Kites past and present. Research paper on the topic “Kite flying: child’s play or practical aeronautics?” First mention of kites

Kites were invented in China. Later the whole world fell in love with them, but in China there is still a reverent attitude towards kites.
China is believed to be the birthplace of kites. People created them in order to rise into the sky, if not by themselves, then at least through a small aircraft.
Kites eventually conquered the whole world. They are popular not only in China, but also far beyond its borders. Both children and adults enjoy flying bright and light kites into the sky.

History of the kite

Well, a little history from the books so that you don’t have to rummage around for too long).
The earliest kites appeared during the Zhou Dynasty in 770 BC. -256 BC The very first snakes were made from wood. Later, during the Tang Dynasty, kites were made from silk, paper and bamboo. The snake was created as a toy, and the Chinese competed in skill in creating it. It was important not only that the kite fly well, but also be more beautiful than the rest. During the Qing dynasties in the 17th century, kite flying became an art that required a lot of time, money and labor.

Nowadays kites are produced in large quantities, made from lightweight artificial materials and are not expensive.

Flying kites

I don’t know about other countries, but in China, flying kites is a favorite tradition to this day. On warm sunny days in the parks of China you can meet people of absolutely all ages who are passionate about this cute activity. Last spring I tried to fly a kite with my friends, it’s actually very interesting!

In any Chinese city you can often see people flying kites.

By the way, you can buy such a wonderful and original toy as a snake at. Read the store review.

What a selection of these kites are on sale now! You can order them online, or you can buy them in any park. Both small and large, and similar to real birds soaring in the sky and huge bright dragons, and in the form of Peking masks and cartoon characters, there are also small snakes, for example, a bunch of several butterflies for very small children. It’s interesting for me to just walk in the park and watch how passionately people try to launch this structure into the sky, how they catch the wind, hook it, and give it freedom. And having caught the air flow, the snakes rise and hover as bright spots in the sky. There are such interesting kites that buzz and fly very quickly, without stopping, at a level of about 20 meters. They are also on strings.

Already in ancient times, people dreamed of flying into the sky, and the myth of Daedalus and Icarus is a direct confirmation of this. Moreover, even then they understood that they could not do without wings. Well, they could well be replaced by very light and inclined planes of paper and slats relative to the air flow. This is probably how the first kite was born.

In China, this entertainment dates back thousands of years. And later the idea was born to lift a man into the air on a snake. If you believe ancient drawings, the Japanese were quite successful in this centuries ago. Moreover, rising into the sky, tied to kites, they also showered their enemies with arrows.

However, our ancestors also noted no less interesting use of kites. So, in 906, the Kiev prince Oleg used kites during the siege of Constantinople - Constantinople. The chronicle reports that “horses and people made of paper, armed and gilded” appeared above the enemy in the air, that is, they were huge kites made by the Russians. And although they could not cause any harm in principle, they certainly had a moral and psychological impact on the Romans - and a very strong one. After all, people then were very simple and were afraid of everything unusual and incomprehensible.

Subsequently, kites served Russian science well. In particular, it was with the help of a kite that M.V. Lomonosov, starting in 1750, conducted experiments during which he revealed the electrical nature of lightning. Moreover, these experiments in the study of atmospheric electricity were extremely dangerous. So, on June 26, 1753, while flying a kite in a thunderstorm, Lomonosov’s colleague, academician G.V. Richman, died, and despite this, Lomonosov continued his experiments. Snakes at that time were flat and not very stable, although for scientific purposes they were made of considerable size, with an area of several square meters.

At the beginning of the 20th century, kites also contributed to the creation of radio. A. S. Popov used them to raise antennas to a considerable height, which increased the range of receiving and transmitting messages by radio.

At the same time, the talented inventor S.S. Nezhdanovsky was building large kites, which were distinguished by amazing stability and high load-carrying capacity. A student of the famous Russian scientist Nikolai Egorovich Zhukovsky, Professor S.A. Chaplygin later recalled that the snakes were similar in the shape of their wings to later images of tailless airplanes and gliders, but had more vertical planes.

In 1898, the Russian aeronaut S.A. Ulyanin proposed an interesting project for a “kite train” composed of several kites at once to lift observers and scientific equipment into the air. I liked the idea, so even “despite all the inertia of the tsarist autocracy” (as it was customary to write in Soviet times, although in fact this was not always the case) a special “snake team” was formed. Ulyanin and many other observers more than once rose to a height of over 200 meters. It was decided that such “snake trains” could be used on military and scientific vessels, and used for observations and research in the oceans and the Arctic. With their help, it was possible to lift scientific instruments to a height of up to four to five kilometers. And once a kind of kite lifting height record was even set - 9740 meters!

At sea, kites were usually towed by high-speed destroyers, which sailed against the wind, thus forcing them to rise. The cable connecting the kite to the ship was wound onto a winch and either “hauled” (that is, released) or reeled in, and then the kite was lowered to the ship. A photograph from the Niva magazine for 1902 clearly shows how all this was accomplished. An observer from above signaled the manipulations using a flag semaphore, a common means of communication in maritime practice at that time.

It is also important to note the use of kites in the development of the first aircraft. In particular, A.F. Mozhaisky, before starting construction of his aircraft, conducted a series of tests with kites pulled by a team of horses. Based on these experiments, he chose the dimensions of the aircraft and determined the area of its wings, which should provide it with sufficient lifting force.

If we look at photographs of the first airplanes of that time, we will immediately notice how whimsical the imagination of their creators was. There is a disc-shaped wing, “bat wings”, and many wings collected in a package one above the other. A. Mozhaisky's plane was a monoplane, that is, it had only one wing. The Wright brothers' "Flyer" was a biplane and had a pair of wings, but the famous Red Baron von Richthofen flew a triplane during the First World War. And all only because one important rule was always in effect here, derived precisely from the study of kites: the more planes an airplane has, the higher its lifting force.

In 1848, K.I. Konstantinov developed a system for rescuing ships in distress near the shore, on board of which a lifeline was supplied with the help of kites. During the First World War, troops of various countries used kites to raise artillery spotter observers to reconnaissance of enemy positions.

With the development of aeronautics and aircraft, kites began to be used exclusively for entertainment and sporting purposes. It is interesting that before the war, the USSR even held championships of the Soviet Union in kite sports.

Later, water skiing was combined with kite climbing. Currently, this direction has received special development and even its own name - kiting. Today it is a sport in which an athlete moves across the surface of the earth or water using a kite. In this case, the shape of the wings does not matter much - the main thing is that the kite can lift a person into the air!

Municipal government institution, education department of the administration of the urban district of Neftekamsk, Republic of Bashkortostan

Municipal educational budgetary institution

secondary school No. 8

urban district city of Neftekamsk

Republic of Bashkortostan

Historical research work

"Kite:

child's play or practical aeronautics?

Completed by: Vinokurov Anton 7A class

MOBU secondary school No. 8

Head: Nasipova G.U.

Physics teacher.

