A Qatar Airways flight encountered turbulence over Turkey, injuring 12 passengers and crew. The flight from Doha to Dublin landed safely after the incident, causing people to “hit the roof” of the plane.
It comes just five days after the death of a British passenger and the injuries of 104 others after a Singapore Airlines flight hit sudden turbulence over Myanmar, causing it to dramatically lose altitude.
We know that turbulence is a common part of flying, but are some routes more sensitive and where is it worst?
What is turbulence?
Turbulence is felt when an aircraft flies through relatively disturbed air, which is responsible for “abrupt lateral and vertical jolts” during flight, according to Australia’s Civil Aviation Safety Authority. Turbulence is the leading cause of in-flight injuries for crew and passengers.
The agency defines eight types of turbulence, including thunderstorms, thermal waves, frontal waves and “mountain waves,” which can be divided into six categories of severity.
Where is turbulence most common?
Turbulence is generally expected over high mountains, oceans, the equator and at the intrusion of jet streams, said Dr Guido Carim Junior, head of Griffith Aviation at Griffith University. But clear air turbulence – normally caused by a very sudden change in wind direction – can occur anywhere, at any time.
“Beautifully complex factors work together to create turbulence,” the former pilot said, adding that even forest fires can cause turbulence. “Radar technology to detect turbulence is getting better, but despite all the instruments on board, we cannot accurately predict where and when turbulence will be.”
He has flown international routes over the Andes, where it is mandatory to turn on the seat belt sign when approaching the mountains, he said.
The Bay of Bengal is notoriously turbulent during the monsoon season, as is flying over the Alps – “but sometimes you don’t even notice it,” he said.
High humidity and temperatures tend to make turbulence stronger, so flying from London to New York City in the summer months will likely be bumpier than flying the same route in December, he said.
What are the most turbulent flight paths in the world?
Swedish turbulence forecasting site Turbli records turbulence using data from the US National Oceanic and Atmospheric Administration and the UK Met Office.
The most turbulent routes in 2023 were: Santiago, Chile to Santa Cruz, Bolivia; Almaty, Kazakhstan to Bishkek, Kyrgyzstan; Lanzhou, China to Chengdu, China; Centrair, Japan to Sendai, Japan; and Milan, Italy to Geneva, Switzerland. Milan to Zurich, Switzerland ranked tenth.
According to the site, the most turbulent countries to fly over in April were French Polynesia, Fiji, Pakistan, Namibia and Uruguay. The South Pacific was ranked as the most turbulent ocean flew over in the same month.
None recorded above an eddy dissipation rate (edr) of light turbulence of 20. Extreme turbulence occurs above 80edr.
Figures from the Australian Transport Safety Bureau (ATSB) show that there were 3,047 commercial aircraft incidents worldwide in 2023. Of these, 236 were caused by the weather.
So far in 2024, there have been 790 incidents involving commercial aircraft, 52 of which were due to weather conditions.
Is there a connection between the Qatar Airways and Singapore Airlines incidents?
If two planes are in the same area when they encounter turbulence, they could be affected by the same meteorology, says Milton Speer, a meteorologist and fellow at the University of Technology Sydney. But QF17 and SQ321 were thousands of kilometers apart when they were hit by intense turbulence.
Carim Junior said he had seen no obvious atmospheric or meteorological events linking the week’s two turbulences. He has spoken in recent days to pilots who have flown in both regions and was told they saw “nothing out of the ordinary.”
However, we know that the incidence of severe turbulence is increasing – by 55% between 1979 and 2020 – and climate change is thought to be a responsible factor.
How many turbulence incidents has Australia recorded?
Turbulence events only need to be reported to the ATSB if they affect the aircraft’s performance. In the 10 years between 2014 and 2023, no incidents involving serious passenger injuries were reported to the ATSB, a spokesperson confirmed.
A spokesperson for the Australian Federation of Air Pilots said passengers “would be well advised to wear a seat belt throughout the flight, regardless of seat belt signs”. Civil aviation regulations require all crew and passengers to wear seat belts in various circumstances, including when the aircraft is flying at less than 1,000 feet.