What happened
On 23 August 2010, a Boeing 737-600, registration LN-RPH, was performing a commercial passenger flight on approach to London Heathrow Airport. While at flight level 110, the aircraft encountered weather-related turbulence. Although the weather radar showed several cells, the aircraft had appeared to clear a specific cell before experiencing a brief period of more intense turbulence.
At the time of the encounter, the cabin seat belt sign had been illuminated, and the pilots had made a pre-landing announcement regarding the weather. However, the cabin crew were in the process of securing the cabin for landing and were not restrained. One crew member, seated in the rear galley, was thrown into the air and landed back on her seat, resulting in serious injuries to her back. Another crew member was also thrown into the air but remained uninjured. The remaining crew members were unaffected by the movement.
The investigation
Investigators examined the circumstances surrounding the crew's lack of restraint and the communication of weather updates. The operator's internal investigation revealed that the crew members were largely unaware of the specific weather-related comments made in the pilot's announcement.
Further review of the operator's safety records identified a pattern of similar incidents where cabin crew sustained injuries during turbulence while preparing for landing. In one previous instance, two crew members suffered bone fractures. The investigation also looked into the timing of seat belt sign illumination. Under the operator's procedures, the sign was intended to illuminate 10 minutes before landing, but the investigation noted that the crew might misinterpret the sign's meaning without explicit clarification from the flight deck regarding whether the cabin or the entire crew was secure.
Findings
- The aircraft encountered unexpected turbulence after appearing to have cleared a weather cell.
- The cabin crew were not restrained at the moment of the turbulence encounter because they were actively performing landing preparations.
- Inadequate communication between the flight deck and cabin crew regarding the specific nature of the turbulence and the requirement for crew restraint contributed to the injury.
- The existing procedure for seat belt sign illumination did not provide sufficient notice for crew to secure themselves during unexpected atmospheric changes.