How Wings Work

Wings(Watch the video)—not engines—are what make an airplane fly. Although wings come in many shapes, they all produce lift by splitting the oncoming air, called the relative wind. Air flowing under the wing maintains its ambient pressure. Air flowing over the curved upper surface accelerates, and due to several factors, including Bernoulli's principle, drops in pressure. The difference between the relatively high pressure below a wing and the relatively low pressure above creates a force, called lift. Deflection of the air downward from the bottom of the surface of the wing also contributes to the total lift that a wing produces.

Pilots change a wing's lift by using the elevator to adjust the airplane's pitch attitude, and thus the wing's angle of attack (AOA).

Flight Path vs. Pitch Attitude

It's important to remember that the relative wind does not necessarily come from the direction in which the airplane's nose is pointed. For example, as the space shuttle glides in for a landing, its nose points well above the horizon, yet it's descending at a steep angle. Its wing flies at a very high angle of attack.