What happened
On 13 November 2024, a Boeing 737 departed Sydney, New South Wales on a scheduled passenger flight to Brisbane, Queensland.
Just prior to descent, the flight crew, aware of potential upcoming turbulence, turned the seatbelt sign on, and made a standard announcement for all passengers to return to their seats and to fasten their seatbelts.
Around 4–5 minutes after the seatbelt sign was turned on, as the aircraft passed FL330,[1] the aircraft encountered severe turbulence for approximately 45–60 seconds.
One passenger, who was already in the toilet prior to the seatbelt sign being turned on, did not return to their seat before the turbulence encounter. Another passenger, with a small child, ignored the seatbelt sign and cabin crew requests to be seated and proceeded with the child to the second toilet where they remained during the turbulence encounter. The door to this toilet was damaged during the turbulence, likely from passenger impact, and was unable to be opened. An off-duty pilot assisted removing the door to access the 2 passengers inside. All 3 passengers sustained minor injuries and were provided with first aid by cabin crew.
The flight crew declared a medical PAN PAN[2] to air traffic control and the aircraft landed in Brisbane without further incident. Ambulance staff treated the injured passengers at the gate.
Context
Turbulence
Turbulence is caused by the irregular movement of air and often cannot be seen and is responsible for the abrupt sideways and vertical jolts that passengers often experience during flights.
Cabin safety
While turbulence is normal and occurs frequently, severe turbulence can cause passengers and cabin crew who are not wearing their seatbelts to be thrown around without warning. About 20 in‑flight turbulence injuries are reported in Australia each year. Some of these injuries are serious and have resulted in broken bones and head injuries.
Almost all turbulence injuries involve people who are not properly seated and do not have their seatbelt fastened. A securely fastened seatbelt is the best defence against injuries. It should be fastened low and tight around the waist.
Safety message
When the seatbelt sign is on, passengers are required by law to have their seatbelt fastened for their own safety. Even when the seatbelt sign is off, passengers should continue to keep their seatbelt fastened, as pilots or cabin crew do not always have enough time to warn passengers to fasten their seatbelts before turbulence hits.
Cabin crew are trained to ensure passengers are safe at all times, and are aware of the dangers of in-flight turbulence. It is for this reason that passengers should follow any requests by cabin crew – including fastening seatbelts, securing carry-on baggage, or returning to seats when asked.
About this report
Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.
[1] Flight Level: at altitudes above 10,000 ft, an aircraft’s height above mean sea level is referred to as a flight level (FL). FL 330 equates to 33,000 ft.
[2] PAN PAN: an internationally recognised radio call announcing an urgency condition which concerns the safety of an aircraft or its occupants but where the flight crew does not require immediate assistance