The Transportation Safety Board of Canada has taken to Twitter to remind flyers to buckle up throughout the duration of a flight.
It posted a seatbelt warning amid an ongoing investigation into severe turbulence on an Air Canada flight which sent 21 people to hospital.
The TSB posted a second reminder to keep belts on, citing a previous incident in 2011 when 16 passengers and crew were injured on an Air Canada flight.
The airline said the sealtbelt sign was on at the time but many passengers did not take heed of this.
The agency followed up the tweets with a statement, saying: "The Canadian aviation regulations require passengers to wear their seatbelts during taxi, takeoff, landing, when the seat belt sign is on and whenever directed to do so by crew members. It is recommended that passengers keep their seat belts fastened during the entire flight."
An aviation expert said the good safety record of air travel has given flyers a laissez-faire attitude to seatbelt instructions.
"It’s because we’ve made it such an incredibly safe mode of transportation that people’s awareness and their concern for their own safety is actually quite low," said Elaine Parker of Beyond Risk Management.
Air Canada said three passengers remain in hospital with injuries including serious chest and neck trauma.
