What happened
During a descent into Brisbane, the flight crew initiated cabin preparations earlier than usual due to known weather conditions en route. While the graphical area forecast had suggested the possibility of moderate to severe turbulence, the captain did not observe any weather radar returns or pilot reports confirming such conditions.
Approximately five to six minutes after starting cabin preparations, the aircraft entered stratiform cloud. The captain contacted the customer service manager to check on the progress of the cabin crew to assist with the timing of the seatbelt sign. However, the captain did not relay any weather-related information during this exchange. Shortly after, the seatbelt sign was illuminated alongside a standard seatbelt public announcement. Although the captain noted an approaching cumulus cloud, the lack of radar indications led to a determination that it did not pose an immediate hazard, and no specific turbulence warning was issued.
At the time the seatbelt sign was activated, the cabin crew were performing duties that required them to be unrestrained. Because the severe turbulence encounter occurred less than one minute after the seatbelt sign was illuminated, the crew members did not have sufficient time to secure themselves. This resulted in three cabin crew members being unrestrained during the event, leading to three injuries.
The investigation
The investigation examined the communication between the flight deck and the cabin and the subsequent management of the cabin following the event. It was found that the crew members were performing duties in the lavatories and galley when the turbulence hit. One crew member was found lying on the floor of the aft galley, unable to move due to their injury.
Following the encounter, the focus of the remaining crew and assisting passengers shifted to providing first aid to the injured member. This preoccupation with medical assistance meant that the CSM and L2P did not return to their assigned seats, despite instructions from the captain. This disruption prevented the completion of the required callback and silent review procedures prior to landing. Additionally, the investigation noted that one crew member with an undiagnosed concussion continued to operate subsequent flights, as there was no procedure in place to ensure fitness for duty was assessed following such an injury.
Findings
- The captain did not communicate the potential for turbulence to the cabin crew, largely because the severity of the turbulence was not anticipated.
- Three cabin crew members were unrestrained during the encounter, resulting in three injuries.
- The focus on administering first aid to the injured crew member led to other crew and passengers remaining unrestrained for landing, which could have compromised an emergency evacuation.
- Existing procedures did not require the flight crew to receive positive confirmation that the cabin was secure for landing.