[prmph]

Thanks for this explanation; quite interesting.

But it still seems to me that there might be a gravitational/inertial effects at play as well. At a (hypothetical) infinite altitude, it can no longer be said the the plane is moving perfectly in lock-step with the gravity/rotational acceleration of the earth. This implies the inertia of the plane relative to the rotation of the earth still has an effect at lower altitudes.

The effect might be tiny, but would be interesting to learn more about it nonetheless.

[BlueTemplar]

What gravity/rotational acceleration ?

Something like this does exist under general relativity :

https://en.m.wikipedia.org/wiki/Frame-dragging

However,

> This does not happen in Newtonian mechanics for which the gravitational field of a body depends only on its mass, not on its rotation.

[prmph]

Yes frame-dragging seems to be the name of the concept I was thinking of. Cool.