Preface Contessa Caproni Presentation Marco Majrani

Give the ones you love wings to fly, roots to come back, and reasons to stay. Give those you love wings to fly, roots to return and reasons to stay. (Dalai Lama)

Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return.

Once you learn to fly, you will walk the earth looking at the sky because that is where you have been and that is where you will want to return.

(Leonardo da Vinci)

Flying has always been one of man's greatest desires. Since he was a child he has looked at the sky and dreamed of having wings to be able to leave the ground and fly freely. The hot air balloon as a magical and ancient object is above all a metaphor for freedom of the soul. In order to fly it needs to leave the weights and ballasts that keep it still, anchored to the earth's ground, a little heat and a good friendly wind to direct it.

A hot air balloon is an aerial vehicle belonging to the aerostat category that uses hot air to obtain the upward thrust necessary to get off the ground according to Archimedes' principle. The first hot air balloons date back to 220 AD. in China where they were used for military signaling but were small in size and did not carry passengers.

1500 years later the first documented flight of a hot air balloon took place by the Portuguese Bartolomeu de Guismao who in 1709 managed to make a paper balloon full of hot air take off for a few meters, surprising the court of King Joao V We have to wait a few more decades, on October 19, 1783, when the Montgolfier brothers were inspired by the volatile residues of paper burned in the fireplace which contravened the gravitational laws. They created a balloon that used hot air to float in the air. Sons of a rich paper merchant they had the tools to pursue the dream of flying but few know that the two brothers made a pact with their father that prevented them from getting on board, under penalty of suspension of the lavish financing.

It was only on 5 June 1783 in Annonay that the first real hot air balloon flight in history took place. On board a goose, a rooster and a sheep. On 19 September 1783 Jaques-Etienne Montgolfier decided to demonstrate his invention in Paris at the court of Louis XVI and Marie Antoinette to whom the event was dedicated. Present among the astonished public were the scientist Pilatre de Rozier and the Marquis D'Arlandes who decided to challenge fate in the name of science and about two months later they were the first to board the flying balloon.

The resonance of the Montgolfier brothers' undertaking was great and led to other attempts around the world. On 13 March 1784 Paolo Andreani made his very Italian flight with two farmers who made history on board: Giuseppe Rossi and Gaetano Barzago, appropriately made bold by the wine offered to them before the adventure.

Always Italian, the new challenge of the Tuscan Andrea Lunardi who built the first gas balloon. This hot air balloon, which had greater stability and autonomy, was proposed to the court of London on 15 September 1784. The flight lasted 2 hours and 15 minutes. Modern hot air balloons with a hot air source on board were created by Ed Yost in the 1950s. His first flight was documented on October 22, 1960. </ P>

The passion for flying continues without ever running out and hot air balloons continue to make people dream and attract the attention of anyone who sees them pass by.

HOT AIR BALLOON - TECHNIQUE AND AEROSTATIC:

The operating principle of a modern hot air balloon is absolutely identical to that of the Montgolfier brothers' balloon from the end of the 18th century, already intuited by the Italian Jesuit Francesco Lana in 1670: the same principle that allows ships to float. The differences lie only in the materials used for construction and in the system adopted to heat the air: today, instead of a brazier in which straw and wool burn, sophisticated propane burners are used, the result of careful technological research.

Today as then, therefore, a hot air balloon flies carried by the wind and the pilot is not able to establish exactly where he will land. However, the pilot can control the flight altitude with great precision: by following the currents at the various altitudes he can therefore, within certain limits and with great approximation, predict the route but nothing is ever established with precision, the conditions can change rapidly so much so that two balloons that fly close together can take different directions despite being at the same altitude and on the same route.

A hot air balloon essentially consists of three parts: casing, burner and nacelle.

The casing must contain the air heated by the burner. The structure ure is made up of nylon panels sewn onto vertical and horizontal ribbons. At the top of the balloon, the vertical ribbons are gathered in a "crowning ring" while at the base they are extended by steel cables which in turn are then fixed to the "load panel" on which the burner is mounted. The top of the casing is open and is closed from the inside by means of a circular panel of a larger diameter than that of the opening. By means of the pressure exerted by the hot air, the panel is held in position thus preventing the hot air from escaping (special "Velcro" tapes facilitate the seal and prevent accidental or unwanted openings). By means of a system of tie rods it is possible to open the panel to accelerate the descent in flight or to facilitate deflation of the balloon after landing. Given its shape, it is called a "parachute valve" or even just a "parachute" even if this is obviously not its function.

