What happened
On 6 September 2024, a Scoot flight operating a Boeing B787-9, registration 9V-OJD, was descending toward Guangzhou, China, when it struck a pocket of severe turbulence. The aircraft was transitioning through 18,700 feet near waypoint TAMOT within the Hong Kong Flight Information Region.
Prior to the event, the flight crew had observed no significant weather on the onboard radar and had opted to turn off the fasten-seat-lubricant signs to allow passengers to use the lavatories. However, the sudden encounter caused rapid changes in vertical acceleration, with forces peaking at +2.86G. The turbulence was violent enough to trigger the aircraft's stick shaker.
Following the impact, the cabin crew discovered that one passenger had sustained a fractured spinal bone and one cabin crew member had suffered fractured feet. Several other crew members also reported minor injuries. The aircraft landed safely in Guangzhou without further incident.
The investigation
Investigators examined flight data from the digital flight data recorder and reviewed meteorological information. While Super Typhoon Yagi was active in the region, it was located approximately 195nm away and was not considered a direct cause of the event.
Analysis of ground-based weather radar revealed that a convective cell had intensified about 6.6nm south of the aircraft's position shortly before the encounter. Because this weather system was located behind the aircraft, it was not visible on the plane's onboard weather radar, which is unable to detect precipitation behind the aircraft's current position.
Findings
- The turbulence was likely caused by a convective cell that had developed to the rear of the aircraft.
- The onboard weather radar did not display the hazard because the activity was positioned behind the aircraft's flight path.
- The flight crew had not yet reached the 10,000-foot threshold where fasten-seat-belt signs are typically required to be active, and no immediate weather threats were visible on their instruments.
Safety action
In response to the incident, the operator has implemented several new safety measures:
- Revised guidelines now require fasten-seat-belt signs to remain on from takeoff to the top of climb, and from the top of descent until landing when operating in typhoon-affected areas.
- New instructions mandate that flight and cabin crews make public announcements emphasizing the importance of remaining seated with seat belts fastened, even when signs are off.
- The airline has integrated the IATA Turbulence Aware app into electronic flight bags to provide crews with more detailed real-time turbulence reports.