What is indicated airspeed corrected for position error?

Calibrated airspeed is defined as the indicated airspeed corrected for position error. When an aircraft's airspeed is measured using the pitot-static system, certain discrepancies, known as position errors, can occur due to the placement of the pitot tube or the static ports. These errors arise from various sources, including airflow disturbances around the aircraft.

By correcting the indicated airspeed for these position errors, pilots arrive at the calibrated airspeed, which is a more accurate representation of the aircraft's actual performance in the air. This is crucial for flight planning, navigation, and ensuring safe operation within the aircraft's envelope.

In contrast, true airspeed refers to the actual speed of the aircraft relative to the surrounding air and takes into account the effects of altitude and temperature but does not specifically correct for position error. Grounds speed simply measures how fast the aircraft is moving over the ground, influenced by wind conditions and does not incorporate airspeed corrections. Equivalent airspeed is a concept that accounts for compressibility effects at higher speeds but does not relate to position errors as calibrated airspeed does.