How do planes fly?

Answer 1

try pilots

Answer 2

Well, basically, the wings provide lift and the propeller or jet engine pushes it forward. At low reynolds numbers like insect wings flat is the most efficient. This is why butterflies have thin, flat wings. At higher reynolds numbers a simple thin, curved shape is more efficient. Most small toy gliders have wings like this. The range that the Wright brothers flew in was low enough to allow wings similar to this. At higher speeds the reynolds numbers go up and then it becomes more efficient to have the classic airfoil shape. This generally has a nearly flat bottom and a curved top.

The whole purpose of an airfoil is to provide a lifting force without creating a lot of drag. You see things like this everyday. The blades on a fan are acting the same as an airfoil because they are pushing the air at right angles to the direction of travel. The sail on a sailboat does the same thing and enables a sailboat to sail sideways to the wind or into it at an angle. Obviously, fan blades and sails are curved but thin.

At higher reynolds numbers a simple thin, curved shape would create more drag for the same lift as a 3D airfoil. Lift over drag is how efficient the airfoil is. High lift with low drag is very efficient; low lift with high is very inefficient. The Space Shuttles are not very efficient gliders. When airplanes are designed to fly upside down a lot they use an airfoil that is nearly symmetrical so it is almost as good upside down. However, even airplanes that don't have symmetrical airfoils can fly upside down but the wing has to be at a much greater angle of attack and it creates much more drag.

In one of the early tests of an unmmaned glider the Wright brothers discovered that it would only fly with the nose up very high at a high angle of attack. This was the point when they first questioned the data that Lilienthal had given them. After a simple test using an airfoil and a flat plate mounted on a bicycle wheel they realized that Lilienthal's tables were wrong. They then built their own wind tunnel and did their own airfoil testing. This is how they chose an airfoil for the Wright Flyer. They had a windtunnel that delivered enough air velocity. However, what they didn't know was that reynolds numbers increase with longer airfoils. So, their scaled model was not completely representative of their full sized aircraft and the airfoil could have been improved a little.

I recall in school that our teacher was not as knowledgable about this as she perhaps should have been and she claimed that they tested all of their airfoils on the bicycle wheel when actually it was just a single quick test. When that test failed they built a windtunnel and later a better windtunnel.

The Wrights built roughly 1/3 size glider models first, then a glider large enough to carry a person's weight. Then with enough data they were able to calculate the necessary wing area to have enough lift to fly with the weight of the engine and the pilot. All this testing took several years.

On the theory of what causes lift. Well, although many people talk about the relative speed and changes in pressure the simplest thing to say is that the wing acts to curve the airflow downward. As the air is turned downward it pushes the wing upward in the opposite direction giving it lift. It isn't that complicated really, it is the same effect as when you turn the rudder of a boat. The rudder deflects the water to one side and this pushes the back of the boat in the opposite direction.

Answer 3

Planes have wings. The wings have a particular shape which creates higher air pressure under the wing than above it. This pressure differential provides "lift." Provide enough lift by providing enough airflow across the wings and the plane will fly.

How do you make sure that you have enough airflow passing across your wings? The Wrights tried to mount an engine on a double winged frame and it flew.

Everyone was amazed, eventually.

It happened in North Carolina or somewhere like that.

Answer 4

air is pushed under the wings at high speed (take off) which makes the plane go up the air. the plane always flies nose upwards so the wind is continuously under the wings and usually travels around 500 miles an hour for a shorthaul plane which keeps the aircraft airbourne.

Answer 5

Engines push plane forward. That and wind pass air over the wings.

The wings are shaped to be curved on top and flat on bottom (ie more surface area on top than underneath. Because of this, the air on the top of the wing has to pass faster over the top of the wing than the bottom (because it has further to go in the same time).

Where you have areas of unequal speed, there is lower pressure where there is higher speed. That means the top of the wing has lower pressure than the bottom, so the air itself pushes the plane upwards. Enough speed and you take off.

That is the basics of aeodynamics, anyway.

Hope this helps.

Answer 6

You can do a dead simple test to demostrate the effects. Nest time you go out in a car, stick your hand out the window and lay it flat. The rotate your wrist and you'll feel the air pressure try and pull your hand up & down. This is exactly how a plane flies just on a bigger scale.

Answer 7

Aerodynamic wind pressure. The way the wings are formed allows air to flow evenly on the bottom for lift, and the curved top reduced wind resistance.

Answer 8

If it's the shape of the wing that keeps them up how come some of them can fly upside down?

Answer 9

actually it is speed across the bottom of the wing, that makes above the wing creat a low pressure area, thus high presure on the bottom, pushes the plane to the low pressure above the wing,

Answer 10

The airflow across the wing creates a vacuum which the wing rises to fill= flight

Answer 11

They are covered with that shiny dust you get when you swat a moth.


(don't worry, somebody sensible will give you an answer to do with the shape of the wing and air moving faster under it then over it or some c**p like that, just thought I'd get the stupid one in.....there you go, this bloke after me knows what he's talking about......)