Neftekamsk, 2014

Content

Introduction …………………………………………………………………… .3-5

History of the kite ………………………………………………. .6-8

Classification (types) of kites ………………………… …9-15

16-19

Conclusion …………………………………………………………………..20

Bibliography …………………………………………………………21

Introduction

From early childhood we know what a kite is: how to fly it and how to control it. We are accustomed to its shape and colorfulness, but have you ever wondered when and why snakes were invented? What were they used for and why do they fly? Did you know that a kite, without exaggeration, can be called the fundamental principle of all flying machines and that the aerodynamics of an airplane wing is based on the aerodynamics of a kite? The main feature of a kite is its simplicity. It is easy to make and use, but what experience does a child gain by playing with a kite! Also, interest in snakes does not decrease with a person’s age. Over the many years since the first kite appeared, they have acquired a new look, and now a new generation of kites has appeared - kites. Kitesurfing and kitesurfing have long been popular among fans of extreme sports.

Kites - this is a whole world with different facets, the world of creativity, the world of science, the world of art. Everyone knows from early childhood what it is

kite: how to fly it and how to control it. Their shape and color are amazing, but have you ever wondered when and why snakes were invented? Having studied the history of kites, we learn that kites were used in scientific research, in meteorology for studying the upper layers of the atmosphere and aerial photography, for dropping loads. Kites play an active role in aircraft modeling, signaling, namely in orienteering, entertainment and sports games.

The German company SkySails has used kites as an additional power source for cargo ships, first testing it in January 2008 on the MS BelugaSkysails. Tests on this 55-meter ship have shown that under favorable conditions, fuel consumption is reduced by 30%.

Without exaggeration, a kite can be called the fundamental principle of all flying machines.

The topic of my work is “Kite flying: children's fun or practical aeronautics?”

What is aeronautics? Aeronautics (aeronautics) is the name of the art of rising into the air with the help of known devices and moving in a certain direction.

The relevance of my chosen topic is obvious. On the one hand, this is children's fun, which requires a lot of imagination and helps broaden one's horizons. On the other hand, designing and flying kites for people who do not view this as an exciting activity makes it possible to understand the basic principles of flight of all aircraft combined. Study the laws of physics and aerodynamics, as well as their practical application.

The first mentions of kites date back to the 2nd century BC, in China (the so-called dragon kite).

For a long time, snakes did not find practical use. From the second half of the 18th century. they are beginning to be widely used in atmospheric scientific research. In 1749, A. Wilson used a kite to measure air temperature at altitude. In 1752, B. Franklin conducted an experiment in which, with the help of a kite, he discovered the electrical nature of lightning and subsequently, thanks to the results obtained, invented a lightning rod. M.V. Lomonosov conducted similar experiments and, independently of Franklin, came to the same results.

Research topic : Kite flying: child's play or practical aeronautics?

Purpose of the study : Identify the factors affecting the launch and flight of a kite.

Object of study : Model of the kite, terrain and weather conditions affecting the flight of the kite.

Subject of study : Qualitative characteristics of kite flight.

Research hypothesis : Using improvised means you can create heavier-than-air aircraft.

Tasks:

Studying the history of kites;

Consideration of types of kites;

Study of the principles of kite flight.

Research methods : work with scientific literature, Internet resources, selection of illustrative material, its design, research, conducting test flights with kite models.

History of the kite

Kites are among the oldest heavier-than-air flying machines invented by humans. It is impossible to say with certainty who and when invented the kite, and when they first took to the air. Ancient Greek sources claim that this happened in the 4th century BC, and that the honor of their invention belongs to Archytas of Tarentum. But one thing is known for certain - in the 4th century BC, kites were widespread in China. It is believed that the first Chinese kites were made of wood. They were built in the shape of fish, birds, beetles, and painted in different colors. The most common figure was that of a serpent - a dragon. This is probably where the name “kite” came from.

They quickly spread throughout East Asia. They began to be used to solve military problems. There is a legend that in 202 BC, General Huang Teng and his army were surrounded by opponents and were in danger of complete destruction. It is said that a random gust of wind blew the general's hat off his head, and then the idea came to him to create a large number of kites equipped with rattles and pipes. The enemy fled in fear from the battlefield amid howls and deafening crashes. The ancient records of the first practical applications of kites are interesting. One of them says that in the 9th century. The Byzantines allegedly lifted a warrior on a kite, who from a height threw incendiary substances into the enemy camp. Also in 559, a man flying a kite was documented in the kingdom of Northern Wei.

In Rus' in 906, Prince Oleg, during the siege of Constantinople, used a kite to intimidate the enemy. And in 1066, William the Conqueror used kites for military signaling during the conquest of England. But, unfortunately, no data has been preserved about the shape of ancient European kites, their structural and flight properties. For a long time, European scientists underestimated the importance of the kite for science. Only from the middle of the 18th century. The kite begins to be used in scientific work. In 1749, A. Wilson (England) used a kite to raise a thermometer to determine the air temperature at altitude. In 1752, physicist W. Franklin used a kite to study lightning. Having discovered the electrical nature of lightning with the help of a kite, Franklin invented the lightning rod.

Kites were used to study atmospheric electricity by the great Russian scientist M.V. Lomonosov and the English physicist I. Newton. In 1804, thanks to a kite, Sir J. Keil was able to formulate the basic laws of aerodynamics. The first manned kite flight took place in 1825. This was done by the English scientist D. Pocock, who lifted his daughter Martha on a snake to a height of several tens of meters. In 1873 A.F. Mozhaisky climbed on a kite towed by three horses. Since 1894, kites have been systematically used to study the upper atmosphere. In 1895, the first snake station was established at the Washington Weather Bureau. In 1896, at the Boston Observatory, a box kite lifting height of 2000 m was reached, and in 1900, the kite was raised there to a height of 4600 m. In 1897, work with kites began in Russia. They were conducted at the Pavlovsk Magnetic Meteorological Observatory, where in 1902 a special snake department was opened.

The kite was widely used in meteorological observatories in Germany, France and Japan. 3may rose to a very great height. For example, at the Linderberg Observatory (Germany) they achieved a kite lift of more than 7000 m. The first radio communication across the Atlantic Ocean was established using a box-shaped kite. The Italian engineer G. Marconi launched a large kite on New Founden Island in 1901, which flew on a wire that served as a receiving antenna. In 1902, successful experiments were carried out on the cruiser “Lieutenant Ilyin” to lift an observer to a height of up to 300 meters using a train of kites. In this case, box-shaped snakes were used, the designs of which were developed by L. Hargrave in 1892. In 1905-1910, the Russian army was armed with a kite of an original design created by Sergei Ulyanin. Entire platoons of snake nauts were part of both ground and naval units, including the Black Sea Fleet. During the First World War, troops of various countries and especially Germany used tethered balloons for observation posts, the lifting height of which, depending on the battle conditions, reached 2000 m. They made it possible to observe the enemy’s position deep in the front and direct artillery fire through telephone communications. When the wind became too strong, box kites were used instead of balloons. Depending on the strength of the wind, a train was made up of 5-10 large box-shaped kites, which were attached to a cable at a certain distance from each other on long wires. A basket for an observer was tied to the cable. In a strong but fairly uniform wind, the observer rose in a basket to a height of up to 800 m. This method of observation had the advantage that it made it possible to get closer to the enemy’s advanced positions. Kites were not as easily shot as hot air balloons, which presented a very large target. In addition, the failure of an individual kite affected the observer's ascent height, but did not cause him to fall.

