Note: The following information is principally based on the instructor and student pilot statements. This information has not been independently validated by the BEA.
This is a courtesy translation by the BEA of the Final Report on the Safety Investigation published in September 2020. As accurate as the translation may be, the original text in French is the work of reference.
1 - HISTORY OF THE FLIGHT
The instructor and the student pilot took off from Brest Bretagne aerodrome for a local instruction flight.
While the aeroplane was established on final for runway 25L, the controller gave the crew clearance to land. He specified that the wind was from 170°, 26 kt, gusting to 37 kt.
At the end of the flare, the aeroplane was destabilized by a gust that caused it to roll to the right. The instructor then took control and initiated a go-around. The tip of the right wing touched the runway. The pilot then abandoned the missed approach manoeuvre and reduced the throttle. The plane slewed to the right and went off the runway.
After the runway veer-off onto the grass, the left main gear was torn off and the DA40 ended its run about 100 m from the right edge of the runway. The left wing, the nose wheel and the three blades of the propeller were also damaged.
2 - ADDITIONAL INFORMATION
2.1 Weather information
The wind indicated by the controller is averaged over two minutes. For gusts, it is the maximum speed over the last ten minutes that is considered.
At 12:02:54, i.e. one minute before landing, the controller transmitted the following information to the crew:
- Wind 170°, 26 kt, gusts to 37 kt.
The data transmitted by Météo France for Brest Bretagne aerodrome show that at 12:04, during the landing of F-HPYB, the average wind over one minute was from 160° and 39.1 kt.
2.2 Information from flight manual
The maximum demonstrated crosswind component for landing is 20 kt, including gusts. This maximum component was used for certification. However, it does not appear in the "Limitations" section of the flight manual and is therefore not restrictive.
2.3 Student pilot information
The 25-year-old student pilot was undergoing IR/SE training at Iroise Aéro Formation and was performing his second flight. Holder of a private pilot license for airplanes, he had logged 200 flight hours.
He indicated that the final approach went well and that on flaring, a strong gust destabilized the aeroplane. The instructor, who was monitoring the approach with one hand on the stick, then announced that he was taking control.
2.4 Instructor Information
The 38-year-old instructor had held an aeroplane commercial pilot license since November 2016 and an aeroplane instructor rating since February 2017. He had logged 830 flight hours, including 35 hours in the last three months.
He explained that the threat of strong crosswind was identified before departure. They had taken a full fuel load in anticipation of a possible diversion to Morlaix Ploujean aerodrome or Dinard Pleurtuit Saint-Malo aerodrome.
During the flight, the wind strengthened, though it did not require a diversion according to him. This threat and its mode of management had been mentioned with the student pilot during the arrival briefing.
The instructor specified that he was unable to recover the situation in time when the aeroplane was destabilized on the roll axis.