The Airspeed Indicator

Gauges The Cockpit

The airspeed indicator shows the aircraft’s speed (usually in knots ) relative to the surrounding air. It works by measuring the ram-air pressure in the aircraft’s Pitot tube relative to the ambient static pressure. The indicated airspeed (IAS) must be corrected for non-standard pressure and temperature in order to obtain the true airspeed (TAS). The instrument is color coded to indicate important airspeeds such as the stall speed, never-exceed airspeed, or safe flap operation speeds.