Accident to the Embraer EMB500 registered 9H-FAM operated by Luxwing on 08/02/2021 at Paris-Le Bourget
Décrochage en courte finale par conditions givrantes,atterrissage dur, rupture des trains principaux et du trainavant, incendie, sortie latérale de piste
Before starting the descent to destination, the crew listened to the Le Bourget airport ATIS which indicated the presence of severe icing between 3,000 and 5,000 ft. They carried out the approach applying the manufacturer’s normal procedure for an approach in non-icing conditions, the approach speed selected by the crew (Vref 97 kt) was thus 22 kt below the approach speed in icing conditions and was, according to the manufacturer, close to the stall speed in the event of ice contamination.
At 3,000 ft, the crew activated the wing and stabilizer de-ice system for a period of 21 s which corresponded to a complete de-ice cycle. The crew indicated that they observed through the cockpit window that the ice which had built up on wing leading edges had broken up. They then deactivated the de-ice system and did not active it again. This decision was solely based on the visual observation of the wing leading edges.
The presence of ice on the wing and stabilizer leading edges observed after the accident shows that ice built up on the aeroplane on final. The following hypotheses can thus be made:
- Either the light and clouds did not allow the crew to determine the actual degree of contamination of the wings.
- Or the shapes and thickness of this built-up ice were visible from the cockpit and in this case:
- after deactivating the de-ice system, the crew no longer actively monitored the leading edges to ensure that there was no formation of ice or,
- the crew observed this build-up of ice but underestimated the consequences of this.
In the conditions of the day, the aeroplane’s weight and the configuration selected by the crew, compliance with the manufacturer’s procedure for an approach in icing conditions would have meant that the aeroplane would not be able to land at Le Bourget airport. This was because firstly, in the event of a go-around with one engine inoperative, the aeroplane’s climb rate was not sufficient to safely clear obstacles. Secondly, the landing distance available was less than the landing distance required by the aeroplane. The crew told the BEA that they were aware of these limitations even before taking off and that they knew that if they had to continuously activate the de-ice system until landing, they would have to divert.
Given that it was impossible to meet the operational constraints by strictly complying with the procedure, the strategy chosen by the crew was to carry out the landing according to the manufacturer's procedures for an approach and landing in non-icing conditions while ensuring that ice had not built up on the aeroplane. The captain explained that this was a standard adaptation of the procedure.
The deactivation of the de-ice system had the following consequences:
- The ice that may have built up on the leading edge of the horizontal stabilizer may not have been completely broken up.
- Ice built up again on the aeroplane at the end of the approach.
- The Stall Warning Protection System (SWPS) was not configured to cut in effectively in the icing conditions of the accident: the speed tape displayed on the PFD was not configured to alert the crew that they were flying at a speed close to the stall speed and the aural stall warning and the Stick Pusher protection were not configured to activate at the appropriate angles of attack.
Just before the impact, the aeroplane was flying in low speed and high angle-of-attack envelopes where the aircraft was likely to stall in case of ice contamination of its structure. The recorded flight data did not enable the exact degree of contamination to be determined, but the presence of ice on the leading edges of the wings and horizontal stabilizer observed after the accident confirmed that ice had built up on the aeroplane.
The BEA issues 3 safety recommendations:
- Recommendation FRAN 2023-001 / Improvement in the crews situational awareness when operating in icing conditions:
The BEA recommends that:
- whereas the performance penalties in icing conditions for Embraer EMB-500 Phenom 100 types of aircraft encourage crews to apply a divergent and potentially dangerous interpretation of the manufacturer's procedures for the approach and landing in icing conditions;
- whereas Embraer has an optional system for the EMB-500 Phenom 100 equipped with the G1000 avionics suite, available to operators, which improves crew situational awareness during flights in icing conditions;
- whereas this system is installed in series production on other versions of the EMB-500 Phenom 100 equipped with the G3000 avionics suite;whereas this system, by providing objective information on the presence of icing conditions, is likely to assist in deciding on the need for full and strict application of the flight in icing conditions procedures;
- whereas a small proportion of Embraer EMB-500 Phenom 100s in service, equipped with the G1000 avionics suite, have this detector;
the ANAC in coordination with Embraer, assess the improvement to safety that would be obtained by installing an ice detector on all EMB-500 Phenom 100 aircraft and the need to impose this modification on all Phenom 100 aircraft authorised for flight in icing conditions.
- Recommendation FRAN 2023-002 / Consideration given by operators to operational constraints related to operations in icing conditions:
The BEA recommends that:
- whereas the large differences between the operational performance in icing and non-icing conditions of certain jet aircraft covered by CS-23 certification rules, such as the one involved in the accident;
- whereas certain operators do not systematically take into account the operational constraints arising from the performance of the aeroplanes they operate in icing conditions;
EASA, in coordination with the national oversight authorities, in the interest of promoting safety, make operators aware of the need to give better consideration in flight planning to
the landing performance of aircraft which have significant differences in performance in icing and non-icing conditions.
- Recommendation FRAN 2023-003 / Consideration given to operational constraints during certification process:
The BEA recommends that:
EASA consider revising the certification criteria (by applying special conditions, for example) when the differences between an aircraft’s performance in icing and non-icing conditions lead to operational constraints that are difficult for crews to manage.
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.