The purpose of the burner, as we have seen, is to heat the air inside the casing. The burner, generally double or quadruple in the larger balloons, is fixed to the "load panel" by means of a cardan joint which allows the flame to be directed precisely inside the casing. The burner is powered by liquid propane gas contained in special steel or aluminum tanks housed inside the basket. By opening the taps, the propane reaches a coil through flexible pipes where, under the effect of the heat, the liquid returns to its gaseous state, mixes with the air and is set on fire from time to time by a pilot flame fed by the same cylinders. The gas delivery to the burner and therefore the flames are regulated by the pilot using special throttle valves.

GENERAL INFORMATION

AEROSTATIC FLIGHT: PRINCIPLES

Aerostatic flight is based on Archimedes' principle according to which "A body immersed in a fluid receives an upward thrust equal to the weight of the displaced fluid". A balloon filled with air that is hotter than the external one therefore receives an upward thrust equal to the weight of a quantity of atmospheric air equal to its volume. If this thrust is greater than the weight of the aerostat, it detaches from the ground and flies. It will continue its ascent until an equilibrium is reached between aerostatic thrust and density of the surrounding atmosphere. To resume the vertical movement of ascension it will therefore be necessary to introduce new hot air and break the balance. To reverse the thrust and decrease the altitude, a decrease in the temperature of the air contained in the balloon will therefore be necessary. The fundamental difference between a hot air balloon (balloon) and a gas balloon is given by the system used to vary the altitude. While in the hot air balloon the variation is obtained by heating and letting the air inside the envelope cool, the gas balloon rises by getting rid of the sand contained in special bags that act as ballast and descends by dispersing gas by means of a valve.</p >

THE BALLOON

The principle that allows modern hot air balloons to fly has not changed compared to the one devised by the Mongolfieres brothers in the 18th century. The differences are given by the safer and more performing materials and by the system adopted to heat the air. Gas burners replaced braziers with straw and wool. Even today the hot air balloon flies carried by the wind and the pilot listens attentively to every climatic and current variation without being able to completely control its progress and its landing but can control its altitude with moderate precision. The hot air balloon consists of three main parts: the casing (balloon), the spacecraft (basket) and the burner. The casing contains the hot air produced by the burners and is made up of nylon panels sewn onto vertical and horizontal tapes gathered in a crowning ring at the top. At the base they are then inserted into steel cables fixed to the load panel on which the burner is mounted. Through a system of tie rods it is possible to open a panel, called a parachute, to accelerate the descent or to facilitate the deflation of the balloon once it has landed.

The burner can be double or quadruple according to the size of the balloon and the volume of hot air it will have to produce to allow for the correct aerostatic balance. It is fixed to the loading panel via a joint which allows the flame to be directed inside the casing with precision, avoiding damage and burns. It is powered by liquid propane gas contained in special steel cylinders anchored inside the basket from which flexible pipes supply the burners and allow the pilot to control the flow by means of throttle valves. The carrycot, which varies in size, is made of woven wicker that still offers extreme strength, lightness and elasticity as well as the charm of an ancient structure. It has a supporting structure of metal tubes covered with soft material which makes it comfortable and safe. The cylinders are housed in the corners of the basket and the on-board instruments are also placed. The volume of a medium-sized hot air balloon, capable of carrying three or four people, varies between 2000 and 3000 cubic meters of capacity. The considerable inertia of a medium-sized balloon makes the skill and preparation of the pilot essential, who governs its mass by anticipating its ascent and descent reactions. The flight autonomy depends on the propane available to the burners, on the weight carried and obviously on the weather conditions.

