Aircraft
The accident involved a Eurocopter AS350 Écureuil, registered as F-GIBM, operated by Dolijet, a company chaired by Olivier Dassault. The airframe had accumulated over 8,000 flight hours, and its most recent airworthiness certificate was issued in July 2020. Two days before the crash, the pilot and a mechanic noted that the artificial horizon indicator was inoperative.
Accident
On 7 March 2021, the helicopter was scheduled to fly from a private helipad in Touques, Calvados, Normandy, to another privately owned helipad in Beauvais, on property belonging to Dassault. The landing site, chosen the previous day, was surrounded by trees, the tallest reaching 23 meters. Shortly after engine start, the helicopter entered a hover, then climbed vertically near the trees. The main rotor struck a tree at approximately 19 meters. The impact caused the tail boom to separate, with 90% of its rivets shearing. An overtorque on the main rotor hub ripped away the front passenger seats. The aircraft yawed while moving forward, fell, and struck the ground about 50 meters from the takeoff point.
Investigation
France's air accident investigation bureau, the BEA, investigated the crash. The BEA concluded that the chosen landing site restricted the possibility of a safe takeoff maneuver. They noted that the pilot had a small safety margin with tree branches that were in shade, and may have had difficulty assessing the distance to those branches because of the shade and low light contrast. The BEA issued two safety recommendations: one concerning training for operating this type of aircraft in confined areas, and another regarding awareness of age-related degradation of visual performance.