Generally speaking and contrary to popular belief, airplanes don't float on the air, they're sucked up into it. This reason is known as Bernoulli's Principle. It says: "...as air travels faster [than surrounding air] across a surface, the air pressure against it is reduced...". By curving the top of an airplane's wing, forming an airfoil, air above it has to travel farther (as the distance is greater) than the air below, forcing the air to move faster. The result is lower pressure on top and more pressure on the bottom. Another name for this is lift. The higher pressure below the wing is just like someone pushing from below the wing; the lower pressure above the wing is like someone pulling it up. Lift can help overcome the forces of gravity would pull the plane to almost certain destruction. If a wing has enough lift upwards, it moves upward, if a wing has lift downwards, it moves downward. Even though most paper airplanes have 'flat' wings, they still cause the air to move the same way. One plane that I built, the "Bernoulli Plane", has a real airfoil resembles the way that real planes and most birds fly. Unlike planes when a bird flaps its wings, air is pushed downward. This produces an opposite force that lifts the bird into the air. Since a bird's wing is in the shape of an airfoil, it
Generally speaking and contrary to popular belief, airplanes don't float on the air, they're sucked up into it. This reason is known as Bernoulli's Principle. It says: "...as air travels faster [than surrounding air] across a surface, the air pressure against it is reduced...". By curving the top of an airplane's wing, forming an airfoil, air above it has to travel farther (as the distance is greater) than the air below, forcing the air to move faster. The result is lower pressure on top and more pressure on the bottom. Another name for this is lift. The higher pressure below the wing is just like someone pushing from below the wing; the lower pressure above the wing is like someone pulling it up. Lift can help overcome the forces of gravity would pull the plane to almost certain destruction. If a wing has enough lift upwards, it moves upward, if a wing has lift downwards, it moves downward. Even though most paper airplanes have 'flat' wings, they still cause the air to move the same way. One plane that I built, the "Bernoulli Plane", has a real airfoil resembles the way that real planes and most birds fly. Unlike planes when a bird flaps its wings, air is pushed downward. This produces an opposite force that lifts the bird into the air. Since a bird's wing is in the shape of an airfoil, it