ORIGINAL: Mike SVOR
Well its not really true.
The curved top wing is designed to eliminate stall upon high angles of attack and slower than efficient speed over the wing.
There is some downward redirection of airflow going on here but at say 5 degrees of downward flow, this doesnt make the plane fly.
It's not the low pressure on top of the wing that makes a plane fly, it's the high pressure on the bottom of the wing that makes it fly.
Mike,
It is the pressure difference between the top and bottom surfaces that produces lift. It's specifically incorrect to say that it's the high pressure on the bottom of the wing that makes a plane fly. It is entirely possible, and not uncommon, for the pressure on the bottom of a wing to be lower than the ambient pressure of the air away from the wing. It is completely nonsensical in this case to say it is the high pressure on the bottom that is causing lift. Moreover, when airfoils are designed, it is common for the shape to be modified to give a specific pressure profile on the top surface. The pressure profile on the bottom surface is not generally considered.
It is more legitimate to characterize the top surface as the object of wing designers' scrutiny. In casual conversation, I would be inclined to say the top surface is the critical one, and the bottom surface is just along for the ride.
banktoturn