What happened
The flight was conducting a cruise phase operation when it encountered clear air turbulence at flight level 350. Prior to this event, the pilot had been aware of existing turbulent conditions in the area. In response to the forecasted weather, the seat belt sign was illuminated and instructions were issued for all flight attendants and passengers to take their seats.
When the turbulence struck, two of the three individuals injured during the incident were not seated as directed. The pilot noted that he had taken appropriate precautions by ensuring the warning signs were active and communicating with the cabin crew before the event began.
The investigation
The investigation focused on the circumstances surrounding the encounter with clear air turbulence. It was determined that while the pilot was aware of the weather conditions, the severity of the turbulence exceeded expectations. The primary finding related to passenger safety compliance during the incident.
Findings
Contributing factors included the unexpected intensity of the clear air turbulence and the failure of some passengers to remain seated despite warnings. The pilot's awareness of the weather did not prevent the injuries but demonstrates standard operational procedure for such conditions.
Safety message
Passengers must remain seated with seat belts fastened whenever the seat belt sign is illuminated, even if the aircraft appears to be flying smoothly. Turbulence can occur without warning and cause serious injury.