Definition
Calibrated airspeed is the indicated airspeed of an aircraft, corrected for installation error and instrument error. At sea level in standard atmospheric conditions, calibrated airspeed equals true airspeed.
Plain English
It is the airspeed shown on the cockpit gauge after small built-in errors from how the airspeed system is installed and how the instrument itself reads have been corrected. It gives a more accurate picture of the airplane's speed through the air than the raw indicated reading.
Context Anchor
Seen in airplane performance charts, airspeed correction tables, and discussions that compare what the airspeed indicator shows with corrected airspeed values.
Derivation
Calibrated comes from the Latin idea of marking out a measuring scale to a known standard. To calibrate an instrument is to adjust or correct its readings so they match true values. So calibrated airspeed is airspeed that has been corrected against a known standard.
Why Pilots Care
Using calibrated airspeed gives accurate numbers for aircraft performance, climb rates, and stall margins.
Intuition Check
Calibrated does not mean perfect or error-free. Here it means the indicated airspeed has been corrected for known errors in the airplane’s airspeed system.
Example Sentence 1
The stall speed listed in the POH is given in calibrated airspeed, so the pilot checked the airspeed correction table to see what the indicator would actually read.
Example Sentence 2
After applying the correction factors, the indicated airspeed became the calibrated airspeed needed for the true airspeed calculation.