How do airplanes stay in the air?

An airplane wing is shaped so that air moving over it is deflected downward, and by pushing air down the wing is pushed up in reaction, producing lift. The curved upper surface and the angle of the wing both help direct air downward and lower the pressure above the wing compared with below it. To create enough lift, the plane must move forward fast, which is the job of its engines, whether propellers or jets. As long as lift is equal to or greater than the aircraft weight, it stays aloft. Pilots control climbing, descending, and turning by adjusting the wings surfaces and engine power.