2024-05-11 13:36:37
The recent accident, when a hot air balloon with people fell in Šilute district, is not the first such accident in the history of our country. In order to understand how such disasters can happen and how they can be prevented, it is necessary to know a few things.
Design features of air balloons
Since the time of the Montgolfier brothers in the 18th century, who were the first to build and launch a hot air balloon, the design of hot air balloons has remained largely unchanged. The modern design of a hot air balloon consists of three main elements:
The dome. It is made from strong nylon materials such as polyester or polyamide. To make the fabric airtight, the other side is covered with a moisture-resistant material (usually polyurethane). For strength and rigidity, the body is covered with strips in vertical and horizontal directions. The dome has an opening to fill with air and a special valve to release the air. The size and number of dome segments determine the bearing capacity of the structure.
Burner (one or more). The burner heats the air under the dome and thus inflates the device. Gas (mainly propane) is used as fuel. Modern burners are protected by special covers and have a reliable adjustment mechanism. The balloon rises due to the heating of the air in the dome.
Gondola. This structural element is designed to carry passengers or cargo. The materials from which the gondolas are made are weather-resistant and can withstand a lot of weight. The gondola is attached to the dome with special cables.
Balloon preparation and flight
First, the balloon is laid on its side, then the dome is extended. The burner is lit and the air heating process begins. The heated air fills the shell of the sphere, rises and gradually lifts the entire dome and then the nacelle.
The pilot and passengers climb into the gondola, which is untied from the ground. The flight begins. By decreasing and increasing the temperature inside the dome, the pilot adjusts the flight altitude. As the air inside the dome cools, the balloon begins to gradually descend.
To accelerate the landing, the pilot gradually releases hot air through a valve on the side of the dome. The flight course is regulated through this valve.
The influence of the environment and weather conditions on the flight
The environmental conditions have a strong enough influence on the flight in a hot air balloon. Balloons can be released all year round, at any time of the year when the wind is no higher than 5 m/s, there is no precipitation and storm clouds. The period from the beginning of April to the beginning of November is more favorable and safer for flights.
During this period, there is more daylight, which allows flying in the morning and evening, as well as more days when the weather is favorable. As a rule, flights are carried out in the mornings and evenings, because at that time there are usually no sudden flows of air masses, that is, gusts of wind.
If we talk about the disaster in Šilute area, according to publicly available information, at the time the flight was underway, meteorological radars recorded storm clouds. Although the aforementioned clouds were far enough away at the initial moment, as can be guessed, their rapid movement caused the disaster to occur.
The importance of balloon pilot skills
The pilot of any hot air balloon, like the commander of any aircraft, is fully responsible for the safety of the flight. They must pass the relevant exams, must have experience in aviation, ie, basically, the balloons are piloted by experienced pilots.
It is difficult to say what influenced such uncontrolled release. Without concrete information, one can only try to guess what happened. The accident may have been influenced by rapidly changing weather conditions. The sudden cooling of the air and the gusts of air should have pushed the balloon down suddenly, and then it is already difficult enough to control the flight. Crashed on the ground or close to its surface, the balloon was still filled with enough hot air to affect the drag of the balloon.
In addition, during such distractions in the air, there may have been inadvertent interference from other passengers in the pilot’s control of the flight – imagine what can happen in a gondola during a sudden descent and distraction. The passengers could accidentally push the pilot away from the burner and valve as they fell, a loss of control of the balloon’s flight that the pilot likely already had no control over.
However, the pilot (in this case, the female pilot) could have paid more attention to assessing the weather situation. When transporting passengers, you need to be extremely careful and attentive. As mentioned, in one way or another, the pilot of the aircraft is responsible for safety.
The author of the text is a lecturer of the Aviation Engineering study program at the Faculty of Mechanical Engineering and Design of KTU, Assoc. Saulius Japertas.
2024-05-11 13:36:37