Indicated airspeed

Indicated airspeed is the speed shown directly on the airspeed indicator from the pitot-static system, before corrections for instrument and position error. It is the speed reference used for many operating speeds such as climb, approach, stall and manoeuvring limits. As altitude increases, the same IAS corresponds to a higher true airspeed because the air is less dense. Pilots fly the published IAS values and monitor them carefully to stay within performance targets and structural limits.