Vol commercial AD Stockholm/Arlanda (Suède) - AD Paris-Charles de Gaulle (95).
L’équipage conduit une approche RNP (LNAV/VNAV) pour la piste 27R à Paris-Charles de Gaulle. En raison d’une erreur de QNH (1011 au lieu de 1001), l’approche est effectuée sous le plan de descente. L’alarme MSAW est déclenchée. L’équipage interrompt l’approche à faible hauteur avant la piste, sans avoir acquis de références visuelles extérieures.
La seconde approche est également réalisée en dessous du plan de descente et donne lieu au déclenchement de l’alarme MSAW. Après acquisition du contact visuel avec la piste, l’équipage corrige la trajectoire avant d'atterrir sans autre incident.
The translation below is for information only:
Commercial transport flight from Stockholm/Arlanda AD (Sweden) to Paris-Charles de Gaulle AD
The crew conducted an RNP (LNAV/VNAV) approach to runway 27R at Paris-Charles de Gaulle. Due to a QNH error (1011 instead of 1001), the approach was flown below the glide path. The MSAW alarm was triggered. The crew aborted the approach at low height before the runway, without having acquired external visual references.
The second approach was also conducted below the glide path and the MSAW alarm was triggered. After acquiring visual contact with the runway, the crew corrected the path and landed without further incident.
The BEA issues 6 safety recommendations:
The BEA recommends:
• Whereas in the short time span of this event, an incorrect QNH was provided to two flight crews by one controller,
• Whereas in the short time span of this event, two controllers did not notice the readback of an incorrect QNH,
• Whereas the MSAW system, when available, can be considered as one of the last barriers to avoid CFIT,
• Whereas the MSAW phraseology was not used, and the QNH information was not repeated,
That Paris-Charles de Gaulle Air Traffic Services:
- Ensure without delay, that controllers are aware of the importance of the QNH for approaches using the baro-VNAV function, with respect to the risk CFIT [Recommendation FRAN-2022-005]
- Ensure without delay, that controllers are aware of the importance of checking that the information read back by flight crews is correct [Recommendation FRAN-2022-006]
- Ensure without delay, that controllers strictly use the standard phraseology in case of a MSAW, and provide the QNH information [Recommendation FRAN-2022-007]
- Implement without delay a procedure for controllers to mitigate the risk of an incorrect QNH being used by flight crews during approaches using the baro-VNAV function, possibly by repeating the QNH at an appropriate time during the approach. [Recommendation FRAN-2022-008]
The BEA recommends:
• Whereas there was a difference of 10 hPa between the QNH provided by the ATIS and the controller during the approach, which is higher than what might be expected from atmospheric pressure fluctuations, and was not noticed by the crew.
• Whereas the operational documentation of the airline does not highlight the importance of the QNH for approaches using the baro-VNAV function, with respect to the risk of CFIT,
• Whereas the airline operational procedures regarding approaches using the baroVNAV function are not robust against altimeter QNH setting errors affecting both altimeters,
that Airhub Airlines:
- Ensure without delay, that the flight crews are made aware of the importance of the QNH setting for approaches using the baro-VNAV function, with respect to the risk of CFIT [Recommendation FRAN-2022-009]
- Implement without delay, a procedure to mitigate the risks of an incorrect QNH setting affecting both altimeters during approaches using the baro-VNAV function, possibly by crosschecking the QNH with another source of information, in particular with the ATIS information when available or by asking the controller for confirmation of the QNH [Recommendation FRAN-2022-010]
The recommendations are being processed
The status of the recommendations is available at SRIS2: click here
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.