At least one person was killed, and dozens injured when a Singapore Airlines flight hit turbulence on Tuesday, renewing questions about how turbulence can impact air travel and the safety measures that can be taken to avoid injury.
It’s not yet known exactly what caused the death of the 73-year-old man on that flight or if it was directly tied to turbulence, but passengers have said the plane dropped suddenly and it caused some passengers to be launched into the ceiling, leaving dents in the overhead baggage holds.
It’s why former Transport Canada flight safety inspector Jock Williams says it may seem like simple guidance, but keeping your seatbelt fastened throughout the flight is imperative.
“You can be sitting in your seat and your seatbelt is as tight as you can comfortably have it. That way you can’t get thrown against the overhead,” he said. “But anybody who’s just walking around loose takes on the velocity that the airplane is going — only he’s going towards the roof.”
What causes turbulence
When people fly, they can notice bumpy conditions as a flight goes through a patch of turbulence. Most are minor, and airlines have made steady improvements to reduce accident rates from turbulence over time.
Turbulence is the irregular motion of the air, resulting from eddies and vertical currents, according to the National Weather Service, and usually comes from heavy storms or flying over mountain ranges.
Pilots often try to avoid such turbulence by flying around storms or through other plotted courses.
What can be difficult, if not impossible to avoid is what’s known as clear-air turbulence, often found in or near the high-altitude rivers of air called jet streams. The culprit is ‘wind shear’, when two huge air masses close to each other move at difference speeds. If that’s big enough, the atmosphere is unable to handle the strain and it breaks into turbulent patterns.
“When you get strong wind shear near the jet stream, it can cause the air to overturn. And that creates these chaotic motions in the air,” Thomas Guinn, chair of applied aviation sciences department at Embry-Riddle Aeronautical University in Daytona Beach, Florida, told The Associated Press.
The problem for pilots, Williams told Global News, is it’s very difficult to know if or when they will hit such turbulence.
“It’s impossible to avoid unless somebody has hit it already and warned you, because you can’t see it. It doesn’t show up on radar, doesn’t show up on any mechanism that we have in the cockpit to avoid it,” Williams said.
Tracking turbulence-related injuries globally can be difficult, however some countries like the U.S. and Canada publish data.
In Canada, the Transportation Safety Board told Global News there have been 56 incidents reported since 2015, with nine involving serious injuries. However, none have involved deaths, though the TSB noted one incident — an Air Canada flight in December 2015 — that required an investigation when several passengers were not wearing their seatbelts.
The National Transportation Safety Board in the U.S. says 163 people were injured seriously enough to require hospital treatment for at least two days between 2009 and 2022.
Geoffrey Thomas, an analyst with airline safety and product rating site Airlineratings.com, told Reuters in the wake of the Singapore Airlines incident changes should be made at least when it comes to seatbelts on board.
“Airlines saying, ‘We recommend you keep your seatbelt fastened while seated,’ should be saying it is mandatory to keep your seatbelt done up,” Thomas said.
Can climate change impact turbulence?
Some scientists note that reports of turbulence encounters are on the rise.
There are a number of possible explanations for that, but several researchers have pointed to potential climate impacts.
Guinn explained that some predict climate change could alter the jet stream and up the wind shear, which would consequently drive-up turbulence.
In a statement to the Associated Press Tuesday, Paul Williams, a professor of atmospheric science at the University of Reading in England, said there was “strong evidence that turbulence is increasing because of climate change.”
Williams said his research team discovered in 2023 that severe clear-air turbulence in the North Atlantic has increased by 55 per cent since 1979, for example.
The team’s latest projections signal that severe turbulence in the jet streams could double or triple in the coming decades if global conditions continue as expected, he said.
—with files from The Associated Press and Reuters