how does air and gravity contribute to flight?

Answer 1

wings are flat on the bottom, and bowed on the top, kinda like the shape of a drop of water sliding down an incline. as the plane flies, the air has to move much faster to move over the wing than the air going under the wing, which creates 'lift' since air moving faster has a lower pressure. when the force of the lift is more than the force of gravity, a plane will fly.

Answer 2

gravity doesnt except for the fact that it pulls the plane down lol, but basically what happens with planes is the wing is pointed upward and the air that hits it goes down, that creates a higher air pressure on the bottom of the wing than on the top which in turn creates the lift. As far as birds go well they are light enough to use the density of the air and actually push off of it with their wings

Answer 3

Without gravity the Airplane could not fly on earth.
the reason is as follow;The aiplane or bird flys because of the curvature of the wings. Its called air foil.
The wing experience a lift as a result of Bernouli's law and Newtons law.
The lift is a force and gravity is a force(the weight of theplane) on the wings. When the gravity force and the lift are equal the airplane can now move thru the Air at that particular elevation..