What happened
On August 11, 2024, a Norwegian flight, NSZ2961, traveling from Rhodes to Helsinki, encountered severe turbulence during its descent. The aircraft, a Boeing 737-MAX 8 with registration SE-RYC, was descending through approximately 28,000 feet when it entered a highly unstable air mass. The turbulence caused the aircraft's vertical speed to fluctuate violently, ranging from a 200 feet per minute ascent to a 4,500 feet per minute descent, and resulted in the autopilot disconnecting.
At the time of the encounter, the flight crew had adjusted the heading to avoid a convective cell visible on the weather radar. While the senior cabin crew member (SCCM) and one crew member were able to secure themselves in their seats, two other crew members in the aft galley were caught unprepared. The intensity of the turbulence caused the two crew members to be thrown repeatedly into the air, striking the ceiling and aircraft structures before falling to the floor. One crew member sustained a neck injury, and the other suffered a head injury.
The investigation
The Finnish Safety Investigation Authority (OTKES) examined the flight's routing, weather briefing materials, and the crew's response to the weather radar data. The investigation looked into the cockpit's decision-making regarding the flight path change over the Baltic region and the effectiveness of the communication between the flight deck and the cabin crew. The investigation also reviewed the airline's safety management systems and previous reports of turbulence-related incidents within the company.
Findings
- The turbulence was classified as severe, characterized by rapid vertical accelerations and significant changes in flight path.
- The flight crew's decision to deviate from the original flight plan to avoid weather cells placed the aircraft into a region of more intense turbulence.
- There was a lack of active communication between the flight deck and the cabin crew regarding the changing weather conditions and the specific risks of the new route.
- The cabin crew members in the aft galley were unable to secure themselves before the onset of the severe vertical oscillations.