During the First World War, kites were also used to protect important military installations from attack by enemy aircraft by constructing barriers consisting of small tethered balloons and kites that rose to a height of 3000 m. Wire ropes were lowered from the balloons and kites, which were created for the aircraft the enemy is in great danger.

Nowadays, building a kite is an exciting activity; creating and flying them has not lost and will not lose its importance. The theoretical thought of inventors in many countries gives rise to more and more new designs of kites: flat and box-shaped. Inflatable and rotary. Among the kites you will meet, no two are alike - they all differ from each other in appearance, flight performance or manufacturing technology.

Classification of kites

The classification of kites is not precisely defined. Kites can be big or not very big. There is a very wide variety of kite shapes. Ancient snakes were made using wooden frames and sheets of silk or paper stretched over them. Almost all modern kites are made from carbon fiber plastics and synthetic fabrics.

Flat kites are divided into two types according to their aerodynamic design:

Flat - flat kites. The oldest form of kite flying. And the simplest one. They are figuratively a flat plate of rectangular or any other shape (star, triangle in the form of a projection of a bird, etc.), to which a handrail is tied using a bridle.

Bowed is a category of kites that look very similar to flat kites from the ground. However, this type of kite is a further development of flat kites in terms of stability. To give stability, these snakes have a bend or kink in the longitudinal axis, which, as it were, lifts the ends of the wing and creates a v-shaped wing. This solution provides a significant margin of stability. William Eddy patented this kite design in 1900.

In shape: flat snakes in plan can be made in all sorts of shapes, from square to the artist’s imagination. Let's consider the main ones:

 The rectangular kite is the most common textbook example of a kite, but it is not very stable compared to its larger cousins. The snake has three strips: two of them serve as diagonals (“cross”), and the third is at the top and fastens the diagonals. A strong thread is pulled along the contour of the future kite, connecting all the corners, and a cover made of paper or fabric is glued on. The kite must be equipped with a long and fairly heavy tail to give it stability in flight. Snakes of a similar design were common in Japan; images of dragons were applied to the rectangular canvas.

 Diamond (bowed diamond) –diamond-shapedsnake. The frame is made in the form of intersecting slats. Belongs to the bowed category. There are many schemes for making a kite concave, such as using a central cross where the cross-staffs run at an angle, or stringing a bowstring on a cross-staff, which gives the cross-staff a bow-like bend. With a large v-shape, such a kite does not need a tail, however, with a significant increase in the v-shape, the kite loses lifting force. The bridle is most often tied to the longitudinal rail in two places.

 Delta (delta, bowed delta) is a snake, in plan resembling a delta wing. The frame is somewhat more complicated, since it requires at least three slats, which are rigidly fixed in the form of a triangle (two cantilever and one transverse). The peculiarity of the design is that during flight, wind pressure bends the cantilever slats and the kite takes on a v-shape. The domed structure of the cladding also gives additional stability. Moreover, the stronger the wind blows, the more stable the kite behaves. Models of sports controlled kites received this form. The ability to control is achieved using a two-layer scheme. The pilot holds both rails in his hands. By changing the tension of the rails, controlled flight is achieved.

 Rokkaku - This hexagonal Japanese snake (hence its name) is native to the central Japanese region of Niigata on the coast of the Sea of Japan. It has a central rail and two transverse ones. The transverse slats are given a curved shape (bowed shape), due to this, rokkaku type snakes are very stable even without tails. This is a very common form of kite as it is easy to make.

 Bermuda (Bermuda) - a kite is usually hexagonal in shape, but can have the shape of an octagon and even a more multifaceted figure. The design consists of several flat slats intersecting in the center. A bowstring is stretched along the perimeter of the slats, imparting rigidity to the structure. The sail is already stretched between the slats and the bowstring. Very often, each side of the kite is made of different colors to obtain a more variegated color. Requires a long tail. The snake shares the same name with the island where they were traditionally flown on Easter as a symbol of the ascension of Christ.

Box kites

Box snakes appeared as a result of the development of flat snakes. People have noticed that vertical surfaces greatly affect the stability of a kite's flight. This is how the first box-shaped kite appeared. Box snakes generally do not require a tail.

 The rhombic kite is the simplest box-shaped kite, it is not complicated in design, is stable in flight and is easy to launch. It is based on four

longitudinal slats (spars). Two crosses are inserted between them, each of which consists of two spacer slats. The kite cover is made of two strips of paper or synthetic fabric. This creates two boxes - front and back. This kite design was invented by Australian explorer Lawrence Hargrave in 1893 while trying to build a manned aircraft.

 Potter's is a box-shaped kite that has special flaps to increase lifting force. It consists of four longitudinal slats (spars) and four paired transverse slats-crosses, two boxes and two flaps.

Frameless kites

Frameless snakes are snakes that do not have hard parts. It takes the form of a snake by inflating due to the oncoming air flow. Hence the two advantages of these kites - the probability of breakage when dropped is zero and compactness during transportation. The second advantage allows you to make kites of very large sizes.

 Sled (sleigh) is a kite with a non-rigid frame. In flight, its shell maintains its shape due to the wind, as if inflated. Only two longitudinal slats are used, sewn into the shell, which are not connected to each other. These slats maintain the shape of the shell and prevent it from crumpling. This type of kite behaves quite capriciously in gusty winds. For stable flight, a kite requires a long tail. The advantages of such a kite include ease of manufacture and compactness during transportation, since it can be rolled into a tube without the need for assembly and disassembly.

 Sled foil is a further development of the kite of the previous model. There are no rigid elements in this design at all. The rigidity of the dome is given by cylinders inflated by the oncoming air flow. The pressure created in the cylinders tapering towards the rear edge of the kite is quite enough to keep the canopy straightened in flight. However, a kite of this design also has disadvantages, for example, the dome can easily crumple when the wind subsides and this will lead to the kite falling, even if the wind rises again, the dome can no longer straighten out on its own. It also has certain starting difficulties. But the undeniable advantage of the fact that snakes cannot be broken allowed this design to continue its development.

 Super Sled foil is another development of the “sled”. Three inflatable sections make this kite more resistant to collapse. It also allows you to make this kite of considerable size and obtain significant thrust. Can be used to lift objects, including a camera.

 FlowForm is a very common kite design as it is one of the most stable frameless single line kites. With proper training, in a steady wind it can fly without a tail. However, in strong and gusty winds, the use of the tail is still recommended. They can be made in truly gigantic sizes; an area of 3 sq.m is considered the most common. They are also manufactured with a large number of sections, six, eight and even more.

 The Nasa Para Wing kite is the result of research by the US National Space Agency, which brought to light quite interesting single-layer frameless kites. Developments were carried out in search of optimal systems for launching spacecraft. As a “by-product”, a kite is built by people all over the world. A number of original solutions make this model easy to manufacture. Some models are controllable. Despite many advantages (low material consumption, high thrust, etc.), these kites have a significant drawback - relatively low aerodynamic quality, which, however, is steadily increasing due to further improvement of the kite design.

