Great question. You see them flying around all the time but very few people know how!
So, the top of plane wings are actually curved and not flat like the bottom. As it moves and cuts through the air, the air on the top of the wing has to move a lot faster than the air on the bottom. Because of this the air on the top gets stretched and gets thinner, like a pair of tights! This means it is at lower pressure than the air below and the wing gets sucked upwards quite strongly. This is called “lift” and allows the plane to fly when it is moving forwards. When it stops, the pressures are the same and it falls!
Try this yourself. Take a sheet of paper hold it flat from one end only, letting it droop down. Then blow across the top of it: it lifts up because there is now higher pressure on the top of it! You’ve just made a plane wing, though a very tiny one!
Good point Shane! I travel loads but never actually stop to think about how I m actually being lifted up into the air. I ll add a little to Shane’s answer. Chuck a stone it rapidly drops to the ground, right? but then how do steel planes manage to fly?! it’s down to four basic aerodynamic forces: lift, weight, thrust and drag. You can think of them as four arms holding the plane in the air, each pushing from a different directions. Thrust, is the aerodynamic force that pushes or pulls the airplane forward (in our case, the planes engines). Drag is it’s opposing force that resists the motion. For flight to take place, thrust must be equal to or greater than the drag. Planes fly because they are able to generate ‘lift’ which normally moves the airplane upward and lift is generated by the forward motion of the plane through the air, which is produced by the thrust of the planes engines. I guess it’s easy to take the physics of flight for granted 😉 Great question!