OK Nick. I acknowledge you as an expert so you are going to have to help me through this..... I had the same problem in senior physics when they told me that parallel lines meet and there is more than 360 deg. in a triangle.
I believe you I just want to understand it for myself.
Here's the thing. A couple of years ago I was flying down a gorge. It ran roughly N-S, it was about 1000' deep 1/2 mile wide and about 6 mile long & it wanders its way along. The wind was about 30knots from the southeast.
I was flying a kh4 inside the gorge doing about 55kias when I flew around a left hand bend into an area where the wind was being funnelled and my airspeed dropped to zero on the asi. Roll on throttle, lift collective, cyclic forward and cross fingers. Now the wind turned not me but either way it is the same to me ( I think)
The other problem I have is this
I'm flying north asi says 100 kias, gps says 60 knots now if I turn south but maintain my attitude and power etc initially my gps is going to say something like 60 knots still but the asi is going to say a lot less than 100 kias (isn't it ??) unless the turn is gradual and the airspeed increases whilst turning crosswind etc.
Now I read your last post and I know you said I was caught up in this reference to the earth thing but if I choose any fixed point anywhere surely I have one velocity relative to that point and the wind has a different one. Now if I change my velocity relative to that fixed point but the wind remains the same surely I have changed my velocity relative to the wind as well ?????? and if part of my aircrafts performance is dependant on airspeed then surely I have changed that as well.
Now I'm not saying you can feel this or see it at 20000' but isn't it still happening.
And if none of what I said happens then why do wqe worry about windshear.
Hope you can help Nick because from what I'm reading on this thread I obviously need it.