Accident to the Boeing 737 registered SE-RPE operated by Norwegian Air Sweden on 25/07/2021 en route to Nice
Turbulences en croisière, blessure grave d’un membre d’équipage de cabine, atterrissage d’urgence à destination
When the crew contacted the Milan ACC, 20 min before the occurrence, they were already engaged in storm cell avoidance manoeuvres. Other crews were also avoiding storm zones. This weather situation had been forecast. The meteorological file contained information about it.
The Milan ACC controllers regularly asked the crew to call back when they were able to head to BORDI waypoint, which is the point of tacit transfer between the Milan ACC and Nice approach.
The controllers were not able to see the meteorological information on their screens. They could not see the exact location of the storm zones that prevented the crew from heading to the requested waypoint for over 20 minutes.
After circumnavigating what they thought to be the last storm cell, the crew stated that they were able to head to BORDI waypoint. Approval was granted by the air traffic controller. On turning, they suddenly saw on the weather radar and had in sight, storm cloud developments embedded in the cloud mass, immediately behind the cell they had just circumnavigated.
It is possible that these storm clouds may have been hidden by the previous storm cell and that the onboard weather radar was unable to detect them earlier. It is also possible that they could not be detected by the onboard radar when the cell was in the radar’s detection beam. Lastly, it is possible that they may have been developing and appeared only shortly before on the aircraft’s path.
The crew were unable to avoid this cell and expected turbulence. They alerted the passengers. The aircraft passed through a zone of strong windshear and turbulence due to the presence of convective uplifts in a predominantly very strong southwesterly air flow.
Flight through this zone was short but very turbulent. Strong vertical and horizontal accelerations associated with windshear and variations in speed followed in succession in the space of around seven seconds.
It is very probable that it was at the beginning of this phase that a cabin crew member, who was busy securing equipment in the aft galley, was thrown to the ground. His foot then became trapped under an escape slide housing and his ankle broke during the vertical accelerations that followed.
The BEA issues 2 safety recommendations:
- Recommendation FRAN 2022-014 / Presentation of meteorological information on air control screens
The BEA recommends that:
- whereas the display of meteorological phenomena on air traffic control radar screens is likely to enable air traffic controllers to anticipate possible crew requests to modify flight paths and to implement, if needed, transfer strategies outside of the standard route;
- whereas this situation can be extrapolated to different air navigation service providers in Europe;
- whereas the recommendations already issued on the topic have not come to fruition;
EASA, in coordination with Eurocontrol:
1. conduct a global review of existing systems and those being developed that display near-real-time weather images on the radar screens of air traffic controllers, and their use by air navigation service providers as part of the flight information service, with the aim of facilitating meteorological avoidance strategies developed by flight crews,
2. on the basis of the above review and other available data, identify the system specifications, tools and working methods that would be most suitable for use by the European air navigation service providers in order to facilitate weather avoidance strategies developed by flight crews,
3. promote the implementation and use of such systems, tools and working methods by the European air navigation service providers in order to facilitate meteorological avoidance strategies developed by flight crews.
- Recommendation FRAN 2022-015 / Improvement of meteorological information provided on board aircraft
The BEA recommends that:
- whereas the effectiveness of the detection capability of onboard weather radars is variable;
- whereas weather radars do not always provide the flight crew with the information required to safely navigate through large areas of convective activity;
- whereas the provision of observed and forecast high-resolution meteorological information, such as images derived from satellites and ground weather radars, is likely to improve the crew’s situational awareness;
EASA promote systems and equipment providing advanced meteorological information on board aircraft that is updated in near real-time.
The recommendations are being processed
The status of the recommendations is available at SRIS2: click here
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Note: in accordance with the provisions of Article 17.3 of Regulation No 996/2010 of the European Parliament and of the Council of 20 October 2010 on the investigation and prevention of accidents and incidents in civil aviation, a safety recommendation in no case creates a presumption of fault or liability in an accident, serious incident or incident. The recipients of safety recommendations report to the issuing authority in charge of safety investigations, on the measures taken or being studied for their implementation, as provided for in Article 18 of the aforementioned regulation.