 Parafoil is a special subclass of frameless kites. This type of kite is made of airtight fabric with closed internal spaces and an air intake facing the oncoming flow. Air, penetrating into the air intake hole, creates excess pressure inside the enclosed space of the kite and inflates the kite like a balloon. However, the design of the kite is such that when inflated, the kite takes on a certain aerodynamic shape, which is capable of creating the lifting force of the kite. There are many types of kites - parafoils: single-line, double-line controlled, four-line controlled. Double-line kites are mainly aerobatic kites, or kites with an area of up to 3 sq.m. Four-line kites are kites with a fairly large area from 4 sq.m., used in sports as a motive force (kiteing). Single-line snakes are for entertainment, come in a variety of designs and shapes, and can even depict all sorts of objects and animals.

 Inflatable - another interesting model is an attempt to combine the advantages of parafoils and frame models. There is also a shell, but now it is inflated not by the wind, but by means of a pump on the ground (like rubber rings). The kite also does not have a frame, but due to excess pressure inside the shell, it already has a flying shape on the ground. Again, by analogy with an inflatable ring - the kite does not sink in the water when it falls, for this reason it is used in kiting when riding on the water surface.

Why do kites fly?

The ability of kites to stay in the air and lift loads is explained by the fact that they have lifting force. Let us give the following experience. If you stick your hand with a plate (a piece of cardboard or plywood) out of the window of a moving bus or carriage, placing it vertically, you will feel that your hand is being carried back with some force. This force arises because a stream of air flows onto the plate and exerts pressure on it. This pressure will be greater if the size of the plate or the speed of movement is increased; At high speed, this force can be so great that sticking your hand out will be dangerous. The force of pressure on the counterflow plate can be reduced many times if the plate is placed with its edge facing the air flow. If the plate is placed at a slight angle, the hand will begin to tilt not only back, but also upward. The angle relative to the air flow is called the angle of attack (usually denoted α - alpha). Snakes fly at an average angle of attack of 10-20°.

So why does a kite fly?

There are four forces acting on a kite: drag, lift, gravity and lift. A B α F 2 F 3 F 1 (see figure).

In a simplified drawing, line AB represents a cross-section of a flat kite. Let's assume that our imaginary kite flies from right to left at an angle α - alpha to the horizon or the oncoming wind flow. Let's consider what forces act on a kite in flight.

A dense mass of air impedes the movement of the kite during takeoff, in other words, it exerts some pressure on it, let's denote it F1. Now let's construct a so-called parallelogram of forces and decompose the force F1 into two components - F2 and F3. The force F2 pushes the kite away from us, which means that as it rises it reduces its initial horizontal speed. Therefore, it is a resistance force. The other force (F3) carries the kite upward, so let’s call it lifting. We have determined that there are two forces acting on the kite: the drag force F2 and the lift force F3.

By lifting the kite into the air (towing it by the rail), we seem to artificially increase the pressure force on the surface of the kite, that is, the force F1. And the faster we run, the more this force increases. But the force F1, as we have determined, is decomposed into two components: F2 and F3. The weight of the kite is constant, but the action of force F2 is prevented by the handrail, the lifting force increases - the kite takes off.

Wind speed increases with height, which is why when launching a kite, they try to raise it to such a height where the wind could support the model at one point. In flight, the kite is always at a certain angle to the direction of the wind.

The drag force is created by the movement of air that flows around the kite.

Lift is the portion of drag that turns into upward force.

The force of attraction is due to the weight of the kite and is applied at a point called the center of gravity.

The driving force is imparted to the kite by a lifeline that acts as a motor. The kite will fly if the lines of action of all these forces intersect at the center of gravity. Otherwise, the kite's flight will be unstable. To meet these requirements, the surface of the kite must be inclined to the wind at the correct angle. The longitudinal stability of the kite is ensured by the tail or the shape of the aerodynamic surface, the transverse stability is ensured by the keel planes installed parallel to the rail, or by the curvature and symmetry of the aerodynamic surface. When making kites, these factors should not be forgotten. The stability of a kite's flight also depends on the position of the kite's center of gravity. The tail shifts the kite's center of gravity down and slows down the kite's oscillations if the wind is gusty or uneven.

Let's calculate the lifting force of a kite using the formula:

Fh=K*S*V*N*cos(a),Where

K=0.096 (coefficient),

S - load-bearing surface (m2),

V - wind speed (m/s),

N - normal pressure coefficient (see table)

Wind speed, V, m/s 1 2 4 6 7 8 9 10 12 15

Normal pressure coefficient N, kg/m2

0,14 0,54 2,17 4,87 6,64 8,67 10,97 13,54 19,5 30,47

a is the angle of inclination.

Example.

Initial data:

S=0.5 m2;

V=6 m/s,

a=45°.

N=4.87 kg/m2. (see table)

Substituting the values into the formula, we get:

Fз=0.096*0.5*6*4.87*0.707=1 kg.

The calculation showed that this kite will rise upward only if its weight does not exceed 1 kg. We calculated the lifting force in the old system of units (kg*s, kilogram-force), and not in the SI system (N, Newton). The fact is that in everyday life it is easier for us to evaluate force in kilograms rather than in newtons, i.e. we know how much effort we need to put in to lift a bag of 5 kg of potatoes. The same is true with kites. To be fair, let’s give the conversion of kilogram-force to the SI system: 1 kg*s = 9.81 N. But not everything is as simple as it looks from the outside. It is very difficult to know the wind speed, even if you fly a kite while holding an anemometer in your hands, the results will not be true. Wind speed changes with height. And the angle of inclination changes slightly during the flight. Only practice will help you fly a kite.

Thus, having considered the basic principles of kite flight, we can safely say that a kite, which is simpler to design and control, is the prototype of more complex aircraft.

Many designers who were previously interested in making kites switched to working on airplanes. But their experience in building kites did not pass without a trace. It certainly played a role in the history of aviation during the first stage of aircraft development.

CONCLUSION

Having considered the history of the kite, having studied the main types and design, and conducting a comparative analysis, I came to the following conclusion.

Nowadays, kite flying, being a child's play, requires a lot of imagination and helps broaden one's horizons. In the process of choosing the type and shape of the kite, design inclinations develop, the designer has the opportunity for artistic expression in the process of inventing emblems and other decorative elements, so the flight of a kite is always an exciting spectacle.

For others it is an exciting sport. Clubs and communities are being created all over the world, uniting kite lovers - both designers and those simply flying them. One of the famous ones is KONE - the Kite Club of New England, part of the Kite Flying Association of America. Some people consider kite flying as a good tradition, for example in Japan.

Abroad, kites are extremely popular among children and youth. They are especially popular in Cuba, Fr. Bali. You can often see how children, even while on the beach, do not part with their favorite pastime - kites of the most varied designs and the brightest colors soar in the air above the sea. Nowadays, the construction of kites can have neither defense nor scientific significance. Since with the development of aviation their role in these areas has decreased.

