Does True Air Speed (TAS) change with wind speed and direction?

My understanding is that if an aircraft were travelling at 470kt TAS, with a hundred knot tailwind, the ground speed would be 570kt. In this case the TAS would remain the same, regardless of the wind, but the ground speed would change.

  • 1
    $\begingroup$ True airspeed is relative to the air mass you are flying through, so yes, TAS is not affected by wind speed. $\endgroup$
    – Ron Beyer
    Sep 3 '16 at 22:53
  • $\begingroup$ Note that sudden changes of the wind speed do affect the TAS. Due to the inertia of the aircraft instantaneous changes in groundspeed are impossible. $\endgroup$
    – DeltaLima
    Sep 4 '16 at 20:32

Correct. True airspeed refers to the actual speed which the aircraft is moving through the air. Ground speed is the speed at which the aircraft moves over the ground. The formula

$v_\text{ground} = v_\text{true} - v_\text{wind} \cdot \cos(\alpha)$


  • $v_\text{true}$ is the true airspeed
  • $v_\text{ground}$ is the groundspeed
  • $v_\text{wind}$ is the magnitude of the winds aloft
  • $\alpha$ is the angle of the winds aloft relative to the longitudinal axis of the aircraft.

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