Clear Air Turbulence: When the "Invisible Sea" Gets Rough

We would all love for every flight to be "smooth as silk," but unfortunately, you may encounter conditions that literally make the cabin tremble—almost as if a giant hand had grabbed the plane and started shaking it like a rattle. You look out the window, and there isn’t a cloud in the sky! What is actually happening?

The truth is that the air the plane moves through, though invisible, is still a fluid and behaves much like the sea: it has its waves, its currents, and its rough patches.

The Jet Stream: Rivers of Air

Thanks to modern technology, it is often possible to predict the location of these phenomena along the route with good accuracy, allowing pilots to avoid them or use them to their advantage. Yes, to their advantage! For example, if we manage to enter a "river of air" (technically called a "Jet Stream") flowing in the direction of our route, it allows us to travel much faster, reducing flight time, fuel consumption, and pollution.

Conversely, we avoid flying "upstream" as much as possible. A jet stream can easily reach speeds of 200 to 300 kilometers per hour! The "edges" of these currents—where the air transitions from a state of rest to high velocity in a short distance—are often very turbulent and are therefore avoided.

Le correnti a getto intorno al globo

CAT and Mountain Waves

There are many other causes for what is known as "Clear Air Turbulence" or CAT. These range from actual waves caused by fast air currents passing over mountains (called mountain waves), which can be encountered even at high altitudes, to areas where warm and cold air masses meet (called "fronts").

It goes without saying that areas near large clouds are another source of turbulence. Not to mention the interior of the most towering clouds (cumulonimbus), where turbulence could even become dangerous.

Can the Plane Handle the Stress?

Admittedly, while crossing a turbulent zone, looking out the window and seeing the wing and engine moving up and down is not pleasant at all...

Rest assured: it is a good thing they move that way! It is precisely this "elasticity" that allows the structure to withstand the stress. If the plane were a totally rigid body, it would eventually snap (see this post).

However, it is extremely important to keep your seatbelt securely fastened during turbulence. Without it, in extreme cases, you could easily be thrown against the cabin ceiling and then fall back painfully into your seat!

DontWorryFlyHappy!