Why is the shape of the wing curved on the top and flat on the bottom?
The shape of the airfoil makes air travel a longer distance over the top of the wing, than under the flat bottom. This results in a lower pressure above the wing, which provides lift. With regards to the previous post: Yes, an airplane can fly upside-down. Once it’s in the air, and moving with some speed, a flat-plane wing or even an inverted airfoil can provide lift. That’s a different effect, A fan-blade pushes the air underneath it down, and the lifting force comes from the lower surface of the wing. An airfoil creates low pressure above it, and causes atmospheric pressure to lift the aircraft. They are two totally different phenomena, with different properties!
