# How is TAS affected by wind?

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.

• True airspeed is relative to the air mass you are flying through, so yes, TAS is not affected by wind speed. Sep 3 '16 at 22:53
• 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. Sep 4 '16 at 20:32

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