An expert on the hot air balloon disaster: the actions of the passengers could have contributed to the fall

Thanks to the relief of the country, Lithuanians can enjoy the entertainment of hot air balloons, unfortunately, sometimes such flights end in disasters. According to the lecturer of the Aviation Engineering study program at the Faculty of Mechanical Engineering and Design of the Kaunas University of Technology (KTU), Assoc. Saulius Japert, it is important to emphasize that balloon management is a complex activity.

The accident that happened this week, when a hot air balloon with people fell in Šilutė 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

According to Assoc. S. Japert, since the time of the Mongolfje brothers, who were the first to build a balloon and take it into the air in the 18th century. the design of the balloons remained largely unchanged. The modern design of a hot air balloon consists of three main elements:

1. 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 for filling with air and a special valve for releasing the working medium. The size and number of dome segments determine the bearing capacity of the structure.

2. 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.

3. 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.

Assoc. Saulius Japertas. KTU photo

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.

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 influence of the environment and weather conditions on the flight

Environmental conditions have a strong enough influence on hot air balloon flight. Hot air balloons can be flown all year round, at any time of the year when the wind is not higher than 5 m/s, there are 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 mentioned clouds were far enough at the initial moment, as can be guessed, their rapid movement made the accident happen,” said S. Japert.

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, that is, basically, the balloons are piloted by experienced pilots.

“It is difficult to say what has influenced such an uncontrolled release. Without concrete information, one can only try to guess what happened. The accident could 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 near its surface, the balloon was still sufficiently filled with hot air to cause the balloon to drag on the ground. Also, 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. Falling passengers could accidentally push the pilot off the burner and valve. And this is the loss of control over the flight of the balloon, which the pilot probably could not influence. 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”, said the expert.