Definition
A chart, usually placed in the aircraft's Pilot's Operating Handbook or posted near the airspeed indicator, that shows the difference between indicated airspeed and calibrated airspeed across the aircraft's flap and configuration settings. It allows the pilot to correct the airspeed reading for installation and position errors that arise from how the pitot-static system is mounted on that specific aircraft.
Plain English
A small reference table for your aircraft that tells you how far off the airspeed gauge is at different speeds and flap settings, so you can work out the more accurate airspeed.
Context Anchor
Seen in an aircraft’s operating handbook or flight manual when comparing indicated airspeed with calibrated airspeed.
Derivation
‘Calibration’ comes from the Latin ‘calibrare’, meaning to measure or adjust to a known standard. The chart is the tool used to bring an indicated reading back to that standard.
Why Pilots Care
Using the chart ensures airspeed data is accurate for takeoff, landing, and flight planning, preventing speed mismanagement that could affect safety margins.
Intuition Check
Do not assume a calibration chart is a general performance chart. Here it is specifically a correction chart for an instrument reading.
Example Sentence 1
Before the short-field landing, she checked the calibration chart in the POH to confirm the corrected approach speed with full flaps.
Example Sentence 2
During preflight planning, reference to the calibration chart confirmed that the ASI reading needed a two-knot correction at approach speeds.