How to Make a Paper Airplane Cont Furthur.

Paper Craft:

Paper folding looks almost effortless in the animations but can be frustrating with real paper. Even a reverse fold on a rudder which looks simple requires patience and some practice. Expect to learn about a plane by folding it several times and save your best effort (and paper) for last.

Most folds involve corners and edges so the creases can be made exact. Others like the main wing fold of most planes can only be described as "about there". These folds are doubly difficult because they usually include many many layers of paper. By trying the folds different ways to see the effect on the airplane, the best way for each craft can always be found.


Basic Aerodynamics:

The study of forces that affect an object moving through air is known as aero-dynamics. The same forces that allow kites and gliders to fly apply to paper airplanes and real airplanes as well. In fact, all objects are affected as they move through air or air moves past them. Designers or airplanes, sailboats, race cars and even buildings rely on the same principles of aerodynamics.

For airplanes, we consider 4 basic forces:

gravity
thrust
drag
lift

Now, if your interest in airplanes only goes as far a booking your holidays though fly.com or Expedia, you might not be interested in the details, but it is always good to have a basic understanding. If you are an avid paper plane-maker or you plan on getting a pilot's license then you might want to make understanding aerodynamics a priority! Let's start with gravity. Gravity is a constant force that pulls the plane toward the ground. Thrust usually comes from an airplane's engine but paper airplanes get thrust from you throwing them. Drag is the opposing force to thrust and is caused by friction of the plane's skin with air. Drag slows the plance reducing the wing's ability to generate lift.

Lift is created when moving air above a wing creates lower pressure. A Swiss mathematician, Daniel Bernoulli, discovered this effect which you can demonstrate. Tape a piece of paper to a table edge and blow across it at lower pressure that the still air below it. This slight pressure difference causes the paper to rise.

The same principle applies to curved wings found on real airplanes. Air moving over the top of the wing has to travel slighty farther (and so a little faster) than the air beneath it. This causes slighty lower pressure above the wing which creates lift. The best wing shape for lift depends on many things and usually is designed using a computer and a wind tunnel.

Paper airplanes don't have curved wings so how do they fly? They use the angle of attack of their flat wings to create lift. Even though the paper wings are flat, you will notice that air movig across the top surface has to travel slightly farther (and faster). Lift is generated from the same low pressure (Bernoulli effect) as with a curved wing although not nearly as much.

The total amount of lift also depends on air speed and wing size. Airplanes can fly only when total lift is large enough to counteract their weight. Since all the airplanes in this program weigh about the same, those with smaller wings fly faster. This happens because larger wings can generate enough lift even when they are flying more slowly.


Common Folds:

When making paper airplanes, it is very common to fold something in half. Often it's the whole sheet but many times it's a flap or a large diagonal. Fold things in half as accurately as you can. Most airplanes rely on each half being exactly the same for balance and straight flight.

Another fairly common paper fold is called a reverse. This happens after a few creases are established in a flat sheet and then reversed to allow a section fold inside another. Usually the inside section will form the plane's tail or rudder.

Another common fold in origami as well as paper airplanes is called water-bomb. It gets its name from the small paper cube based on this fold which will really hold water. After folding a sheet in half, fold both the large diagonals which square the sheet. Turn the sheet over and fold a crease through the center of the "X" made by the two diagonal creases.

Now the sheet makes a complicated move we call the "praying hands" manuever. Both sides come up at the time to form an upright flap. Once in this position, the last step is to squash down the flap using existing creases until the paper is flat again. About half the planes in this program use this fold or a variation so it's important to be able to fold it well.


Paper Airplane Designs:

When you're just starting out with folding paper airplanes, it's a good idea to just follow the steps to the letter. As your skills improve and your confidence grows, you can start being more creative and experiment with new designs of your own.

There are some important things to keep in mind when designing paper airplanes and this article will arm you with information to help you get a headstart in your fun journey.

Paper Airplanes Don't Really Need Tails

Some people think that tails are necessary for paper airplanes to become stable. This is simply not true. Most paper airplane designs do not include tails and even some real airplanes do not have tails. The B-2 Bomber comes to mind.

However, the angle of the tail has a direct effect to the flight of the paper airplane. If you bend the end of the paper airplane's wings up, this would make it fly slower. Bend it down and it'll go faster.

The paper airplane model dubbed as "The Best Paper Airplane In The World" has a tail.

Wide Wings Are Good For Paper Airplanes But . . .

Aviation terminology alert! The width of the wings from tip to tip is called the wingspan. Easy enough? Good. Now the distance between the front of the wings to the back is called the chord. Piece of cake!

Now this is when it gets interesting. The ratio of the wingspan to the average chord is called the aspect ratio. Simply put:

wide wing span + narrow chord = high aspect ratio

. . . and vice versa.

"But why does paper airplanes have low aspect ratio?" You may ask, observant reader. It's because paper isn't the best material for building flying things. A paper airplane with too high an aspect ratio can easily crumple with the force of the launch.

Also, paper airplanes with low aspect ratio are easier to fold than the ones with high aspect ratio.