[gandalfu]

No trolling, It seems to me the airplane does not have enough surface area (sail) to be pushed by the wind.

My final conclusion is relative movement, the jet stream is moving at speed X vs the ground and the airplane at speed Y vs the surrounding wind, the airplane moves then at speed X+Y vs the ground.

My question is now, a GPS based speedometer will read X+Y speed. A wind based one will read just X.

I should have asked if the airplane is moving faster vs the surrounding wind.