Designing and flying kites for people who do not view it as entertainment helps to understand the basic principles of flight of all aircraft combined. Kite making has become one of the sections of initial aviation training for schoolchildren, and kites have become full-fledged aircraft along with models of airplanes and gliders, as they allow one to study the laws of physics, aerodynamics and their practical application.

This approach to kites is the initial step for children who plan to connect their lives in the future with the design or operation of aircraft. Without knowledge of calculations, without taking into account the features of the lower layers of the atmosphere, wind direction, etc. do not fly either a kite or a model glider or airplane

Literature

1. Ermakov A.M. The simplest aircraft models: Book. For students 5 - 8 grades. avg. school M.: Education, 1989, - 144 p.

2. Encyclopedia of homemade products. – M.:AST – PRESS, 2002. – 352.: ill. – (Do it yourself).

3. Rozhov V.S. Aircraft modeling circle. For leaders of clubs in schools and out-of-school institutions M.: Prosveshchenie, 1986.-144p.

4. Ermakov A. M. “The simplest aircraft models”, 1989

5. “Optional course in physics” - M: Education, 1998.

6. A.A.Pinsky, V.G.Razumovsky “Physics and Astronomy” - Enlightenment, 1997.

7. Encyclopedia for children. Volume 14. Technology. Ch. ed. M.D. Aksenov. - M.:

Avanta+, 2004.

Internet resources:

1. http://media.aplus.by/page/42/

2. http://sfw.org.ua/index.php?cstart=502&

3.http://www.atrava.ru/08d36bff22e97282f9199fb5069b7547/news/22/news -17903

4. http://www.airwar.ru/other/article/engines.html

5. http://arier.narod.ru/avicos/l-korolev.htm

6. http://www.library.cpilot.info/memo/beregovoy_gt/index.htm

7. http://aviaclub33.ru/?page_id=231

8. http://sitekd.narod.ru/zmey_history.html

9. http://sitekd.narod.ru/zmey_history.html

Kites are among the oldest flying machines. The first documents about them are found several centuries before the start of the new era. Chinese manuscripts say that kites were flown during folk festivals. The Chinese built snakes in the shape of birds, fish, butterflies, beetles, and human figures, which they painted in the brightest colors (Fig. 1).

The most common type of Chinese serpent was the dragon, a fantastic winged serpent. A huge dragon raised into the air was a symbol of supernatural powers. In a number of places in China, until recently, traces of the custom of mass kite flying on the ninth day of the ninth month, Kite Day, remained.

The flying dragon is structurally complex. Two or three dozen light paper cones formed a long round body of a monster, wriggling picturesquely in flight. The serpent-dragon had a large head with a bared mouth. Through the mouth, the wind penetrated into the empty body and, inflating it, supported it in the air. Sometimes, instead of cones, the design of the dragon's frame included gradually smaller round disks, which were connected with each other by cords. Each disc was crossed by a thin bamboo strip, at the end of which large feathers were attached (Fig. 2).

To enhance the effect, special “snake music” was invented, reminiscent of the howling of the wind in a chimney. The device that produced these sounds was made from dry poppy heads into which reed pipes were inserted. A rail was attached to the dragon's mouth, and two long silk ribbons were attached to the tail, which wriggled in the air along with the kite.

An interesting sight was presented by lanterns made from thin colored paper (Fig. 3) and fireworks (Fig. 4) attached to snakes.

Kites became widespread in Korea. At first, their use was purely religious in nature, and then flying kites became a fascinating form of activity and spectacle.

Japanese kite "Kero"

In ancient Japanese drawings you can also find images of kites, which were significantly different in shape from Chinese ones (Fig. 5).

Japanese snakes: a - “butterfly”; b - “Yatsuhana”; c - "Gonbo"; g - from the Nagasaki region; d - "Bozo"; e - "Ato"

A typical Malayan kite (Fig. 6) has the shape of a curvilinear symmetrical triangle. Its frame consists of three intersecting rods, the covering is made of coarse fabric.

European historians attribute the invention of the serpent, regardless of what existed in the countries of the East, to the ancient Greek scientist Archytas of Tarentum (IV century BC).

The ancient records of the first practical applications of kites are interesting. One of them says that in the 9th century. The Byzantines allegedly lifted a warrior on a kite, who from a height threw incendiary substances into the enemy camp. In 906, the Kiev prince Oleg used kites during the capture of Constantinople. The chronicle says that “horses and people made of paper, armed and gilded” appeared in the air above the enemy. And in 1066, William the Conqueror used kites for military signaling during the conquest of England.

But, unfortunately, no data has been preserved about the shape of ancient European kites, their structural and flight properties.

Kite "blinds" design Raqqa

For a long time, European scientists underestimated the importance of the kite for science. Only from the middle of the 18th century. The kite begins to be used in scientific work. In 1749, A. Wilson (England) used a kite to raise a thermometer to determine the air temperature at altitude. In 1752, physicist W. Franklin used a kite to study lightning. Having discovered the electrical nature of lightning with the help of a kite, Franklin invented the lightning rod.

Kites were used to study atmospheric electricity by the great Russian scientist M.V. Lomonosov and the English physicist I. Newton.

The serpent begins to provide valuable services to science. Therefore, it is not surprising that in 1756 the famous mathematician L. Euler wrote the following lines: “A kite, this toy of children, despised by scientists, can, however, make you think deeply about yourself.”

The kite was significantly improved by the Australian scientist L. Hargrave in the 90s. last century. Taking advantage of the work of the first glider pilot, the German engineer O. Lilienthal, Hargrav was the first to use two through boxes connected to each other as a kite. Lilienthal, when designing his gliders, noticed that such devices had good stability in the air. Hargrave patiently searched for the best proportions for his boxes. Eventually, the first box kite appeared, no longer requiring a tail for stability in flight (Fig. 7).

Hargrave's flying boxes were not only a greater impetus for the development of the kite business, but also undoubtedly helped in the design of the first airplanes. This position is confirmed by the similarity with the two-box kite of the biplanes of Voisin, Santos-Duman, Farman and the devices of other early aircraft designers.

The first human ascent on box kites was also accomplished by Hargrave. The passenger was lifted on four kites with a total area of 22 m2.

Frameless "monk"

Since 1894, kites have been systematically used to study the upper atmosphere. In 1895, the first snake station was established at the Washington Weather Bureau. In 1896, at the Boston Observatory, the box kite was raised to a height of 2000 m, and in 1900, the kite was raised to a height of 4600 m.

In 1897, work with kites began in Russia. They were conducted at the Pavlovsk Magnetic Meteorological Observatory, where a special snake department was opened in 1902.

The kite was widely used in meteorological observatories in Germany, France and Japan. The kite (rose to a very high altitude. For example, at the Linderberg Observatory (Germany) they achieved the rise of a kite to more than 7000 m. The first radio communication across the Atlantic Ocean was established using a box-shaped kite. The Italian engineer G. Marconi launched it in 1901. on the island of New Foundlain, a large kite that flew on a wire that served as a receiving antenna.

The British military department became interested in Hargrave's box kite. Lieutenant Cody of the English army modified Hargrave's snakes. He increased its area by adding side wings placed on all corners of the boxes, increased the strength of the structure and introduced a completely new principle for assembling and disassembling the kite. Military observers began to take to the air on such kites.

