Singapore Airlines Ltd has introduced tighter cabin restrictions when aircraft hit turbulence, after one passenger died and scores were injured on a flight from London earlier this week.  

The airline said on Friday it’s taking a “more cautious approach” to managing turbulence, after Flight SQ321 suddenly lost altitude on Tuesday and was forced to make an emergency landing in Bangkok. One man died, and dozens of passengers remain in Thai hospitals suffering serious trauma, including spinal-cord damage and head injuries.

In-flight meal service will be halted when the seatbelt sign is switched on, in addition to the suspension of hot drinks, the airline said in a statement. Crew members will also return to their seats and strap themselves in. 

Singapore Air “will continue to review our processes” to prioritise the safety of crew and passengers, it said.

The policy revision stops short of requiring all passengers to wear seatbelts throughout the trip, irrespective of flying conditions at the time. Airlines typically advise travellers to do this, and only instruct them to sit down and buckle up during unstable weather. 

The injuries sustained by passengers underscore the huge vertical forces that overwhelm anyone who isn’t strapped in when an aircraft suddenly plummets. On Flight SQ321, people were catapulted into the cabin roof, and personal belongings and items from the breakfast service were hurled around the aircraft.

Some 22 passengers have received treatment for spinal damage, and six have suffered skull and brain injuries, the Samitivej Srinakarin Hospital said on Thursday. Twenty were in intensive care, while 17 have undergone surgery. In the immediate aftermath of the flight, more than 100 people required medical care in Bangkok.

Despite the fatality and the injury toll, airlines are unlikely to mandate seatbelts at all times on every flight, said Ron Bartsch, an ex-safety chief at Qantas Airways Ltd. who formerly managed airline operations for Australia’s civil aviation regulator. Death and serious injury from severe turbulence are so rare that it’s not worth introducing permanent restrictions that may put off some passengers, he said.

“I can’t remember the last fatality associated with turbulence. It’s not as though it’s a common occurrence,” said Bartsch, the founder of Sydney-based Avlaw Aviation Consulting Pty Ltd and the author of books including International Aviation Law: A Practical Guide. “People don’t like to be told to have their seatbelt fastened as a requirement and return to their seats. I don’t expect any major changes to the way airlines operate.”

In its statement, Singapore Air said its pilots and cabin crew are aware of the hazards associated with turbulence. The cabin crew is already trained to secure all loose items and equipment to minimise the risk of injury in these situations.

Turbulence can occur when a plane hits a strong air current that pushes or pulls the airframe. The phenomenon can be caused by pockets of hot air or powerful weather systems. At higher altitudes, aircraft might encounter hard-to-identify clear air turbulence caused by air masses with differing velocities.

The forces can fling passengers around so hard that it can be as dangerous as falling headfirst off a ladder or diving into a shallow concrete swimming pool, according to Rohan Laging, the deputy director of emergency services at Melbourne hospital group Alfred Health. 

  - Bloomberg