Accident to the Beech - G58 registered F-GNSG on 25/08/2021 at Chalon-Champforgeuil (Saône-et-Loire)

Cat. 3 investigation report: report concerning an occurrence with limited consequences, based on one or more statements not independently validated by the BEA.

This is a courtesy translation by the BEA of the Final Report on the Safety Investigation published in December 2021. As accurate as the translation may be, the original text in French is the work of reference.

Note: The following information is principally based on statements made by the persons on board. This information has not been independently validated by the BEA.

1 - HISTORY OF THE FLIGHT

The student pilot and the instructor, accompanied by two other student pilots, took off from paved runway 35 at Chalon-sur-Saône aerodrome[1] at around 12:30 for an IFR instruction flight. The instructor had planned a series of local exercises before returning to their base at Saint-Yan under VFR. After a first one-engine inoperative (OEI) exercise in climb, the student pilot started an NDB procedure during which a second OEI exercise was started on the final segment. The exercise involved aborting the NDB approach according to the prescribed flight path, then joining the holding pattern centred on FLH35 before performing a RNP 35 approach, still carried out in "N-1". At the end of this approach, a touch-and-go was planned before returning to Saint-Yan. The aeroplane touched down with the landing gear retracted, slid and came to rest on the runway.

2 - ADDITIONAL INFORMATION
2.1 Meteorological information

The weather conditions observed at the accident site at 13:00 were as follows: north-north-east wind of 8 kt, scattered clouds, temperature 22 °C, dew point temperature 13 °C, QNH 1,018.

2.2 Chalon-Champforgeuil RNP 35 procedure

The Chalon-Champforgeuil RNP 35 approach is characterized by a heading modification of 30° to the right on passing the FAF, 6.1 NM from the runway threshold.

2.3 Operator’s procedures

During "N-1" approaches, the landing gear should be extended when passing the FAF.
The extension of the landing gear should be checked on final during the "Before landing check-list" and then on short final by means of a "Landing call out" which was introduced in the operator's procedures after a similar event had occurred a few months earlier.

2.4 Summary of the statements

The instructor (around 4,000 flight hours) took off from Saint-Yan at about 09:00 with three student pilots as part of IRME training in the scope of an introductory   programme. Two student pilots flew successively the Saint-Yan - Dôle and Dôle - Chalon-sur-Saône segments during which they carried out the same program of several OEI exercises. These two student pilots then sat in the back on departure from Chalon-sur-Saône, leaving the controls to the third student pilot (approximately 220 flight hours).
On passing the FAF during the RNP 35 procedure in the “N-1” engine configuration, the student pilot focused on starting the descent and changing the heading and forgot to extend the landing gear. During the final approach, she focused on holding the centreline, approach slope and airspeed and forgot to complete the “Before landing checklist”. On short final, she looked at the landing gear control while announcing the "Gear" item of the "Landing call out". However, she did not perceive that the lights were off. As soon as the aeroplane touched down, she understood the situation and applied full power to both engines. This reaction did not allow the aeroplane to regain height and it slid down the runway with the power controls pushed forward.
On passing the FAF, the instructor focused on the management of the flight path; he did not detect the non-extension of the landing gear and the omission to perform the “Before landing checklist”. He did not hear the student pilot call out the "Landing call out" items. On short final, his attention was mainly focused on touchdown in order to reconfigure the aeroplane as quickly as possible in order to take-off again[2].
During the final approach, the student pilot in the right rear seat had a doubt about the extension of the landing gear. He tried to alert the instructor without being fully explicit, fearing that he would disturb the student pilot at the controls or even compromise what could have been an educational approach by the instructor. The instructor understood that the remark related to the rudder trim that the student pilot flying was just about to adjust.
The "landing gear up" alarm sounded regularly and for a long period of time during the three flights due to the reduction of power of one engine below the triggering threshold during the various exercises carried out in "N-1"[3].
It appeared from the statements that the flight was carried out in the context of a training program which had been perceived by the student pilots as dense and tiring for several days.
Furthermore, the work in progress at Saint-Yan lengthened taxiing times and prevented local IFR procedure training from being programmed. This situation made it necessary to start the briefing earlier in the morning (07:30 on the day of the accident) and, more generally, to manage time more tightly during and between flights. Usually when this type of training is performed from Saint-Yan, the student pilot scheduled to make the third flight is not taken on board until the second flight, in order to limit his fatigue. Lastly, as this situation led to training being programmed on uncontrolled aerodromes[4], it increased the workload due to the attention required to avoid collisions.
The student pilot in command had made good progress. The instructor believed that this may have contributed to reducing his alertness during this third flight of the morning.

3 - LESSONS LEARNED AND ACTIONS TAKEN AFTER THE ACCIDENT

Following this accident, the operator planned to explore the possibility of operating in a fictitious "N-1" mode, to avoid a situation where the landing gear alarm continuously sounds. The scenario at the time of the accident was standard, consisting of an "N-1" approach followed by a missed approach, a holding pattern then another "N-1" approach. The crew may become used to a prolonged activation of the alarm that is not conducive to the detection of an actual failure to extend the landing gear. Furthermore, according to its volume, the background noise thus produced is likely to affect the level of fatigue and the attention of the crew members, in a phase of flight where there is already a high workload and which uses a lot of attention resources.
In addition to these phenomena, during the "N-1" approach, the landing gear and flap extensions are delayed which deprives the crew of some kind of automatism in the execution of the before landing actions. In the case of the approach during which the accident occurred, the change of the heading on passing the FAF was also likely to increase the workload. The ability to prevent and then detect the omission to extend the landing gear in such a situation depends in part on the attention resources available when this situation occurs. The high workload, the duration of the session as well as the additional constraints arising from the change of location for the training flights are all factors that may have previously depleted the attention resources of the instructor and/or the student pilot. In relation to this analysis, the operator planned to:

- Raise crew awareness so they take such factors into account in the context of “Threat and Error Management” (TEM), during the flight preparation.
- Investigate the possibility of implementing a restriction on the use of "short runways" for "N-1" exercises in order to eliminate the extra workload caused by this situation.

In addition, the operator planned to:

- Analyse the feedback regarding the "Landing call out" procedure, introduced shortly before this accident, in order to improve, if possible, its applicability.
- Remind crews of the operational criteria and procedures associated with stabilization on final approach.

Lastly, the operator planned to alert the crews to the need to determine how safety information should be transmitted between passengers and the instructor. The goal was to promote effective intervention by passengers as part of their role in flight safety.