At the beginning of the 20th century. Cody's work on snakes was continued by the captain of the French army, Sacconey. He created an even more advanced kite design, which is one of the best to this day. Sacconeus, taking advantage of rich subsidies from the military department, had the opportunity to carry out his experiments on a wide scale. He thoroughly developed the principle of towing kites: one group of kites lifted the main rail (cable) into the air, the other towed the load along the cable. Sacconei set the first records for the height and carrying capacity of kites.

The works of Sacconaeus found their successors in many armies of Europe. In Russia, Colonel Ulyanin created a special kite for the army (Fig. 8 and 9). A valuable and ingenious innovation in the kites of his design were articulated wings, which automatically increased the area of the kite when the wind weakened. In addition to Ulyanin, Kuznetsov, Prakhov and others were fond of snakes, and they created successful designs. During the Russo-Japanese War of 1904-1905. in the Russian army there were special snake units.

In parallel with Cody’s work in Europe, mainly in France, other designers also carried out their experiments. Of these, we should mention Plotter, who changed the place of attachment of the bridle and created kites with keel planes that increased the carrying capacity.

An interesting design of the original single-box kite was proposed by the French engineer Lecornu. He created a snake whose box resembles a honeycomb (Fig. 10). Lecornu justified the idea of building his kite by observing the flight of birds. If you look at a flying bird, you will notice that the planes of the body and wings form a certain angle. Lecornu made the same installation angle of 30° at the horizontal planes of the kite.

During the First World War, troops from various countries, and especially Germany, used tethered balloons for observation posts, the lifting height of which, depending on the battle conditions, reached 2000 m. They made it possible to observe the location of the enemy deep in the front and direct artillery fire through telephone communications. When the wind became too strong, box kites were used instead of balloons. Depending on the strength of the wind, a train was made up of 5-10 large box-shaped kites, which were attached to a cable at a certain distance from each other on long wires. A basket for an observer was tied to the cable. In a strong but fairly uniform wind, the observer rose in the basket to a height of up to 800 m.

This method of observation had the advantage that it made it possible to get closer to the enemy's forward positions. Kites were not as easily shot as hot air balloons, which presented a very large target. In addition, the failure of an individual kite affected the observer's ascent height, but did not cause him to fall. A single incendiary rocket hitting the ball was enough to kill it, since it was filled with flammable hydrogen.

Monoblock kite designed by Roche-Donzel

For the snake barriers of hangars near Brussels, large snakes were made in the form of tethered aircraft. The snakes copied the outlines of aircraft of various designs (monoplanes, biplanes) in order to mislead enemy pilots.

In the spring of 1915, an interesting incident occurred in Germany when a tethered aircraft misled not enemy pilots, but its own anti-aircraft battery. One day, early in the morning, a tethered biplane was lifted into the air. Soon after rising, he disappeared into the clouds. When the clouds cleared towards noon, this plane suddenly appeared in their gap. German observers had the impression that the clouds were motionless and that the biplane was flying at fairly high speed. Soon he disappeared into a cloud, only to reappear immediately in the next gap. Air surveillance and communications posts reported: “Enemy aircraft.” Anti-aircraft batteries opened barrage fire. Guns thundered around the airfield, trying to destroy the air enemy. The plane disappeared into the clouds, then reappeared, and the barrage continued until the Germans finally realized that they had fired at their own tethered plane. The latter was not shot down only because when firing an adjustment was made for the imaginary speed of the aircraft and the shells invariably ended up ahead of the stationary target.

Kite making in Europe reached its peak towards the end of the war, in 1918. After this, interest in kites waned. The rapid development of aviation began to displace snakes from military affairs.

Kite "star" designed by Babyuk

In the Soviet Union, the hobby for kites began almost simultaneously with aircraft modeling. Already at the first all-Union flying model competitions in 1926, fairly well-flying box kites built by Kyiv aircraft modelers under the leadership of I. Babyuk were presented. Eleven canvas kites with a total working area of 42.5 m2 were launched on a 3 mm thick steel cable from a special balloon winch. The design of these kites is a modified classic Sacconeus type.

The number of box kite trains submitted to all-Union aircraft modeling competitions increased. Eight trains took part in the 1935 competition. Then, for the first time, the various uses of kites were most fully demonstrated. “Air mailmen” ran up and down the railing, with the help of which “paratrooper” dolls jumped, “bombs” and leaflets were dropped, and a smoke screen was demonstrated. The “parachutist” dolls made long jumps following the dropped live “landing party” - white mice in a cage. Dropping model gliders from kites has become commonplace. From a high-altitude launch, many glider models flew several kilometers away.

In pioneer camps, kites were increasingly used for signaling during war games. It was not uncommon in winter to see a skier, towed by a kite, easily gliding across the snow.

Kite making became one of the sections of the initial aviation training of pioneers and schoolchildren, and kites became full-fledged aircraft along with models of airplanes and gliders.

At the Serpukhov House of Pioneers in 1931, a children's snake station was created and successfully operated. The leaders of this station were annually invited with their kite team to the All-Union aircraft modeling competitions.

Soon the experience of the Serpukhovites became widely known. All-Union competitions began to be held independently every year. The snake stations of Saratov, Kyiv, Tula, Stalingrad and other cities represented their teams at the competition.

The leaders of children's kite stations and young "snake riders" with great enthusiasm designed kites and launched them, and carried out work among pioneers and schoolchildren.

In 1937, in Zvenigorod, the Central Council of Osoaviakhim of the USSR organized the First All-Union Box Kite Competition. Unfavorable meteorological conditions (lack of the necessary wind) did not make it possible to achieve record-breaking kite flights. But still, although at a low altitude, it was possible to test their design features.

In 1938, in the village of Shcherbinka (now a city in the Moscow region), the Second All-Union Box Kite Competition was held, at which designs of exceptional interest were shown. For example, the Serpukhov children's kite station presented kites of a modified "Grund" design with a load-bearing area of 20 m 2. The kite lifted a load weighing up to 60 kg. A kite parachute, a kite glider and others were shown.

At the III All-Union Box Kite Competition, which took place in 1939 in Serpukhov, records were set for kite flight to altitude. A single kite, designed by the Kiev aircraft modeller (that’s what the creators of kites came to be called) Gromov, was raised to a height of 1550 m. A train, made up of box-shaped kites designed by the Saratov aircraft modeller Grigorenko, was raised to a height of 1800 m. During the Great Patriotic War (1943 .) A. Grigorenko was awarded for the combat use of box kites.

At the IV All-Union competitions, the technical requirements for the design of kites were clearly defined. For example, each kite had to be kept in the air at a wind speed of no more than 4-5 m/s at the ground, the load-bearing area of each kite should be at least 5 m 2, the total area of the kite train should be such that with a wind of no more than 7 m/s it was possible to lift a load weighing at least 80 kg. The number of kites should be no more than 10 pieces. The head snake could have a large area, the configuration and color of the kites was arbitrary.

On each snake train it was asked to install various devices and mechanisms, for example, “air mailmen” capable of lifting a load weighing up to 2 kg, locks for composing a snake train (with a rail diameter of at least 3 mm), devices for aerial photography and others.

