Lonely Planet Writer

What causes turbulence, and what do airlines do to avoid it?

Turbulence can be unsettling or even worrying in flight, especially if you’re already a nervous flyer — and even if you’re not. So I sat down with Finnair’s Fleet Chief Pilot Marko Valtonen, and asked him what causes turbulence to begin with, what airlines do about it, and how they’re working hard the make flights even smoother.

Turbulence pattern in the clouds
Wake turbulence vortex of cloud created by passing airplane. Photo by: Nutkamol Komolvanich

So, scientifically, what is turbulence? “Various weather phenomena, such as cumulonimbus clouds and weather fronts cause vertical wind shifts in the troposphere. In other words,” Valtonen explains, “disturbances in air flow are experienced as turbulence in the cabin.”

“On the ground you can’t see the turbulence, unless it is connected to weather phenomena like cumulonimbus clouds or weather fronts,” he says.

It’s normal, Valtonen notes, if it’s a bit bumpier at the beginning and end of the flight. “Takeoff and landing are more turbulent than cruise. The reason for this is that the roughnesses of the earth’s surface, as well as temperature differences, cause plenty of flow disturbances.”

But be reassured: “Airlines’ flight dispatch make flight planning according to the detailed information about the individual aircraft and available weather data from specific sources for aviation, like METAR and TAF, which provide detailed weather info per destination airport as well as larger scale weather forecast.”

How do pilots avoid turbulence?
‘Turbulence is a harmless phenomenon’ says Finnair pilot. Photo by: Theerawat Kaiphanlert

METAR (METeorological Aviation Report) and TAF (the Terminal Area Forecast) are two different types of the many weather forecasts created for airlines at specific airports. There’s a whole industry involved in making your flight smoother and more comfortable.

“During the flight,” Valtonen says, “pilots get latest weather data and updated forecasts. Aircrafts’ radar show thunder storms and they are bypassed — also the heavy turbulence, due to passenger comfort. The best info about turbulence when en route is obtained via other aircraft notifications. Aircraft also send automatically wind and weather data to airlines. This info is used in making forecasts.”

Indeed, some planes carry special weather sensors that feed into a global live picture of weather that also enables more specific forecasts to be created, making it easier to avoid turbulence.

“There are many new applications regarding weather phenomena affecting flight. Part of Finnair’s fleet is already connected during flight. In future there will be chances to use some applications during flight to assess newest forecasts concerning turbulence,” Valtonen says, and new systems are arriving all the time. “The first application will be rolled out in Finnair A350 fleet this week.”

Turbulence can be uncomfortable, but not dangerous
Turbulence can be uncomfortable, but it’s normal. Photo by: Pone Pluck/Getty Images

Valtonen is clear that passengers should feel reassured that turbulence is normal, that aircraft are built for it, and that crew are trained for it.

“Turbulent weather feels uncomfortable, it can be annoying, but mainly it is a harmless phenomenon,” he says. “Aircraft have been built to [deal with] sudden strain caused by turbulence. For example, the wings are designed to be flexible, and they bob up and down. Due to this flexibility, the wings will not fracture or change shape, and neither will bumps destroy wing lift.”

At the end of the day, as for every airline, “flight safety and passenger comfort are vital for Finnair. This is why our pilots have been trained to anticipate and avoid the worst areas,” Valtonen concludes.

So if you feel nervous the next time it gets bumpy, take a deep breath and try to remember that aviation professionals have spent untold hours planning and training to fly safely in turbulent conditions.