It was going to be a conventional flight. Long, quiet and with no more history than transporting 211 passengers from London to Singapore. It was not so. While flying over Burma, Singapore Airlines Flight 321 on Monday the 20th began to move very abruptly. So much so that dozens of passengers were injured, around thirty with serious injuries. In addition, a traveler died: the severe movements suffered by the Boeing 777 triggered cardiac arrest. Flight SQ321 ended up being diverted to the nearest airport, Bangkok, in order to attend to all those affected.
Strong turbulence that completely affected the aircraft’s lift would be responsible for the nightmare moments for passengers and crew. Turbulence has always been present in air navigation, although in recent times there is a feeling that it is more common. This leads us to ask ourselves some questions and look for the answers.
What is turbulence?
Aeronautical turbulence causes changes in the attitude and altitude of an airplane. It is caused by the variation in the direction and speed of the air in which it is flying. Crew members and passengers notice it directly in the form of shaking or shaking and, if it is not excessive, the pilots in command do not have to intervene to correct the situation. It is the autopilot itself that balances, corrects and compensates the flight attitude of the device.
Although they may be annoying or even disconcerting after a few hours of straight and level flight, it must be understood that turbulence is part of air travel. They could be compared to a bumpy road that makes a land trip not so pleasant, or that swell that turns a sea crossing into a bumpy experience. In any case, helped by technology and their own experience, pilots are used to dealing with them.
What is clear air turbulence?
Although an exhaustive investigation of the flight parameters and meteorological conditions in the area will determine the causes of the Singapore 777 incident, what happened would indicate that the aircraft encountered a CAT, acronym for Clear Air Turbulence, translated as turbulence. in clear air. According to the definition of the US Federal Aviation Administration, a CAT is the movement of air created by collisions of disparate air currents due to atmospheric pressure, jet streams or air around mountains. It is also caused by the meeting of cold and warm weather fronts or thunderstorms. The problem with this type of turbulence is that it is difficult to avoid because it does not appear on the flight deck’s weather radar.
Is it true that there is more turbulence now?
“I have been flying on intercontinental lines for 17 years and although these are personal sensations, flights in recent years have had more turbulence than before,” Rosa María, long-haul cabin crew on Airbus aircraft, told La Vanguardia. Aboard these, she crosses the Atlantic an average of eight to nine times a month. The feeling of this flight attendant is corroborated by Sergio Hoyas, professor of Aerospace Engineering at the Polytechnic University of Valencia. Asked by EFE after the SQ321 incident, this engineer warns that turbulence or storms are getting worse, especially in the North Atlantic, due to climate change, which directly affects air transport.
Hoyas knows the situation first-hand, not because he is a crew member, but because he is part of an international team that has developed new techniques that allow turbulence and its impact to be studied. Another professor, this time English, shares that opinion. Paul D. Williams, professor of atmospheric sciences at the University of Reading, published a study in 2019 in the scientific journal Nature. This shows that since 1979, the amount of wind shear in the jet stream has increased by 55%. The cause that he indicates in this study is that, at higher altitudes, which is where airplanes fly, climate change is altering temperature patterns, which creates more situations in which aircraft can be affected by this phenomenon and will go in increase.
What can be done?
From the cockpit of her regional reactor, Commander Lourdes confirms to La Vanguardia the feeling that more and more phenomena are occurring that affect flight. “Flying is safe. I tell everyone this over and over again, although what I also notice is that some exceptional situations are no longer so exceptional in recent years,” she says. “Increasingly advanced detection systems and technologies make air transport better and better, although progress should be made in creating a system that warns us about things like CAT.”
For her part, from the passenger cabin, Rosa, the crew member, remembers something that seems like common sense after seeing what happened in London-Singapore: “We always recommend that passengers wear their seat belts. At all times, even when the light signal is off. Strong turbulence does not warn and serious injuries are suffered by those who were standing or sitting without securing themselves to the seat.”
What risks do they entail?
The images of hanging oxygen masks, open trunks, some fallen panels, as well as food and drinks scattered throughout the cabin of the Singapore Airlines plane have gone around the world, although they must be put in context: the interior materials of the plane, as the panels for their beautification are light to avoid excess weight. Structural parts such as the fuselage, floor or seats have not been affected, as they have been designed to withstand adverse circumstances. It is known that turbulence will increase, although the planes are prepared to face it. Only in extreme and very, very strange situations would they suffer structural damage.
