Everything You Need to Know About Different Types of Airspeed

Airspeed is a measure of the speed at which an aircraft moves through the air. There are different types of airspeed that pilots use for various purposes. Here are some common types of airspeed:

1. Indicated Airspeed (IAS)

Indicated Airspeed (IAS) is the airspeed read directly from the aircraft’s airspeed indicator. It is the uncorrected measurement of the dynamic pressure of the air on the aircraft’s pitot tube. IAS is used as a reference for various flight operations, such as takeoff, landing, and maneuvering.

2. Calibrated Airspeed (CAS)

Calibrated Airspeed (CAS) is the Indicated Airspeed (IAS) corrected for instrument and installation errors. Manufacturers provide correction tables or graphs to convert IAS to CAS, which accounts for factors like instrument errors, installation position errors, and other corrections specific to the aircraft. CAS is used to ensure accurate performance calculations.

3. True Airspeed (TAS)

True Airspeed (TAS) is the actual speed at which an aircraft is moving through the air. It is the calibrated airspeed corrected for non-standard atmospheric conditions, including temperature and pressure variations at different altitudes. TAS is important for flight planning, navigation, and performance calculations, as it represents the aircraft’s actual speed relative to the air mass.

4. Groundspeed (GS)

Groundspeed (GS) is the speed of an aircraft relative to the ground. It is the combination of true airspeed and the effect of wind. Groundspeed takes into account the aircraft’s true airspeed and the velocity of the wind, resulting in the actual speed at which the aircraft is moving over the ground. Groundspeed is important for flight planning, fuel calculations, and estimating arrival times.

It’s important to note that airspeed measurements can vary based on aircraft instrumentation, equipment, and environmental conditions. Pilots use these different airspeed types to ensure accurate performance calculations, maintain safe and efficient flight operations, and navigate effectively. The specific airspeed type to reference depends on the specific situation and the information required for a given phase of flight.