the surface of an aircraft in flight, and is equal to or less than SAT.

ambient temperature measured outside an aircraft, and it CANNOT be higher than TAT.

average temperature measured outside an aircraft, and is equal to or less than TAT.

maximum temperature attainable by the air when brought to rest, and is equal to or less than TAT.