Indicated Airspeed (IAS)

The airspeed read directly from the airspeed indicator in the cockpit, without any corrections applied. IAS is derived from the difference between ram air pressure captured by the pitot tube and static atmospheric pressure from the static port. It is the speed most relevant to the pilot during flight because aerodynamic performance, stall speeds, and V-speeds published in the POH are referenced to indicated airspeed. IAS equals true airspeed only at sea level in standard atmospheric conditions; at higher altitudes, IAS reads lower than the aircraft's actual speed through the air.