A friend and I were having a discussion. He says that if you are flying in a 50 knot headwind and the wind suddenly stops, the airplane will lose lift.
I say that this will not result in a loss of lift because, although the ground speed will change, the indicated airspeed does not change and no lift will be lost.
He then brought up microbursts and wind shear as an example of wind direction changing causing a change in lift, however I am not so sure. I think in those examples it is actual downdrafts pushing the plane down or the movement of air over the wing in a non-coordinated way, similar to how the air in a slip does not pass over the wing in a way that generates the most lift.
Does anyone have an answer? If an airplane is in a 50 knot headwind and the wind suddenly stops, will the airplane lose lift? What is the actual cause for loss of lift in a microburst or in wind shear?