Airlines are required by law to switch on the seatbelt sign during takeoff and landing of flights, but carriers have their own procedures to deal with mid-air turbulence.
A witness on the Singapore Airlines flight said numerous people who were not in their seatbelt were thrown around the cabin when the plane dipped, with many hitting their heads.
Sara Nelson, international president of the Association of Flight Attendants-CWA representing over 50,000 at 20 airlines, said CAT instances are on the rise and cannot be seen, stressing the importance of being buckled during flight.
“It is a matter of life and death,” Nelson said.
Turbulence-related airline accidents are the most common type of accident, a 2021 study by the US National Transportation Safety Board said.