What does CAS stand for in airspeed terminology?

What does CAS stand for in airspeed terminology?

• A. Calibrated Airspeed
• B. Indicated Airspeed
• C. True Airspeed
• D. Ground Speed

Answer: (A)

Calibrated Airspeed is the speed that has been corrected for instrument and installation (position) errors in the air data system. It takes the raw Indicated Airspeed reading and removes the biases introduced by the cockpit instruments and the way the pitot-static system is mounted in the airplane. This gives a speed that consistently represents the aircraft’s motion through undisturbed air. In practice, the airspeed indicator shows Indicated Airspeed, but for performance data and safe flight planning you use Calibrated Airspeed because it accounts for those instrument and mounting errors. True Airspeed would further correct for air density (altitude and temperature) to reflect actual speed through the air, and Ground Speed is speed over the ground affected by wind.

Calibrated Airspeed is the speed that has been corrected for instrument and installation (position) errors in the air data system. It takes the raw Indicated Airspeed reading and removes the biases introduced by the cockpit instruments and the way the pitot-static system is mounted in the airplane. This gives a speed that consistently represents the aircraft’s motion through undisturbed air.

In practice, the airspeed indicator shows Indicated Airspeed, but for performance data and safe flight planning you use Calibrated Airspeed because it accounts for those instrument and mounting errors. True Airspeed would further correct for air density (altitude and temperature) to reflect actual speed through the air, and Ground Speed is speed over the ground affected by wind.