What is turbulence?

*Ding* “Ladies and gentlemen, this is your captain speaking. We just turned on the fasten seatbelt sign due to reports of some choppy air ahead. We should have it back off in about 20 minutes.” If you’ve flown, you can bet your bottom-dollar you’ve encountered at least some level of turbulence. While turbulence does make some people uneasy, understanding what causes that rough air can help take the edge off.

Turbulence is defined as the unsteady movement of air (or water), and changes in wind speed or direction can be caused by any number of weather phenomena.

Air moves much like water and turbulence can by created in any instance in which two different flows of air are mixed. People often think of storms as the primary cause of turbulent air, but there are other causes as well. Clear-air turbulence, which lacks any visual cues such as clouds, is a relatively common cause of turbulence. Even though this sort of turbulence is invisible, pilots and dispatchers (those who make flight plans) can use wind data to fly around areas that are prone to this type of turbulence. On hot days, thermals (currents of warm air that move upward rapidly) can cause turbulence, and flying over mountains or even hills can also be turbulent because air has to move around them, resulting in updrafts or downdrafts.

It is comforting to know that pilots and Air Traffic Control (ATC) are always working together to keep your flight as smooth as possible. There is more weather data available today than ever before to help flights avoid rough air. This information not only helps pilots and ATC know what types of weather are more prone to the creation of turbulence, but also helps them see and avoid it. The weather radar in modern jets allows pilots to scan what’s directly ahead at their altitude and altitudes above and below the aircraft. Pilots and dispatchers have the discretion to fly hundreds of miles out of the way just to give you a smoother ride. Here’s a great example of an AVL-bound jet making a slight deviation en-route to avoid a thunderstorm.

Additionally, pilots often provide Pilot Reports (aka, PIREPs) of flight conditions, so aircraft passing through the same airspace know what to expect or avoid — you can see some examples here and here. Given the number of planes flying, there are thousands of PIREPs every day, helping your flights find the smoothest air. That’s how your pilots often know about turbulence ahead of time and are able to climb or descend to avoid it.

Turbulence is never truly as rough as it may feel to a passenger. In fact, even “severe” turbulence typically only involves altitude changes of 20–40 feet. Aircraft are built to endure much more punishment than they ever endure during commercial flights. In fact, modern aircraft are designed to handle forces 1.5 times stronger than any recorded in the past 40 years of flight. When flights re-route around turbulence, it’s largely for your comfort, as the aircraft would handle the ride just fine. No matter how bumpy your flight gets, the structure of the airplane is far from ever becoming stressed. You can see just how much the wings of modern jets like the Boeing 787 are tested here.

If you’re a nervous or anxious flier, there are many things you can do to help yourself enjoy the flight. You should always try to sit where you’ll be most comfortable. Even on sold-out flights, if you let the gate agent know ahead of time that you really want a window, they’ll try to accommodate you. Make sure you bring along a movie, some snacks, ear plugs and any other creature-comforts that you’d want in any scenario where you’d be sitting for hours. There are apps and online guides (like this one) that’ll help you find other ways to make your trip as enjoyable as possible.  And always – keep that seatbelt fastened when you are seated.

The next time your flight encounters turbulence, loosen your grip on that armrest and remember that you’re experiencing a perfectly routine part of flight — the safest form of travel in human history. In fact, statistically, air travel has been increasing its lead as the safest form of travel for decades. So sit back, relax and enjoy the flight!