What is clear air turbulence and how did it affect the Singapore Airlines flight from London?

A passenger has died on board Singapore Airlines flight SQ321 after the flight from London Heathrow to Singapore suffered severe turbulence.

In addition to the death, around 50 of the 211 passengers and 18 crew on board were injured, it was reported.

Singapore Airlines “offers its deepest condolences to the family of the deceased” and says it is working with Thai authorities to provide necessary medical assistance.

What else do we know about this tragedy?

Singapore Airlines flight SQ321, non-stop from London Heathrow to Singapore, took off at 10:37pm on Monday night for a routine flight to Southeast Asia. It appears that the Boeing 777-300 encountered clear air turbulence over the Bay of Bengal, south of the southern tip of Myanmar, just before 9am British time. At 9.07am UK time, a turn towards Bangkok and a rapid descent from cruising altitude began.

The plane landed in the Thai capital at 9:45 a.m.

By the time the plane encountered clear-air turbulence, there were about 90 minutes left in the planned flight time to Singapore. It is likely that the crew had moved around the cabin preparing breakfast, along with several passengers.

The Boeing 777-300 was delivered to Singapore Airlines in February 2008.

It is likely to remain grounded until engineers are satisfied it has not suffered structural damage.

What is Singapore Airlines’ safety record?

Excellent. The only Singapore Airlines accident that caused fatalities was that of a Boeing 747 jumbo jet that took off from Taipei in 2000. The pilots mistakenly attempted to take off from a closed runway and collided with construction equipment. Of the 179 passengers and crew on board, 83 died and 96 survived.

What is clear air turbulence?

The US National Weather Service says: “Turbulence is caused by abrupt, irregular air movements that create rapid, sharp updrafts and downdrafts. These updrafts and downdrafts occur in combinations and move aircraft unexpectedly.”

The US Federal Aviation Administration (FAA) defines clear-air turbulence as “sudden, severe turbulence that occurs in cloudless regions and causes violent buffeting of aircraft… CAT is especially problematic because it is often found unexpectedly and often without visual cues to warn pilots of danger. “

Is it unusual for a death to occur as a result of turbulence?

Yes, very strange. But injuries on board an airplane can be alarming. In an article for the British Airline Pilots Association (Balpa), former pilot and flight safety specialist Steve Landells says: “The injuries we see tend to occur when people are not restrained. This may be because turbulence occurs without warning, but I also see many people injured because they do not obey instructions to “fasten your seat belt.”

Cabin crew are particularly vulnerable.

How often does this type of incident occur?

One study suggests that airplanes encounter severe turbulence in clear air at least 790 times a year, which occurs once every 11 hours. But climate researchers say the incidence at a typical point over the North Atlantic increased by 55 percent between 1979 and 2020.

According to Paul Williams, Professor of Atmospheric Sciences at the Department of Meteorology at the University of Reading, a doubling of carbon dioxide (CO2) levels in the atmosphere would increase dangerous turbulence on commercial flights, making them two or even three times more common. which is how it is today, with five serious cases a day on average.

How does climate change contribute to clean air turbulence?

Emerging evidence suggests that temperature changes caused by the climate crisis are altering the flow of air currents in the atmosphere due to changes in wind speed and direction.

“Climate change is going to have many effects on aviation. We expect the atmosphere to become more turbulent. So there could possibly be double or triple the amount of turbulence in flights in the coming decades,” Paul Williams, professor of atmospheric sciences at the University of Reading, previously said. The independent.

“We know that the jet stream at cruise altitudes has become 15 percent more sheared over the North Atlantic since satellites began observing it in the 1970s,” Dr. Williams said.

A 2017 study published in the journal Advances in atmospheric sciencesanalyzed the impact of stronger wind shear (an abrupt change in wind speed or direction over a short distance that is a major cause of turbulence) on winter transatlantic flights.

It found that doubling global CO2 levels will increase the average amount of severe CAT at 39,000 feet by 149 percent, meaning airline passengers will have a bumpier ride in the future if emissions continue unabated.

What can passengers do to limit the danger?

The most basic precaution is to keep the seat belt at least loose when seated.

Steve Landells of Balpa says: “Don’t be tempted to get up when the captain has told you to put your seat belt on; We are always talking to the pilots of the planes ahead of us and, even if everything is calm when we put the signals, we can know that there will be bumps soon.”

If the pilot tells the cabin crew to fasten their seat belts, the turbulence is most likely severe.

What does clear air turbulence feel like?

This is a sudden and very frightening bump in flight, possibly with a spin involved, or a longer series of awkward vertical movements. The sensation has been compared to a theme park attraction where you keep going around and around with no way to get off.

Can turbulence bring down a plane?

Not a modern plane like the Boeing 777. As with this tragedy, it is the events inside the cockpit that are most dangerous.