What Is Turbulence And How Can It Affect Your Flight?

Air travel is one of the safest forms of long-distance transportation, but nearly every traveler has experienced the terrifying moment when the plane seems to suddenly drop or begins to shake during a flight. It’s not uncommon to experience turbulence during air travel. But what exactly is turbulence? Is it actually dangerous?

(​MORE: Passenger Dies After Private Jet Hits 'Severe Turbulence')

“Turbulence is caused by moving air currents that happen with many different kinds of weather conditions: pressure differences, jet streams, wind shear, air moving around mountains, rising warm air and sinking cold air, surface fronts and thunderstorms,” said Dina Knightly, weather.com senior geographical meteorologist.

But severe weather or storms don’t have to be present for a flight to experience turbulence. According to the Federal Aviation Administration, turbulence can happen unexpectedly, even when skies appear clear.

Thermal turbulence can occur when an airplane encounters warm rising air or cold sinking air. Air moving around mountains or other geographical features can cause mechanical turbulence as well.

There is also clear air turbulence, which usually occurs above 15,000 feet. This type of turbulence can happen in a cloudless sky and occurs when an airplane flies through changes in wind speeds due to wind shear or jet streams.

“As an airplane moves through the atmosphere, lift is created by differences in pressure on either side of the aircraft’s wing. Whenever these are disrupted, an airplane can be bounced upward or downward,” Knightly said.

(​MORE: Lufthansa Flight Hits 'Significant Turbulence;' 7 People Hurt)

There are several ways turbulence can affect a flight:

• Damage to the structure of the aircraft.

• Injury to passengers or crew.

• Difficulty for the pilots to perform flight duties, such as reading instruments.

• Sudden changes in altitude and airspeed.

At flight cruising levels (typically between 33,000 and 42,000 feet), about 3% of the atmosphere has light turbulence, while 1% has moderate turbulence, NPR reported, citing Paul Williams, a professor of atmospheric science at the University of Reading. Only a few tenths of a percent have severe turbulence.

The FAA reports that 146 people were seriously injured by turbulence from 2009 to 2021 aboard regular commercial flights.

According to the National Transportation Safety Board (NTSB), “Turbulence-related accidents are the most common type of accident involving commercial airlines.” From 2009 through 2018, the NTSB found that turbulence-related accidents accounted for more than a third (37.6%) of all commercial airline accidents.

A 2021 NTSB report found that the majority of passengers seriously injured by turbulence weren’t wearing seatbelts, often because they were in the restroom or traveling the aisle when the turbulence struck.

Last week, a passenger died after a private plane hit “severe turbulence,” according to officials. Prior to this incident, there had not been any turbulence-related deaths on commercial flights since 2009, according to NTSB data. CNN reported that there have been 38 turbulence-related deaths involving private planes since 2009.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.