According to the terms of the competition, each team had to present a game scenario, during which they were supposed to launch a snake train. The scenario could include, for example, bombing, i.e. dropping “bombs” on some previously planned target, an “airborne assault” (dropping dolls), ski racing, transporting a wounded person on a sleigh pulled by a kite, sound, light and other types of alarms from the kite, dropping reports and leaflets.

Competitions were held for the flight altitude of a single kite, the launch height of a kite train, the maximum load capacity of a kite train, and the speed of assembling and launching a single kite.

To ensure success in competitions, many groups of circles made various auxiliary means. For example, in the Serpukhov House of Pioneers, model airplane schoolchildren made a dynamometer to test the strength of a handrail. A dynamometer mounted on the snake turned on a red light at critical voltage. The same team made an anemometer from an old alarm clock, and with the help of this device changes in wind strength were recorded.

Schoolchildren installed a barograph on the snake, a device for dropping a single “parachutist” or ground “landing” doll to a given point.

Young aircraft modelers at the Kolomna Station for Young Technicians (Moscow region) built box-shaped kites with wing flaps, which provided the kite with greater stability at an angle of about 50°. Aircraft modelers at the Voronezh Young Technicians Station built profiled box kites.

Saratov aircraft modelers brought a kite train of five box-shaped kites to the competition. Each snake weighs up to 9 kg. The head snake had a total area of 17 m2. There was a camera installed on the snake train that took 12 photographs. The train was capable of towing one skier.

A team of Kyiv aircraft modelers brought a kite train of six kites to the competition. It was possible to drop a large “parachutist” doll from it (up to 70 cm, while the parachute dome was 4 m in diameter).

Young aircraft modelers worked hard, preparing for new starts. In Leningrad, more than 150 participants took part in the city kite competition in the spring of 1941.

After the Great Patriotic War, competitions were not held.

Nowadays, the construction of kites can have neither defense nor scientific significance. However, as a simple, very accessible and exciting activity, creating and flying kites has not lost and will not lose its importance.

Abroad, especially in socialist countries, kites are extremely popular among children and youth. They are especially popular in Cuba. You can often see how Cuban children, even while on the beach, do not part with their favorite pastime - kites of the most varied designs and the brightest colors hover in the air above the sea.

History of kites

Kites are among the oldest flying machines. The first documents about them are found several centuries before the start of the new chronology. Chinese manuscripts say that kites are in the shape of birds, fish, butterflies, beetles, and human figures, which were painted in the brightest colors.

The most common type of Chinese kite was the Dragon- a fantastic winged serpent. A huge dragon raised into the air was a symbol of supernatural powers. In a number of places in China, until recently, traces of the custom of mass kite flying on the ninth day of the ninth month were preserved - snake day.

An interesting sight was presented by lanterns made from thin colored paper and fireworks attached to snakes.

Kites became widespread in Korea. At first, their use was purely religious in nature, and then flying kites became a fascinating form of activity and spectacle.

In ancient Japanese drawings you can also find images of kites, which were significantly different in shape from Chinese ones.

A typical Malayan kite has the shape of a curvilinear, symmetrical triangle. Its frame consists of three intersecting rods, the covering is made of coarse fabric.

European historians attribute the invention of the serpent, regardless of what existed in the countries of the East, to the ancient Greek scientist Archytas of Tarentum (IV century BC).

Interesting are the ancient records about the first practical applications of kites; one of them says that in the 9th century. The Byzantines allegedly lifted a warrior on a kite, who from a height threw incendiary substances into the enemy camp. In 906, the Kiev prince Oleg used kites during the capture of Constantinople. The chronicle says that “horses and people made of paper, armed and gilded” appeared in the air above the enemy. And in 1066, William the Conqueror used kites for military signaling during the conquest of England.

But, unfortunately, no data has been preserved about the shape of ancient European kites, their structural and flight properties.

For a long time, European scientists underestimated the importance of the kite for science. Only from the middle of the 18th century. the kite begins to be used during work. In 1749, A. Wilson (England) used a kite to raise a thermometer to determine the air temperature at altitude. In 1752, physicist W. Franklin used a kite to study lightning. Having discovered the electrical nature of lightning with the help of a kite, Franklin invented the lightning rod.

Kites were used to study atmospheric electricity by the great Russian scientist M.V. Lomonosov and the English physicist I. Newton.

By launching kites into the air, M.V. Lomonosov studied the upper layers of the atmosphere and the nature of lightning. On June 26, 1753, Lomonosov “with the help of a kite extracted lightning from the clouds.” He flew a kite into a thunderstorm and released a discharge of static electricity along its string, used as a conductor. These experiments almost cost him his life - Lomonosov accidentally left the room shortly before a strong electrical discharge, and Academician Richman, who was there, died.

The serpent begins to provide valuable services to science. Therefore, it is not surprising that in 1756 the famous mathematician L. Euler wrote the following lines: “The kite, this toy for children, despised by scientists, can, however, make you think deeply about yourself.”

Since 1848, a lot of work on raising kites was carried out by the commander of the Okhten pyrotechnic school K.I. Konstantinov. He developed a system for rescuing ships that suffered accidents near the shore: first a thin cord was supplied to the ship using kites, and then a strong rope.

The kite was significantly improved by the Australian scientist L. Hargrave in the 90s. XIX century. Taking advantage of the work of the first glider pilot, the German engineer O. Lilienthal, Hargrav was the first to use two through boxes connected to each other as a kite. Lilienthal, when designing his gliders, noticed that such devices had good stability in the air. Hargrave patiently searched for the best proportions for his boxes. Eventually the first box kite appeared, no longer requiring a tail for stability in flight.

Hargrave's flying boxes were not only a great impetus for the development of the kite business, but also undoubtedly helped in the design of the first airplanes. This position is confirmed by the similarity with the two-box kite of the biplanes of Voisin, Santos-Dumont, Farman and the devices of other early aircraft designers.

The first human ascent on box kites was also accomplished by Hargrave. The passenger was lifted on four kites with a total area of 22 m2.

In 1897, work with kites began in Russia. They were conducted at the Pavlovsk Magnetic Meteorological Observatory, where a special snake department was opened in 1902.

The works of Russian scientists - Chairman of the Russian Technical Society M.M. - date back to the 90s of the 19th century. Pomortsev and academician M.A. Rykachev on the use of kites in the field of meteorology. Pomortsev created a number of original kites for these purposes, and Rykachev designed special devices. Beginning in 1894, kites were systematically used to study the upper atmosphere.

At the threshold of the 20th century, kites helped the inventor of radio A.S. Popov in improving wireless telegraph communication - an antenna was lifted into the air on kites.

The first radio communication across the Atlantic Ocean was made using a box kite. The Italian engineer G. Marconi launched a large kite on the island of New Foundlain in 1901, which flew on a wire that served as a receiving antenna.

Not only scientists were involved in the issues of kite flight; military departments were also interested in them. So, in 1899, during maneuvers in the Kyiv Military District, a group of soldiers lifted into the air with the help of a winch a train of several box-shaped kites with a cabin for an observer. The box-shaped kites were built according to the design of Captain S.A. Ulyanin.

