The Balance between Air and Kite

Thomas Horvath has invented kite flying without wind. His 'active kites' stay in the air, because the pilot is giving the right impulses via the line. And because the kites are precise constructions made of hi-tech material.

As a designer, Horvath is looking for the perfect balance between air and kite.

Something is missing. On a field in Brugg near Zurich stands Thomas Horvath. Cigarette in his mouth, head directed towards the sky. In his hand, he holds a line, which, without tension, climbs into the sky. At the end of the leash, 60 meters above the ground, hangs a big yellow kite. It stays in the air, floating. So far an ordinary scene for a sunny Sunday afternoon.

But something is missing. There is no wind blowing at all. So how can this kite fly?

Horvath started flying kites in the early nineties. Back then high-tech stunt kites with two lines were trendsetting. They depend on the wind in order to be lifted. But wind in Switzerland is seldom constant, even less so in the evening, Horvath's preferred time to fly. Thus the architect and designer had the idea to construct zero-wind kites. That was in the year 2000. He began to design, playfully first, professionally since 2004. That is how he invented zero-wind single-line kites.

By now the term active kites is established. Horvaths inventions fly because the pilot is sending them impulses via the line. When he pulls, the kite is flying towards him gaining height. Then he lets the line loose and – by pulling the line quickly - gives the kite a sharp slap on the nose. It turns around and starts to fly away from the pilot. He then gives more line and lets the kite climb higher with the next pull. Experienced pilots draw flat-spins, float closely above the ground or climb incredible heights – legally 60 meters, potentially several hundred.

1 The designer and his creation: Architect and industrial designer Thomas Horvath examining his model "C'est la vie".
Note: C'est la vie gran turismo in icarex silver.

2 The nose of the kite: A tensioning bungi chord and a shock absorbing rubber cast part.

3 The top side: Here two polyester coated Spectra strings cross each other, the x- and y-lines. They are seven times stronger than steel wire at the same weight.

4 The bottom side: The carbon spreader and the z-line. Beneath the bridle. It's angle defines the attitude of the kite in flight.

5 At the stern of Horvaths active kite the y-line ends. This string adjusts the tension of the whole sail.

6 Spreader and leading edge don't touch each other. They are connected by a line only, following tensegrity principals.

7 Wing-tip: The sail of the kite is made of a polycarbonate coated polyester fabric.

The long way home

Horvaths favorite model is called "Long Way Home": wingspan 272 cm, weight 114 grams. This size-weight-ratio can only be achieved with hi-tech materials. The wings are made of "Icarex", a purpose-built polyester, inherently sturdy and robust. The framework is made of thin carbon tubes, hand-wound and conical. The designer has developed all the details of construction. He tinkers the simplest elements to spare weight and gain steadiness. The whole kite consists of approximately 50 pieces. A core element of the construction is the spreader, a curved carbon tube which goes from one wing rim to the other. Spreader and rim don't touch though, they are connected with a lace. "The idea comes from Buckminster Fuller’s 'tensegrity-principle'", Thomas Horvath explains. "The whole construction is under strain, i.e. 'tension', and all the parts are connected, i.e. 'integrity'". The principle renders the kite elastic and firm at the same time. Much effort went into the profile of the sails. They are waisted like the sails of the superyacht "Alinghi".

"It was possible to calculate the statics of the construction by CAD. The way the sail moves in the air though is not analyzable, even by computer," Horvath emphasizes the complex interaction between kite and wind. In the early stage of the development, he would take the prototypes to the nearest field almost every day. Armed with scissors and adhesives he was adjusting the tension of the sails.

The final fit often was the one contrary to logic

... he remembers. It took him four years to finish the first serial model, in this time he constructed over a hundred prototypes.

Design, in this case, means research. As this kind of kite didn't exist before, Horvath constantly had to invent things, to get to practical solutions. "Everything on the kite is function", he declares proudly. The only aesthetical decision to be taken was choosing colors. But here too, the active kites differ from their dual-line colleagues. They are monochrome white, yellow, orange, green or pink, all matt. Horvath isn’t really aware of the fact that his design is typically Swiss: simple, functional, minimal, accurate. Since he started to sell his models, the construction not only had to be solid but also affordable. Still, the kites aren't cheap. A ready-to-fly specimen costs from 222 to 402 Swiss francs.

