True Airspeed - High-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.

TAS can be calculated as a function of Mach number and static air temperature as shown.

Related formulas


TAStrue airspeed (m/s)
a0speed of sound at standard sea level (661.47 knots) (m/s)
MMach number (dimensionless)
Tstatic air temperature in kelvin (K)
T0temperature at standard sea level (288.15 K) (K)