What happened
On 18 October 2014, a Singapore Airlines Airbus A380, registration 9V-SKJ, was performing a scheduled passenger flight from Singapore Changi Airport to Mumbai. During the descent from Flight Level 380 to FL150, the flight crew identified a patch of cumulonimbus clouds on the weather radar and proactively activated the fasten seat belt sign. To maintain safety margins, the crew requested a heading change to avoid the convective weather.
While the aircraft was approximately 62nm southeast of Mumbai, it encountered a period of intense vibrations lasting over two minutes. During this window, the aircraft experienced severe turbulence that lasted approximately two seconds. At the time of the impact, the cabin crew were moving through the aisles to secure the cabin following a recent announcement to sit down. The sudden vertical acceleration caused several passengers and crew members to be thrown toward the cabin ceiling.
The investigation
The investigation, conducted by the Air Accident Investigation Bureau of Singapore, focused on the nature of the turbulence and the subsequent injuries. Investigators analyzed flight recorder data, which showed a maximum vertical acceleration of +1.77G/-0.42G. The study also examined the availability of handholds in the passenger cabin and the communication protocols used by the flight crew following the event.
Findings
- The primary cause of the event was an encounter with clear air turbulence, as no clouds or significant weather cells were visible on the radar at the exact moment of the impact.
- The incident resulted in four serious injuries, including two passengers and two cabin crew members. Other passengers sustained minor injuries, many of whom were in the lavatories at the time of the event.
- While galley areas contained handles for stability, the passenger aisles lacked dedicated handrails, as the aircraft design relies on seat backs for stability in moderate turbulence.
- The flight crew did not immediately notify Air Traffic Control (ATC) of the injuries, primarily to avoid potential landing delays and because the aircraft was already on final approach.
Safety action
Following the investigation, the operator has reminded its flight crews of the necessity to inform ATC of any injuries or emergency situations encountered during flight.