What is calibrated airspeed (CAS) primarily corrected for?

Calibrated airspeed (CAS) is primarily corrected for indicated airspeed (IAS) and the pressure errors associated with the measurement of airspeed. Indicated airspeed is derived from the airplane's pitot-static system, which can be affected by factors such as sensor positioning and potential blockages in the system. CAS adjusts the indicated airspeed by taking into account the instrument error that occurs in the measurement due to these physical factors.

This correction is critical because it provides a more accurate representation of the aircraft's true airspeed through the atmosphere. While altitude, environmental factors, and navigation errors can also play a significant role during flight, they do not directly impact the calculation of calibrated airspeed as indicated airspeed adjustments do. Thus, the correct understanding of CAS ensures pilots have reliable airspeed information crucial for safe aircraft operation.