I know airplanes and helicopters fly thanks to the same principle, the Bernoulli Principle. The wings and blades are designed so that the air travels faster across the up side than it does on the bottom side, generating an upward pressure, or lift. My question is... if the propeller rotates in reverse, does the pressure becomes downward? The distance the air has to travel from point A to B of the wing/blade is still the same so I would think that the way air moves around it do not matter. From the airplane perspective, I think this reverse rotation of the propeller would be equivalent to the airplane flying backward. So, what is the case here?
Thank you very much.