Le Fatum Innovative Experiment in the Search for Air Balance

Le Fatum, created by Santos=Dumont and Emmanuel Aimé

In July 1901, a crucial meeting for aeronautical exploration was held, bringing to the scene several enthusiasts and pioneers of flight. Among those present were notable names such as Emmanuel Aimé, Alberto Santos-Dumont, Georges Besançon, and many others. The meeting was marked by an outstanding test that was conducted with the "Fatum" balloon.

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The "Fatum" was an auxiliary spherical balloon, built with an innovative balancing thermostat system, developed by Emmanuel Aimé and Alberto Santos-Dumont. The intent behind this pioneering test was to explore ways to control the balloon's rise and descent with greater precision, without relying entirely on traditional sand and/or water ballast.

Test of the Fatum L'Aérophile, July 1901

The "Fatum" balloon had a unique configuration. With a volume of about 50 cubic meters and a diameter of 2.50 meters, the thermostatic cylinder was shaped like an auxiliary balloon made of a light material known as "frou-frou".

Half of the cylinder's surface was white, while the other half was black.

This cylinder was open at the bottom and closed at the top, and its structure was composed of two cylinders suspended from the sides of the main balloon, balanced by a bamboo that rested on the circumference of the balloon.

Test of the Fatum L'Aérophile, July 1901

The operation of the balancing thermostat was based on the interaction of solar radiation with the thermostat's black cylinder. When the sun acted on this part, the internal air expanded, causing the system to rise to a higher altitude, which makes the thermostat efficient only on clear and sunny days.

During the test, the "Fatum" was launched from the Parc d'Acrostation de l'Aero-Club, initially heading towards Sèvres. As it rose, the thermostatic cylinder was activated, raising the system to an altitude of one thousand meters. However, as the clouds passed the sun, the thermostat was temporarily disrupted.

The results of the tests with the "Fatum" were impressive, but also revealing, it was clear that the balancer thermostat had a remarkable potential to control the ascent and descent of balloons, providing greater autonomy and precision, but the dependence on solar radiation limited its effectiveness. to sunny days, which presented a significant challenge.

While the results of the balancer thermostat were promising, its dependence on solar conditions highlighted the need to continue the search for more effective methods of controlling balloons and aircraft. The story of "Fatum" serves as an inspiring reminder of how the courage to push boundaries and the creativity to develop unique solutions can drive progress and innovation in the quest for human flight.

Operation

The functioning of the balancing thermostat in the form of a "frou-frou" (accordion-shaped) tube was directly linked to the regulation of the internal temperature of the "Fatum" balloon and, consequently, to the control of its ascent and descent. This balancing system was designed to exploit the properties of air heated by the sun, creating a way to control the balloon's buoyancy.

The operation of the balancing thermostat was based on the interaction of solar radiation with the auxiliary tube with black and white faces of the thermostat - when the sun heats the black side of the auxiliary balloon, the frou-frou expands and the balloon rises. And when, in turn, the tube with its white side is away from solar radiation, the air cools down and the balloon descends.

When the black part of the thermostat, which consisted of a cylinder of light and expandable material, was exposed to direct solar radiation, it absorbed heat, causing the air inside to expand. This increase in the volume of the internal air resulted in a decrease in the density of the air inside the thermostatic cylinder, making it lighter in relation to the ambient air.

With the thermostatic cylinder expanded and lighter, the tendency was for it to stretch, increasing the length of the accordion part.

This stretching created an upward force, aiding in the process of lifting the "Fatum" balloon. The main balloon, in turn, was balanced by the weight of the thermostatic cylinder and other parts of the structure, as mentioned in the previous description.

As the "Fatum" balloon rose and gained altitude, the thermostatic cylinder continued to absorb solar heat, remaining expanded and elongated, this resulted in a constant upward force that helped to counterbalance the weight of the main balloon and the passengers, allowing for the balloon to rise to desired altitudes.

On the other hand, when the balloon needed to descend, the "frou-frou" was collected with the white part facing the sun, the cooled air became denser and heavier, reducing the thermostat's buoyancy force and allowing the balloon to begin to descend gradually.

Although the balancer thermostat showed promising potential for regulating the altitude of the "Fatum" balloon, its effectiveness was limited to solar conditions. On cloudy days or at night, when solar radiation was not present, the thermostat did not work, and the balloon depended more on traditional sand and/or water ballasts for altitude control.

Moments of Tension

In one of the most tense moments during the test of the "Fatum" balloon, an incident occurred when the balancer thermostat was loose next to the main balloon. This episode demonstrated the complexity and challenges associated with pioneering aeronautical experimentation.

While the "Fatum" balloon was ascending with the thermostatic cylinder suspended beside it, a risky situation occurred when the auxiliary balloon became agitated and out of control, threatening to tear the main balloon. Setting up the balancing thermostat involved suspending the thermostat cylinder from either side of the flask, balanced by a bamboo that rested on the circumference of the flask. However, at a certain point, atmospheric instability or other unforeseen circumstances may have led the airship to dangerously approach the main balloon.

The proximity of the airship to the main balloon represented a potential threat, as it could result in collision or interference with the structure of the balloon, compromising the safety of the experiment. The situation required quick and decisive action on the part of those involved to avoid any damage or accident.

While "Le Fatum" was ascending with the thermostatic cylinder suspended beside it, a risky situation occurred when the auxiliary balloon became agitated and out of control, threatening to tear the main balloon.

While the detailed description of this incident was not provided in the shared excerpt, it highlights the challenging and unpredictable nature of aerial exploration at that time. Aeronautical experimentation was fraught with uncertainty and risk, with pioneers facing a number of obstacles as they sought to understand and control flight.

Ultimately, the test of the "Fatum" balloon represented an important milestone in the history of experimental aeronautics, showing the capacity for innovation and the constant search for creative solutions in the search for controlled flight. The meeting of brilliant minds like the great friends Dumont and Aimé, and the results obtained contributed to the continuous evolution of aerial technologies and laid the foundations for future explorations in the field of aerostation.