Basic Kite Parts, Terminology, How it Fly's

The two diagrams above illustrate the common components used in today's kites. The top of the kite is referred to as the "Leading edge", this is the area that the wind flows over to create the kite's lift. There are many different types of Leading edges, some examples include a stiff carbon rod stretched across the top of the kite from wing tip to wing tip or a soft spineless opening used in ram-air foil type kites. The "Right Wing" and "Left Wing" (or sides) are the right and left side of the kite. An increase in pressure on either the right or left wing will cause your kite to turn or change direction. The "Wing Tip" is the furthest edge of the right or left wing. Spars are usually stiff carbon, wood, or fibreglass rods used in the construction of your kite. Most ram-air kites don't use spars at all and rely on the wind and air pockets sewn into the kite to keep the kite's form and allow flight. The "Bridle" is a webbed network of lines that connect to multiple points on the kite and allow the kite to respond or perform to the flyer's commands. Bridles can be as simple as one or two lines connected to a point on the kite or can be as complex as 75-80 different lines connected to multiple points on the kite and joining together at a single or multiple focal points. The bridle of a kite is one of the most important components. A stretched or damaged bridle can greatly effect the performance of your kite and can even keep your kite from flying at all. A change in the length of your bridle as little as a quarter of an inch can greatly effect your kite. Adjustments or repairs should only be done by a qualified person. If you need to replace a line on your bridle, be extra careful to make the length exactly the same as the previous line. The "Connecting Point" is the point that your flying lines will be connected to the bridle of the kite. Many kites will have different connecting points located on the bridle for different flying conditions. One connecting point may be for more power or less wind, another may be for more speed or less wind. The "Lines" are your flying lines that you use to control your kite. On single line kites, you will have one line that you either hold onto or is connected to a spool or winder, on multi line kites, the lines will either connect to a set of straps or handles or a control bar. The "Sail" (not shown) is the material that spans the area of the kite. Sail's come in many different colours and shapes, and can be a variety of different materials. Some of the newer materials used today include rip-stop nylon, Mylar, or Dacron just to mention a few.

What Makes A Kite Fly

There are many factors that go into the design of the kite including weight, aspect ratio, angle of attack, bridle points, line length, and of course, wind speed. Knowing why kites fly and what causes them to do different things will help you in learning to fly. Generally speaking, the larger the kite, the less wind it will take to get it off the ground. This is due to the kite's "Aspect Ratio". Aspect ratio is a calculated figure that compares the sail area of the kite to the weight of the kite. A very large kite that has very little weight will have a higher aspect ratio. But why do they fly in the first place? The basic design of a kite is the same design used in airplane wings. The wind rushes over the top of the wing of an airplane and creates a void or vacuum of air behind the wing. This vacuum creates a low pressure area and the front or bottom of the wing becomes a high pressure area. The wing of the airplane is forced and sucked into the low pressure area, creating lift. Kites fly for the same reason, air rushing over the leading edge of the kite creates a vacuum or low pressure area behind the kite. The kite then tries to move towards the low pressure area and this causes the kite to lift off of the ground. Power or traction kites create a tremendous low pressure area while creating an enormous high pressure area in the front of the kite, usually because of the massive sail area incorporated into the design of power kites. Quad line kites allow the flyer the ability to change the area of the low pressure area by changing the angle of sail of the kite. By rotating the bottom lines of a 4 line kite towards the flyer (pulling on the bottom lines) the low pressure area moves from behind and above the kite to behind and below the kite, causing the kite to slow down or stop it's forward motion and even reverse in flight.

The three diagrams above illustrate the wind path and the low pressure areas created by the wind travelling over the edge of the kite. The 1st diagram shows the wind over a single line kite, this is similar to dual line stunt kites as well. The 2nd diagram shows the low pressure area created by a single skinned power kite, as you can see the greater the sail area of the kite, the greater the pull. The 3rd diagram shows how the low pressure area is created using a ram-air style kite. This design of kite is the closest design to an airplane wing and can generate tremendous amount of pull and virtually creates power as it flies. After this style of kite begins flying, more air passes over the top of the kite. The faster the kite flies, the greater the pull, it virtually creates its own wind once it gets flying, but still requires wind to stay in the air. Ram-air style kites usually have no spines or rigid skeleton and rely on wind trapped inside of cavities sewn inside of the kite to hold their shape. Air flowing into the kite through an opening in the leading edge of the kite will inflate the kite and give the kite its shape. This type of design is great when it comes time to store the kite as it can be folded or rolled up to fit into very small bags. A ram-air style kite when inflated can be larger than a car, but when stored will fit into a small backpack.

Your kite will turn if the low pressure area is increased on only one side of the kite.  Example: By pulling on the left side of your kite, you will cause more air to rush over the edge of the right side increasing the speed of the right side of your kite, the left side will slow down and begin to drop and your kite will begin turning towards the left or counter clockwise. The opposite will happen by pulling on the right side. If your kite constantly tries to turn to one side or the other, your lines may not equal lengths; or on a single line kite, your bridle may not be equal lengths on each side. If your kite tries to dart uncontrollably left or right, you may have too much wind rushing over the bottom or sides of the kite. Changing the angle of attack (the angle that your kite flies as compared to your position) will change the way wind flows over the leading edge, giving your kite more stability (the same effect as tying a long tail to the bottom).

This page only covers some of the basics in kite design and what makes kites perform. An entire encyclopaedia could be written on this subject and we realize that we have left out a lot of information. We don't have the time or space to include "everything" about kite physics in these online manuals and just want to brush over the basics.