True Airspeed - Low-speed flight


The true airspeed (TAS; also KTAS, for knots true airspeed) of an aircraft is the speed of the aircraft relative to the airmass in which it is flying. The true airspeed is important information for accurate navigation of an aircraft.

At low speeds and altitudes, IAS and CAS are close to equivalent airspeed (EAS). TAS can be calculated as a function of EAS and air density

Related formulas


TAStrue airspeed (m/s)
EASequivalent airspeed (m/s)
ρ0air density at sea level in the International Standard Atmosphere (15°C and 1013.25 hectopascals) (density of 1.225 kg/m3) (kg/m3)
ρdensity of the air in which the aircraft is flying (kg/m3)