What does indicated airspeed measure?

Indicated airspeed is defined as the speed of an aircraft as measured by the pitot-static system, specifically the air pressure reading from the pitot tube. The pitot tube measures the difference between the static pressure and dynamic pressure of the air as the aircraft moves through it. This measurement is crucial for pilot awareness because it provides real-time feedback on the aircraft’s performance and aerodynamic characteristics without being influenced by factors such as altitude or temperature.

Indicated airspeed is used to determine various performance parameters, including stall speed, maneuvering speed, and maximum operating speeds. It is an essential metric for flight safety, as it relates directly to the aircraft's performance capabilities in the current atmospheric conditions. Other parameters, such as ground speed or calibrated airspeed, are derived from indicated airspeed but are influenced by different factors.

Understanding indicated airspeed is fundamental for pilots as it affects their operational decisions and safety while flying.