Hobby, sport and business

The business slowly starts growing. Most customers are Germans. Horvath delivers to the USA, Portugal and France, too. If business continues like that he will no longer manage to build all the ordered kites by himself although he doesn't really like the idea of employing somebody for certain design steps. "I will definitely go on to build the 'Long Way Home' myself and also carry out its test flight". Nevertheless, he wants to earn a living by designing kites. For now, he still gets half his money out of industrial design. To promote his invention he designed a fascinating website with photographs and videos. The kites campaign best for themselves though, when they magically float in the sky.

This afternoon in Brugg Stefan Furter is present. The young Swiss was European stunt kite champion twice. He too designs his own competition-kites. In order to exercise his sport, he needs wind. To achieve mastery Furter has to conduct the tricks and figures slowly and accurately. That means to fly clean angles or wrap the kite into the lines without losing control. About active kites, he says: "I lack the wind." One-line kites are a good way to practice when no wind is blowing. For designer Horvath he has but respectful admiration. "A freak", he states. As a professional, he is fascinated by the combination of glider and kite, that still can be controlled precisely.

For Horvath, what is going on in the kite scene today all started in the seventies. "The model 'stunter' by Peter Powell is the origin of the whole movement." From there the hi-tech stunt kites were developed in the early nineties. "That was an actual boom back then", he remembers. The boom is over though: "Only the ones who really know how to fly are left today." He hopes that this invention can bring back the rush. Not foremost in Switzerland, where kites have a low significance, but in Germany, the USA or Japan.

One year ago the "Long Way Home" got an agile younger brother: the "Urban Ninja". While the big brother goes for long flights in free nature, "Urban Ninja" likes to dance in the backyard. He doesn’t need a lot of space and manages tricks as the looping, an absolute novelty for a single line kite. "Urban Ninja" is supposed to be the drug leading to further addiction. Horvath has published the design on his website. One can order it as a construction set and assemble it at home. The designer's dream: the brokers on Zurich's "Bahnhofstrasse" practicing their tricks during lunch time.

Glide versus thrust

"Long Way Home" and "Urban Ninja" stand for two extremes in terms of flight characteristics: Glide and thrust. "Long Way Home" is a glider, "Urban Ninja" has thrust. The ability to glide reduces the steering ability, thrust renders agile. Whether a kite goes for one extreme or the other can be adjusted via the bridle. The bridle is the direct prolongation of the line and is attached to the keel spar that connects nose and tail. If the angle of the bridle is flat (light), the kite flies agile - "you grab its nose", Horvath explains. If the angle of the bridle is steep (heavy), however, the kite glides smoothly – "you grab its belt".

Horvath has not only immersed himself in construction and design. Kites go way back into the history of almost every culture. Most sources place their first appearance in China. Long before Christ, they were used there as flying signals. Horvath doesn't like this military origin though. He refers to Polynesia, where kites had a live-saving function even earlier: "The first ones served for fishing: with the offshore wind, a leaf on a line takes the hook out in the sea."

The power of slowdown

How surprising the concept of active kites is, becomes clear, when trying to place them in history. They are a mixture of all elements through times and cultures. Emerged from western stunt kites with their hi-tech materials, they got their way of flying from eastern kite culture: the playful attitude, the line lying on the ground beside the pilot. The "Urban Ninja" is exemplary for the connection of east and west. Form and flight characteristics follow the tradition of fighter kites from India or Pakistan, where one pilot tries to cut the line of the other.

For the inventor active kite flying has nothing to do with sports. Neither with power, an indispensable ingredient for trend sports like kite surfing or snow surfing. "It is all about the aesthetics of the flight", Horvath states, "about deceleration." He wants to conserve what remains of the inexplicable that he experiences while designing his kites. If you observe the man in the field with the line in his hand, while "Long Way Home" is slowly drawing circles high above his head, you can feel the mystery, too: how for heaven's sake is this thing flying? From a certain height on, the line is too long for the pilot to influence the kite. Then it is just floating. "The perfect balance", Thomas Horvath smiles.

This article was first published in the swiss design magazine "hochparterre", Edition 10/07.
The photographs in the article are made by the great Stefan Walter: www.stefanwalter.ch, Zurich Switzerland.