What type of correction must you apply to indicated airspeed (IAS) to calculate true airspeed (TAS)?

To calculate true airspeed (TAS) from indicated airspeed (IAS), a density correction is required. IAS is the speed indicated by the aircraft’s airspeed indicator, which is uncorrected for air density variations. As aircraft altitude increases, the air becomes less dense, affecting the air pressure against the aircraft's pitot tube, which measures IAS.

To convert indicated airspeed to true airspeed, one must account for the actual density of the air at the aircraft's altitude, which is lower than at sea level. The true airspeed reflects the actual speed of the aircraft through the air mass, and since IAS does not account for variations in air density caused by altitude and temperature, a density correction is essential for an accurate conversion.

This correction is particularly important during flight at higher altitudes where the air density is significantly low compared to standard atmospheric conditions at sea level. In determining true airspeed, it ensures that pilots have the accurate data needed for navigation and performance calculations.