That seat belt sign could become mandatory during entire flights going forward, all thanks to increased turbulence due to unchecked climate change.

More than 140 passengers and crew from a Singapore Airlines flight, which experienced severe turbulence that left dozens injured and one person dead, finally arrived in Singapore on a relief flight Wednesday morning after making an emergency landing in Bangkok.

The scheduled London-Singapore flight on a 777-300ER aircraft was diverted to Bangkok due to turbulence that violently tossed passengers and crew around the cabin, causing some to slam into the ceiling.

A 73-year-old British passenger suffered a suspected heart attack and died, while at least 30 others sustained injuries.

“I saw people from across the aisle going completely horizontal, hitting the ceiling, and landing back down in really awkward positions. People were getting massive gashes in the head and concussions,” recounted Dzafran Azmir, a 28-year-old student onboard the flight, after arriving in Singapore.

Photographs from inside the plane revealed gashes in the overhead cabin panels, oxygen masks and panels hanging from the ceiling, and luggage scattered around. A passenger mentioned that some people’s heads had hit the lights above the seats, breaking the panels.

Singapore Airlines arranged a relief flight for 131 passengers and 12 crew members from Bangkok, which arrived in Singapore just before 5 a.m. The original flight had 211 passengers, including many Australians, British, and Singaporeans, and 18 crew members; however, injured passengers and their families stayed in Bangkok.

“On behalf of Singapore Airlines, I would like to express my deepest condolences to the family and loved ones of the deceased,” stated Singapore Airlines CEO Goh Choon Phong in a video message.

Singapore’s Transport Safety Investigation Bureau officers arrived in Bangkok on Tuesday night, according to Transport Minister Chee Hong Tat, who announced the news on Facebook.

Since the incident involves Boeing, a U.S. company that manufactures the 777-300ER aircraft, the U.S. National Transportation Safety Board (NTSB) is sending an accredited representative and four technical advisers to assist with the investigation, he added.

The plane encountered sudden extreme turbulence, Goh explained, prompting the pilot to declare a medical emergency and divert to Bangkok.

Aircraft tracking provider FlightRadar 24 indicated that at 0749 GMT, the flight experienced “a rapid change in vertical rate, consistent with a sudden turbulence event,” based on flight tracking data.

“There were thunderstorms, some severe, in the area at the time,” it noted.

Weather forecasting service AccuWeather stated on Tuesday that rapidly developing, explosive thunderstorms near the flight path of Flight 321 most likely contributed to the violent turbulence.

“Developing thunderstorms often have strong updrafts, zones of upward-moving air, that rise very rapidly, sometimes at more than 100 mph, leaving pilots with little time to react if it occurs directly in front of the plane,” explained Dan DePodwin, AccuWeather’s Senior Director of Forecasting Operations.

According to Singapore Airlines, the sudden turbulence occurred over the Irrawaddy Basin in Myanmar, about 10 hours into the flight.

“It is not uncommon for big thunderstorms to occur in the Bay of Bengal. There are always chances of encountering turbulence,” said an airline pilot who regularly flies to Singapore and Southeast Asia. The pilot requested anonymity as he is not authorized to speak to the media.

“We were about 30 miles off track navigating around the thunderstorms two days ago on the way to Singapore,” the pilot added.

The Bumpy Ride and Climate Change

From 2009 through 2018, the U.S. agency found that turbulence accounted for more than a third of reported airline accidents, most of which resulted in one or more serious injuries but no aircraft damage.

Turbulence, defined as a sudden, violent shift in airflow, is the most common cause of airline accidents involving injuries, according to a 2021 study by the National Transportation Safety Board (NTSB). 

Climate and aviation experts have noted that turbulence is likely to worsen due to climate change. 

There is strong evidence suggesting that climate change is increasing turbulence. Williams cited his own research indicating that severe clear-air turbulence in the North Atlantic has increased by 55 percent since 1979.

“Our latest future projections suggest a doubling or tripling of severe turbulence in the jet streams in the coming decades if the climate continues to change as expected,” he said.

Turbulence on flights can be caused by storms, mountains, and strong air currents called jet streams. However, the type of turbulence likely involved in today’s accident is known as clear-air turbulence, Williams explained.

“It can be difficult to avoid because it doesn’t show up on the weather radar in the flight deck. A detailed analysis of the meteorological circumstances and the specific type of turbulence that caused today’s fatality will take some time,” Williams added.

Other recent research published in Nature Climate Change indicates that climate change is distorting the jet stream, making the powerful winds in the upper atmosphere even faster.

“Based on these results and our current understanding, we expect record-breaking winds,” said Tiffany Shaw, a professor of geophysical sciences at the University of Chicago, in a news release last year.

“And it’s likely that these winds will lead to decreased flight times, increased clear-air turbulence, and a potential rise in severe weather occurrences.”

56 Incidents in Canada alone

According to data collected, 56 incidents involving turbulence-related injuries have been reported to the Transportation Safety Board of Canada since 2015.

The TSB reported that nine of these incidents involved serious injuries, thankfully no fatalities, while two of the incidents led to investigations. 

One was a 2015 Air Canada flight from China that injured 21 passengers, many of whom were not wearing seatbelts at the time, as noted in the TSB report. The other investigation involved a 2022 crash near Sioux Lookout, Ontario, where two people aboard a Cessna 208 Caravan aircraft were injured.

In 2019, 37 people on an Air Canada flight from Vancouver to Sydney were injured due to severe turbulence.

In the U.S., there have been 163 cases of serious turbulence injuries between 2009 and 2022, according to the Federal Aviation Administration. 

Of these, 129 cases involved flight crew, and only 34 involved passengers. The NTSB report noted that flight attendants are more frequently injured because they are often required to move around the cabin without the safety benefit of a seatbelt.

The last turbulence-related death on a commercial flight occurred in 2009, Williams said. The last death caused by clear-air turbulence on a commercial flight was in 1997, on a United Airlines flight from Tokyo to Honolulu.

Boeing 777 pilot Shem Malmquist, a visiting instructor at the Florida Institute of Technology and Fellow of the Royal Aeronautical Society, told media that turbulence-related injuries are becoming more common as climate change intensifies storm strength.

“With climate change, we have warmer oceans, which increases the probability for storms to manifest in ways that pilots have not been generally trained to detect,” he said.

Recently, incidents where people are injured by turbulence somewhere in the world occur every few weeks, he added.

“And I think we will see an increased number of them as the Earth’s average temperatures continue to rise. It’s just basic physics.”