Accident to the Airbus EC120 registered F-HBKY on 19/07/2023 at Dax
Hard landing during autorotation training
This is a courtesy translation by the BEA of the Final Report on the Safety Investigation. 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 the pilots’ statements. This information has not been independently validated by the BEA.
1. History of the flight
The pilot-in-command was an instructor in the company. He was accompanied by another pilot for an autorotation training session. After taking off from the company’s base situated on Dax-Seyresse aerodrome, the pilot-in-command, in the right seat, headed for Dax Tinon HLS composed of several unpaved strips. He made an initial approach on an easterly heading in order to carry out a reconnaissance of the grass strip that was going to be used and the environment.
The second pilot carried out a first autorotation, started at 1,000 ft/100 kt, with the engine re-engaged on flaring. The same pilot then carried out two complete autorotations (engine idling) up to landing.
The pilot-in-command then took the controls and took off in order for him to carry out a complete autorotation. He started the exercise. He indicated that at the end of the flare and on increasing the collective pitch, the helicopter still had a substantial forward speed and vertical speed. The helicopter made flat, hard contact with the ground and slid on the grass. The main rotor blades struck the tail boom.
2. Additional information
2.1 Damage observed
The impact of the main rotor blades damaged the tail boom and caused the fenestron to separate.
2.2 Pilot-in-command information
The pilot-in-command held a helicopter commercial pilot licence with the AS355 and EC120B ratings valid at the time of the accident. He had logged a total of 7,830 h including 792 h on type of which 12 h in the 90 days preceding the accident.
The pilot-in-command specified that this type of autorotation training session was programmed twice a year by the company, for the instructors. It was a single-pilot operation but there had been a briefing which had covered the possibility of the second pilot having to intervene.
The pilot-in-command stated that during the descent, the parameters and flight path were correct. In his opinion, he did not sufficiently flare and over anticipated the increase in collective pitch. He explained that after the hard contact, the helicopter was shaken by the uneven ground due to its forward speed which caused movements to the main rotor. Furthermore, the pilot indicated that he might have pulled the cyclic pitch stick back as a reflex, to brake the helicopter. After coming to a stop, the helicopter entered resonance until the engine was shut down by an action on the twist grip.
According to the pilot-in-command, the second pilot had alerted him about the flare being insufficient and the over anticipation of the increase in collective pitch. The pilot-in-command did not perceive the second pilot’s verbal intervention to be of a nature to directly call into question continuing the manoeuvre.
2.3 Meteorological information
The weather conditions collected by the pilot-in-command indicated visibility greater than 10 km, a ceiling higher than 2,000 ft, north-north-east wind of 5 to 10 kt and no precipitation.
December 2023