Almost every kite design falls into a few main categories.
Single line kites
The simplest possible form of kite just consists of a single sheet of some suitable material, with spars and a bridle to support it. Unfortunately, flat kites are inherently unstable. They can be stabilized by ensuring that most of the drag is generated behind and below the towing point. Several methods may be used singly or in combination:
- Adding a tail
- Adding holes or vents towards the rear of the sail
- Adding a keel
- Simply arranging for a forward towing point.
Tails and vents waste wind energy and so tend to result in a low angle of flight. Vents are rarely used in flat kites. Flat kites generally fly well in light to moderate winds.
Common flat kite designs are: The Classic Diamond, Della Porta, Barn Door, Edo, and Star.
Bowed and Dihedral kites
Flat kites are inherently unstable. This problem can be overcome by making the surface facing the wind slightly convex. Then, if it tips slightly in either direction, one side of the kite is facing the wind flatter, and the other side at a greater angle. This results in more lift on the side flatter to the wind, so restoring the kite to an equilibrium position.
A kite may be made convex to the wind by either of two methods:
* the kite may be bowed, either by a line fixed between the ends of a cross spar and tensioned until a suitable bow is achieved, or simply by wind pressure, or
* the cross spar may be made in two pieces and set at a slight angle, known as a "dihedral", where they join in the middle. Plastic dihedral fittings are widely available for the purpose.
In principle, any kite that is traditionally bowed could also be made as a dihedral, and vice versa, and for this reason we group them together, even though most are traditionally made in one form or the other. But whether, for example, an Eddy kite (originally bowed) is still an Eddy kite if it is built with a dihedral is an esoteric point upon which opinions differ.
Common Bowed kites are: Rokkaku, Eddy, Barn Door, Delta, Genki, Roller, and Fighter.
Cellular (and box) kites
There are many different types of cellular kite with varying characteristics. They range from simple box kites to highly elaborate aerial structures, and even the simplest have an special appeal resulting from their 3-D nature which simpler kites lack.
Common Cellular designs include: Box Kites, Hargrave Box Kite, Conyne, Cody, Snowflake, and Circoflex
Sled kites rely on wind pressure to keep the sail in shape, some not requiring spars at all, making them very cheap, and almost indestructible, except by dragging them through a convenient gorse bush after the wind dropped! They usually fly reliably in a light wind, though a poorly designed sled can deflate if hit by a sudden side wind, falling in a heap to the ground (or a gorse bush).
Common Sled Designs are: Rogallo and the Basc Sled.
Most kites use thin sheet material for their sails. It is well known, however, that this is not the most efficient lifting surface, and aircraft wings invariably have a pear-drop cross section which causes the air passing over the top to travel further than the air passing underneath, so producing a reduction in air pressure above the wing with minimal turbulence. Aircraft use rigid structures but these would be far too heavy to fly as a kite in reasonable wind speeds.
Parafoils include: Flow Forms and many different inflatable designs.
People sometimes ask whether it's possible to make a rotating kite. In fact, there are several types commercially available as well as others that appear at festivals from time to time. For some of these, rotation is an essential part of its means of achieving lift, but for others, it's more incidental.
We've put rotating kites in a single category, but in fact there are three quite distinct types:
* those, like the gyrokite and windmill kite, which rotate about a roughly vertical axis,
* those, like the UFO kite, that rotate about a horizontal axis perpendicular to the wind, and
* those, like the rotating box, which rotate about a roughly horizontal axis in line with the wind.
In the first two types, rotation provides or contributes (if only a little) to the lift, but in the last, it's simply for artistic effect.
Rotating kites: Rotoplane, UFO, and Bols.
Dual line kites
Single line kites, with the exception of fighters, are not usually maneuverable because the only means of control is through the tension of the line.
Dual line kites change all that. If you pull the right line the right half of the sail is pulled towards you and the kite turns to the right, or clockwise, and if you pull the left line the kite goes left, or counterclockwise. Very simple and intuitive. It is also possible to control the speed of the kite, by pulling both lines together - the harder you pull, the faster it goes, and if you allow the lines to go slack by throwing your hands forward, the kite stalls.
There are three widely available types of dual line kite: the Peter Powell diamond stunter, the delta sports kite, and the dual line parafoil.
Triple line kites
In a triple line kite, 2 lines control direction of flight, and the third line allows the angle of attack to be adjusted, so the forward speed can be controlled without walking forwards or backwards to control the joint tension of the lines. Consequently, such a kite can be made to go backwards apart from simply by stalling it. It would be possible to control a triple line kite with your two hands and the third line attached to your belt, but in practice, a triangular or Y-shaped handle is used, allowing it to be controlled with one hand.
Triple line kites are not common and have never really caught on. Nevertheless, there are several that have been discussed on the Internet, and if you want something different, they may well be worth exploring.
Quad line kites
Three line kites allow the sail to be tilted from side to side to control turning, as do two line kites, but they also allow the angle of attack to be controlled, so controlling the speed, and even allowing reverse motion. In addition, four line kites allow the sail to be twisted, causing it to spin like a propeller. Four line kites have caught on far more than three liners and so have benefited from more development and refinement.
Quad line flying is quite different from flying a two line kite. Rather than pulling the lines differentially to perform a turn, they have to be tilted differentially, and rather than pulling them together to control speed, the handles have to be tilted together. Experienced two line fliers normally take a little while to adjust as they have to counter all their acquired habits. Since a quad line kite can be made to go backwards as well as forwards, if it crashes upside down, it can be relaunched as easily as the right way up (provided you can work out which way to turn the handles!) A four line kite can do things no other kite can, and it's an experience not to be missed.
Amongst modern four line kites, two main classes have emerged: the Revolution and its cousins, and four line parafoils.
Common 4 line kites are the Revolution, Decca, and Airbow. There are also many 4 line parafoils used as traction kites.