Don't disagree with the general drift (
) of your post but Newton suffices. While Einstein extends our knowledge we don't need him for flying aircraft.
NEWTON
Inertial frame of reference - Wikipedia, the free encyclopedia
Contains this
The motion of a body can only be described relative to something else - other bodies, observers, or a set of space-time coordinates. These are called frames of reference. If the coordinates are chosen badly, the laws of motion may be more complex than necessary.
In air that is moving at constant velocity you have a good frame of reference for flying speed. It is a rubbish frame of reference for ground speed.
My hang gliding instructor used to say 'the ground is a dangerous place, stay away from it'.
