Definition
Adjusted or marked against a known reference standard so that the instrument's readings correspond accurately to the actual quantity being measured, with predictable corrections applied for known errors.
Plain English
Set up and checked against a trusted standard so the instrument shows the right number, with any built-in errors accounted for.
Context Anchor
Seen in instrument flying when flight instruments are described as being set to a standard, such as an airspeed indicator or altimeter.
Derivation
From the Latin 'calibra,' related to measuring the bore (caliber) of a gun barrel against a standard. The idea carried over into instruments: check it against a known reference and adjust until it reads true.
Why Pilots Care
Using a calibrated value prevents errors in performance calculations that affect stall margins, climb rates, and navigation accuracy.
Intuition Check
Calibrated does not just mean labeled, precise-looking, or high-quality. It means checked against a known standard and adjusted if needed so the indication is correct within the allowed small error.
Example Sentence 1
The airspeed indicator was recently calibrated, so the pilot trusted the readings during the approach.
Example Sentence 2
After the static system check, the altimeter was calibrated to read field elevation within 75 feet.