Indicated airspeed
Indicated airspeed is the speed reading shown by the airspeed indicator before applying any applicable instrument or installation corrections. It is commonly identified as IAS.
Reviewed 05.10.2026 · Version 2 · Scope: General
How to interpret it
It is not necessarily the same as true airspeed or groundspeed. Those quantities use different references and corrections.
Example
Hypothetical example: an aircraft may maintain the same indicated airspeed reading while its groundspeed changes with the wind. This illustrates different references without establishing flight procedures.
Why it matters to you
It helps distinguish aviation data that use the same unit but describe different speeds. Operating limits should be checked in the aircraft’s documentation.
Common points of confusion
IAS, true airspeed, and groundspeed are not synonyms. Changing the unit does not turn one of these quantities into another.
Documentary sources
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