During the preparation for flight, the balloon is removed from its container, "unrolled" and well laid out along the terrain chosen for take-off and anchored to the basket. At this point the pilot introduces cold air for the first inflation by means of a dimensioned fan while the support crew helps the balloon in its filling. Once the balloon is sufficiently inflated, the burners will be activated which, by introducing hot air, will allow it to be lifted from the ground. The balloon remains anchored to the ground until the moment of maximum lift when the passengers will be invited to get on the spacecraft. The balloon is ready to take off!

The essential on-board instrumentation for flight is the altimeter which measures and indicates the flight altitude of the balloon, detecting the variation in atmospheric pressure with respect to the height above sea level. Since the atmospheric pressure is influenced by the weather conditions, it is necessary to calibrate the altimeter with a certain frequency. The pilot enters the altitude of the take-off point and checks the rules governing the airspace.

The variometer is another indispensable tool for flying and measures and indicates the vertical speed of the ball expressed in feet per minute or meters per second.

GPS is another useful flying tool that is now in common use. Thanks to the data received at the satellite level, it indicates your position, speed, altitude and direction. It is possible to check one's real route compared to the established one and calculate the travel times and arrival time. Indispensable tool in situations where the pilot needs to know the exact position and cruising speed such as flights at high altitudes, mountains, above the clouds and in competition.

On board the balloon, the pilot also makes use of two-way radio equipment. The first has an aeronautical VHF radio which allows you to maintain contact with the bodies responsible for air traffic control. The second radio allows you to communicate with your ground crew and with the other balloons.

Finally, the thermal probe necessary for measuring the internal temperature of the casing, which allows the pilot to verify and not exceed the maximum temperatures established by the manufacturer.

THE GAS BALLOON

Gas balloons are now the prerogative of a small number of enthusiasts who continue a chapter in the history of "lighter-than-air" flight, mostly expressed throughout the 19th century and the first half of the 20th century. The very high operating costs due to the material used for its inflation do not favor its diffusion and the balloons, compared to hot air balloons, are only a few thousand all over the world. However, the oldest aerostat flight competition is disputed with gas balloons, the Coupe Gordon Bennet, a distance competition born over a century ago that takes place every year.

The gas balloon is formed by a spherical envelope on top of which there is a large valve very similar to that of hot air balloons while below there is a sleeve for the gas to escape. The wicker boat is hung from the casing. To fly, the balloon is filled with gas (hydrogen) in order to obtain an upward thrust greater than the total weight of the balloon. This thrust is compensated by the weight of the ballast (bags filled with sand) hanging outside the spacecraft. Navigation is the result of the balanced use of gas leakage to lower altitude and ballast discharge to ascend. The flight ends when the remaining ballast will allow a controlled descent. Once on the ground, the residual gas from the balloon is completely dispersed. Compared to the hot air balloon, the gas balloon has higher operating costs as well as a more complex preparation. However, its flight range far exceeds that of a hot air balloon and allows you to fly in absolute silence.

THE AIRSHIP

The airship is a balloon with a typical torpedo shape which, unlike aerostatic balloons, can be steered in one direction and determined thanks to the thrust of engines and the presence of directional rudders similar to those of aircraft. The first airship with a steam engine was built by the Frenchman Henri Giffard in 1852. Subsequently, electric and internal combustion airships were created.

In 1898 the first Zeppelin filled the sky with history. Airships experienced their maximum expansion between the beginning of the 20th century and the Second World War, being the fastest means of transport over long distances at that time. They were used to transport passengers and precious goods to bring Europe and the United States closer together. The creation of the first airship was the work of the French, however the Italians were always at the forefront in study and design even though they were unable to complete the prototypes due to lack of funds and inadequate infrastructure.

The first airships had rigid, semi-rigid or flexible structures and the casing was made of layered fabric and covered with rubber. Very large in size, they required immense hangars (the largest Zeppelins reached 270 meters in length and 45 in height) and had significant problems with maneuverability and weather management. In addition to the danger of the hydrogen with which they were entirely inflated. The history of large airships ended tragically in 1937 with the disaster of the Hindenburg, pride of aviation in the time of the Reich, destroyed by a serious fire which caused the death of over 36 of the 97 passengers on board. The history of the airship will have an important setback after the war when they were replaced by new aircraft, which had become faster and safer.