The works of Sacconaeus found their successors in many armies of Europe. In Russia, Colonel Ulyanin created a special kite for the army. A valuable and ingenious innovation in the kites of his design were articulated wings, which automatically increased the area of the kite when the wind weakened. In addition to Ulyanin, Kuznetsov, Prakhov and others were fond of snakes, and they created successful designs. During the Russo-Japanese War of 1904-1905. in the Russian army there were special snake units.

In parallel with Cody’s work in Europe, mainly in France, other designers also carried out their experiments. Of these, we should mention Potter, who changed the location of the bridle attachment and created kites with keel planes that increased the carrying capacity.

An interesting design of the original single-box kite was proposed by the French engineer Lecornu. He created a snake whose box resembles a honeycomb. Lecornu justified the idea of building his kite by observing the flight of birds. If you look at a flying bird, you will notice that the planes of the body and wings form a certain angle. Lecornu made the same installation angle of 30 degrees at the horizontal planes of the kite.

In the spring of 1915, an interesting incident occurred in Germany when a tethered aircraft misled not enemy pilots, but its own anti-aircraft battery. One day, early in the morning, a tethered biplane was lifted into the air. Soon after rising, he disappeared into the clouds. When the clouds cleared towards noon, this plane suddenly appeared in their gap. German observers had the impression that the clouds were motionless and that the biplane was flying at fairly high speed. Soon he disappeared into a cloud, only to reappear immediately in the next gap. Air surveillance and communications posts reported: “Enemy aircraft.” Anti-aircraft batteries opened barrage fire. Guns thundered around the airfield, trying to destroy the air enemy. The plane disappeared into the clouds, then reappeared, and the barrage continued until the Germans finally realized that they had fired at their own tethered plane. The latter was not shot down only because when firing, an adjustment was made for the imaginary speed of the aircraft and the shells invariably ended up ahead of the stationary target.

Kite making in Europe reached its peak towards the end of the war, in 1918. After this, interest in kites waned. The rapid development of aviation began to displace snakes from military affairs.

In the Soviet Union, the hobby for kites began almost simultaneously with aircraft modeling. Already at the first all-Union competitions of flying models in 1926, quite well-flying box-shaped kites were presented, built by Kyiv aircraft modelers under the leadership of I. Babyuk. Eleven canvas kites with a total working area of 42.5 m2 were launched on a 3 mm thick steel cable from a special balloon winch. The design of these kites is a modified classic Sacconeus type.

The number of box kite trains submitted to all-Union aircraft modeling competitions increased. Eight trains took part in the 1935 competition. Then, for the first time, the various uses of kites were most fully demonstrated. “Air mailmen” ran up and down the railing, with the help of which “parachutist” dolls jumped, “bombs” and leaflets were dropped, and a smoke screen was demonstrated. The “parachutist” dolls made long jumps following the dropped live “landing force” - white mice in a cage. Dropping model gliders from kites has become commonplace. From a high-altitude launch, many glider models flew several kilometers away.

In pioneer camps, kites were increasingly used for signaling during war games. It was not uncommon in winter to see a skier, towed by a kite, easily gliding across the snow.

Kite making became one of the sections of the initial aviation training of pioneers and schoolchildren, and kites became full-fledged aircraft along with models of airplanes and gliders.

The leaders of children's kite stations and young “snake riders” with great enthusiasm designed kites and launched them, and carried out work among pioneers and schoolchildren.

In 1937, the Central Council of Osoaviakhim of the USSR organized the First All-Union Box Kite Competition in Zvenigorod. Unfavorable meteorological conditions (lack of the necessary wind) did not make it possible to achieve record-breaking kite flights. But still, although at a low altitude, it was possible to test their design features.

In 1938, in the village of Shcherbinka (now a city in the Moscow region), the Second All-Union Box Kite Competition was held, at which designs of exceptional interest were shown. For example, the Serpukhov children's kite station presented kites of a modified "Grund" design with a load-bearing area of 20 m2. The kite lifted a load weighing up to 60 kg. A kite parachute, a kite glider and others were shown.

On each snake train it was possible to install various devices and mechanisms, for example, “air mailmen” capable of lifting a load weighing up to 2 kg, locks for composing a snake train (with a rail diameter of at least 3 mm), devices for aerial photography and others.

According to the terms of the competition, each team had to present a game scenario, during which they were supposed to launch a snake train. The scenario could include, for example, a bombing, i.e. dropping “bombs” on some previously planned target, an “airborne assault” (dropping dolls), a ski race, transporting a wounded person on a sleigh pulled by a kite, sound, light and other types of alarms from the kite, dropping reports and leaflets.

Competitions were held for the flight altitude of a single kite, the launch height of a kite train, the maximum load capacity of a kite train, and the speed of assembling and launching a single kite.

To ensure success in competitions, many groups of circles made various auxiliary means. For example, in the Serpukhov House of Pioneers, model airplane schoolchildren made a dynamometer to test the strength of a handrail. A dynamometer mounted on the snake turned on a red light at critical voltage. In the same team, an anemometer was made from an old alarm clock, and with the help of this device the change in the strength of the meter was recorded.

Schoolchildren installed a barograph on the snake, a device for dropping a single “parachutist” doll or a group “landing force” to a given point.

Young aircraft modelers at the Kolomna Station for Young Technicians (Moscow region) built box-shaped kites with wing flaps, which provided the kite with greater stability at an angle of about 50 degrees. Aircraft modelers at the Voronezh Young Technicians Station built profiled box kites.

Saratov aircraft modelers brought to the competition a kite train of five box-shaped kites, each kite weighing up to 9 kg. The head snake had a total area of 17 m2. There was a camera installed on the snake train that took 12 photographs. The train was capable of towing one skier.

After World War II, interest in kites moved into a new direction - the development and use of its aerobatic properties.

In 1949, Francis Rogallo invents the flexible wing.

And in 1964, Domino Jalbert began to use a parafoil type wing, which contributed to the development of such modern aircraft as the paraglider and sports parachute.

With the advent of Peter Powell's two-line aerobatic kite in 1972, interest in sport piloting increased sharply.

In the 70s, several Englishmen used round kite parachutes to create the necessary traction force on water skis. In 1977, the Dutchman Gisbertus Panhuis received a patent. The athlete stood on a board, which was driven by a parachute kite.

The Swiss Ren Kugn sailed in the mid-80s on a structure similar to a wakeboard, using a paraglider to create thrust. He was probably the first athlete to make a high jump in a light wind.

In the 80s, the founder of the kite buggy sport, Peter Lynn from New Zealand, created a buggy design made of stainless steel. Kite buggy is a special three-wheeled cart for riding behind a kite.

And finally, in 1984, the Frenchmen Dominique and Bruno Leganu, who were involved in windsurfing and surfing, received a patent for a “sea wing” that could be easily relaunched from the surface of the water. The Leganu brothers devoted themselves entirely to the development of kitesurfing, starting in the early 1980s. A design feature of their kite was the front inflatable balloon, which made it quite easy to lift the kite if it fell on the water.