What Causes Turbulence on Flights?

Flying can be inherently scary. After all, humans evolved two legs to stand on instead of wings to fly with. This complete lack of a biological disposition toward flight makes discomfort in the air understandable. Those small in-air motions and various forms of turbulence that wouldn’t make a bird blink are completely foreign sensations to the human body.

Fortunately, humans also evolved with advanced brains, and that ability for understanding is exactly what’s needed to work through turbulence-induced flight anxiety. Here’s what causes turbulence and what you should know about it on your next flight.

What is turbulence on planes?

Turbulence happens when there is a sudden change in airflow. It’s characterized by air moving in eddies and currents, much like water.

Airplane turbulence can occur for a wide range of reasons, like air movement over mountains or shifts in the weather due to nearby storms. But the most common reason for bumps is not scary: It’s “clear-air” turbulence that occurs when cool and warm air collide. The resulting impact on airplanes is measured as light, moderate, severe, or extreme. In an interview with the Points Guy, commercial pilot and AskThePilot.com host Patrick Smith explains, “80 percent of turbulence [in] commercial aircraft experience is light.” In fact, Smith has never experienced extreme turbulence in his career and has only been through severe turbulence a few times.

How much passengers notice these changes in airflow depends on the size of the object being affected by them. Measuring from microscopic to the size of hurricanes, “air at all scales is filled with lots of these vortices,” explains Bret Tobalske, associate professor of Comparative Biomechanics at the University of Montana. A vortex needs to be roughly the size of the object it’s affecting to be noticeable. These vortices even happen on the ground, but since wind typically isn’t powerful enough to knock a person over, we don’t notice it. But when we do, “that’s telling you that the turbulence, the scale of those circulating eddies, are about [human] sized,” Tobalske says. Along that line of logic, airplanes experience turbulence when they come into contact with airplane-size wind vortices.

During turbulence, planes might feel like they’re shaking from side to side or move like a car going over a bumpy road. A common sensation during a turbulent episode is that the plane is dropping. However, because most passengers don’t fly frequently enough to be familiar with the nuances of air movement, how far the plane drops tends to be overestimated.

According to pilot Smith, “In the minds of the passengers, the plane is plummeting hundreds or thousands of feet, but we might only see a twitch of 10 or 20 feet on the altimeter.” It’s important to remember that these sensations are caused by the movement of air, as opposed to a mechanical malfunction or impact with a physical object.

Photo by Skycolors/Shutterstock

Is it safe to fly in turbulence?

Turbulence is relatively common and safe to fly through. Although there are occasional news reports of turbulence that turned dangerous (like a recent Lufthansa flight where seven people were sent to the hospital), it’s usually harmless. According to Federal Aviation Administration data, only 30 passengers and 116 crew members received serious injuries from turbulence between 2009 and 2021.

Most turbulence is light, so when stories of intense airplane turbulence hit the news, it’s because those scenarios are rare enough to be deemed newsworthy. However, understanding statistical likelihoods doesn’t always help cure flight anxiety, which is why it’s important to understand turbulence and how little it affects airplanes.

Do pilots know turbulence is coming?

While pilots can’t actually see turbulence, they often know what is coming up, thanks to reports from other planes, weather reports, and radar equipment.

However, clear air turbulence (severe turbulence occurring in cloudless areas) can sometimes catch pilots off guard. And as the climate continues to warm, there will be a higher percentage of clear air turbulence. That’s why it’s important for passengers to wear their seat belts when they’re not moving about the cabin to avoid injury.

How to relieve anxiety about turbulence

Although we may want to close our eyes at the thought of turbulence, ignoring it can perpetuate anxiety. “Because of our lack of knowledge about what turbulence actually is, we struggle to understand if it’s just annoying or actually dangerous,” says Stephanie Smith, a clinical psychologist and public education coordinator in Colorado for the American Psychological Association. Understanding turbulence is the first step toward demystifying it. “This can help us avoid jumping immediately to worst-case scenarios and panic responses,” she explains, like thinking the plane has collided with something or the engine has given out.

Even when turbulence causes the plane to drop only a few feet, the unfamiliar sensation can feel more dramatic. “When a flight changes altitude in search of smoother conditions, this is by and large in the interest of comfort. The pilots aren’t worried about the wings falling off; they’re trying to keep their customers relaxed and everybody’s coffee where it belongs,” says Patrick Smith. So what can feel like turbulence is often just pilots moving the plane out of the way of shifting air pockets. Plus, commercial airliners are engineered to withstand far more than nature can throw at them: Boeing famously showed what it takes to destroy a perfectly good 777 to prove that commercial jets can endure stress well beyond what can happen in real life.

Preparation is key to making turbulence seem as mundane as it actually is. “Practice healthy stress management strategies while you are not flying so that you will be an expert at using them while you are flying,” advises psychologist Smith.

Therapy to address overall anxiety can be effective before a trip, as is taking classes geared toward overcoming the fear of flying. Turkish Airlines, for instance, offers a multiphase program that familiarizes students with airplanes and their various quirks, with the assistance of mental health professionals. The in-person program is $500 and open to the general public.

There are similar on-the-ground courses around the world, typically based near a major airport, including one in San Francisco. Often, knowing what to expect and having the chance to become comfortable with the idea of it before it actually happens can make those bumps less daunting.

In the air, Turkish Airlines’s Fly Good Feel Good project addresses the needs of passengers as they experience flying stress by taking a holistic approach to flight anxiety, incuding a tea specifically brewed to create calm. Whichever airline an anxious flier is on, targeting stress through nutrition (by minding what you eat), exercise (to relieve tension), and psychological methods (like meditation and breathing exercises) are effective ways to treat flight anxiety.

Turbulence may be uncomfortable, but, hey, nothing in life comes without a few bumps along the way.

This article was originally published in 2018 and was most recently updated on March 23, 2023, with new information. Bailey Berg contributed to this reporting.