Hello everyone.
Even simple situations can be not so easy to deal with. I ask myself a simple question and I haven't found an easy explanation.
Imagine a plane taking off from the north pole, and flying at 1000 km/h to the equator. When it arrives there it turns "right", in direction of the west, that is in the opposite direction of earth rotation (it is still flying at same proper speed of 1000 km/h).
The plane doesn't land during that time.
The very simple question is : what will be its speed relatively to the ground ?
At north pole it will have no angular momentum due to earth rotation, because it is located at the axis of earth sphere. Its speed relatively to the ground will then be 1000 km/h. During the travel to the equator, the ground beneath the plane is going faster and faster (due to earth rotation). So at the equator after turning to the west it will get a total speed of 1000 km/h (due to his propulsors) + a relative rotational earth speed of 1670 km/h = 2670 km/h !
That would make the plane to crash instantly, which is something that doesn't happen.
The main problem I see is that it seems that the earth has no mean to "communicate" its rotational speed to the plane which keeps flying at its original polar speed, that is 1000 km/h.