Let me enter the fray on whether the earth pushes up on a wing. It is a
strange concept. First look at the case of a person shooting a pistol at
a tree. If the tree is hit both the tree and the shooter feel a momentary
force. Certainly the force felt by the shooter does not depend on whether
the tree is hit or not.
Now let's look at the situation of a propeller, which we know is a
rotating wing and thus obeys the same physics as a wing in flight. When
the plane is flying straight up, the momentum transfer is towards the
earth and the earth feels the net thrust of the propeller. In the case of
level flight the propeller is pointed parallel to the surface of the
earth. In this case the propeller puts a torque on the earth. Finally,
in a steep dive the propeller's momentum transfer is pointed away form the
earth. In this case the earth feels nothing. The propeller works equally
will in all directions. Its thrust does not depend on the existence of a
solid surface, but only on the density of the air.
The earth feels the weight of a plane because the momentum transfer
is down for level flight. It only cares what the density of the air is.
If the earth were replaced with a small black hole (which has no surface)
and additional air were added so that the density and pressure were
maintained at the present earth'surface radius, a plane would fly just
the same. It doesn't care if there is a solid surface below it.
Does the earth push on the wing? Since the air is not a solid, the
surface of the earth cannot communicate with the wing any faster than the
speed of sound. What about a jet at Mach 0.8, 35,000 feet above the
ground? Communication times are on the order of minutes. If it makes a
sudden turn does it fall out of the sky? Does a plane experience a small
drop in altitude when it flies over the edge of the Grand Canyon?