Dear me !
Aren't we all getting our knickers in a twist? Poor old aquarium1 was only asking HOW the wind arrow was calculated and generated on the ground - a valid question, surely?
Can I just ask - having read the archived tech link - if, as some of you seem to be saying; the wind direction arrow is not to be relied on, why do Airbus display it? It is suppressed below 100 kts, so if it was unreliable they would suppress it until V1 or Vr, or until airborne.
We had a brown trouser moment some years ago taking off from Tobago in a heavyish A330. The man in the tower either gave us the wrong wind or his equipment was faulty. There were no windsocks in our visual field. Captain said nothing between 100kts and rotate, but when we got to rotate, I rotated but nothing much happened. ROTATE shouted Captain again and I hauled on the stick. After a brief struggle, we got airborne - with a significant tailwind, (that we were not expecting).
Now, I always try to glance at the ND wind arrow at 100kts, just to make sure we are not getting a repeat of that day. It is not difficult to do - you have just looked in at your PFD to confirm 100kts, so it is not difficult to glance at the top left of the ND then outside again.
Last edited by Uplinker; 12th Sep 2016 at 13:45.