How do airplanes stay in the air?
Airplanes stay in the air because their wings create lift. As air flows over and under the curved, tilted wings, it produces higher pressure below the wing and lower pressure above.
Four forces act on a plane in flight: lift pushes it up, weight pulls it down, thrust from the engines pushes it forward and drag from air resistance holds it back. To fly level, lift must balance weight and thrust must balance drag. Engines push the plane forward fast enough for the wings to generate lift.
A wing is shaped and angled so that it deflects air downward. By Newton's third law, pushing air down pushes the wing up. At the same time, air speeds up over the curved top of the wing, lowering pressure there, as described by Bernoulli's principle. Both explanations describe parts of the same physics.
Control in the air
Pilots steer using movable surfaces. Ailerons on the wings roll the plane, the elevator on the tail tilts the nose up or down and the rudder turns it left or right. Flaps extend from the wings during takeoff and landing to create extra lift at slower speeds.
Did You Know?
The Wright brothers made the first powered, controlled airplane flight on December 17, 1903, near Kitty Hawk, North Carolina. It lasted just 12 seconds.