Turbulence is a concern that has bothered every air traveler at least once in their life. It might not be one of the most pleasant experiences for the passengers, when the aircraft cabin is shaking as if you were sitting in a car that is driving on a bumpy road. However, the main reason why turbulence causes so much fear among passengers is that most of them don’t understand what causes turbulence. The travelers might not be well aware of how the pilots are trained to manage it, and how the airplanes are designed and built to handle it.

Important facts about turbulence

Turbulence could be considered as one of the great mysteries of physics. Both mathematicians and physicists have not been able to solve the turbulence mystery yet. Turbulence is often referred by scientists to as chaos. It occurs when bursts of energy get into the air the plane is flying through. This energy causes changes in the pressure and speed airflow which leads to powerful air currents that move in different directions. If an aircraft gets into such streams, it might seem that the jet is falling (this is called a somatogravic illusion where the brain interprets a deceleration as the plane pitching down, when in fact, the change in height hardly reaches several meters) or bounces on a particularly steep bump.

There are three main factors that cause turbulence-related air flows :

  • Shear, such a turbulence occurs when two adjacent areas of air move in different directions. The border between them can be a turbulence hotspot. A common cause of shear is jet flow from another airplane, also called wake turbulence.
  • Thermal turbulence is caused by the heat which rises and heads up through the cooler air. Thermal turbulence could be related to clear-air turbulence, which is considered one of the most dangerous as it is impossible to predict or notice.
  • Mechanical turbulence is caused by large structures on the ground, such as mountains.
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Planes usually experience turbulence when flying through pockets of raising and falling air called eddies. They are formed along the edges of the thunderstorm front, which the plane is trying to bypass. These eddies are not visible on the radars, and it is hard to determine the boundaries of the turbulence zone in advance and correct the route on the ground.

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Turbulence can also occur during landing when the plane encounters strong headwinds and side winds. It is felt more strongly at lower altitudes, and weaker at higher altitudes. The larger the airliner, the less noticeable the turbulence.

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There are varying degrees of turbulence depending on its intensity:

Weak, that can cause a little discomfort but does not disrupt the normal course of the flight.

Medium - more uncomfortable that makes walking around the cabin difficult as you can hit something or somebody by accident or even get injured. Just like on a bus during hard braking or cornering. To avoid accidental injury, the captain turns on the signal "Fasten your seat belts." In case of moderate turbulence, we will also ask for seats and flight attendants.

Severe turbulence is the only category of turbulence that can be considered dangerous, as pilots might temporarily lose control of the machine.