Snap on that seat belt: What really happens during turbulence


How many times have you heard your pilot say something like, “It’s a little bumpy, so we’re going to leave the seat belt light on”? Airline customers hear this phrase so often, it can be easy to disregard. After all, turbulence is no more than a little gentle shaking every now and then, right? While this is true most of the time, keeping your seatbelt fastened even when the flight is smooth is the best thing you can do for your own safety, because turbulence can strike unexpectedly.

Woman Adjusting Seatbelt

What’s Going On?
In the aviation world, the winds that cause a bumpy ride are known as turbulence, and not the imaginary “air pockets” that non-pilots sometimes refer to. Turbulence is simply the unexpected movement of air, and it can be caused by a number of things. The most common type of turbulence is called thermal turbulence, which is caused by hot air rising and cool air descending. Planes also frequently encounter mechanical turbulence, which is when mountains cause disruptions in airflow, much like the rapids caused by a river flowing over large rocks.

Less common forms of turbulence include the dramatic changes in wind speed and direction called a shear, and the aerodynamic and wake turbulence caused by other aircraft (think of it like a motorboat crossing too close behind another vessel). We often associate turbulence with storms and other bad weather, but there’s also an important phenomenon called clear air turbulence that can strike at any time with little or no warning.

How Turbulence Affects a Jetliner
Turbulence is such an important subject that the aviation field defines each event based on its severity. Light turbulence will cause slight changes in direction—pilots report this as “light chop.” For customers, this might result in momentary discomfort with little or no difficulty walking around the cabin.

Moderate turbulence is when food and other unsecured objects begin to move around, and walking down the aisle becomes difficult. Severe turbulence can cause customers to be uprooted from their seats if unbelted, which is why keeping your seatbelt securely fastened is always a good idea.

Why Seat Belts Make Sense
The vast majority of times a pilot illuminates the fasten seat belts sign, the aircraft will only experience light or moderate turbulence—which rarely causes injuries. Unfortunately, there’s no way for pilots or customers to know when light or moderate turbulence could instantly become severe. At that moment, simply having your seat belt buckled could prevent injury. And not only is it smart, it’s required. FAA regulations mandate that passengers be seated with their seat belts fastened whenever the seat belt sign is illuminated during flight.

Seatbelts Make for a Smoother Flight
During even light and moderate turbulence, having your seat belt fastened will minimize your body’s movement and actually make you more comfortable. If you’re a nervous flier, this means the difference between stressing over every little bump and relaxing into your seat for the ride. The seatbelt light might not be on, but you can rest assured that if unexpected turbulence does hit, you’ll be secure in your seat until it passes.