The instructor, who was seated in the left seat and was accompanied by a student, flew the helicopter in forward level flight from the parking area to FATO 04 at Grenoble Le Versoud aerodrome for an introductory flight. While slowing down to enter hover, on the approach to the FATO, before take-off, the collective stick suddenly separated from its base. The helicopter yawed to the left and upwards. The instructor, who had only partial control of the helicopter via the cyclic control and the rudder pedals, tried to counter the rotation and keep the helicopter level. The rotor rpm decreased and the helicopter descended. Its tail boom followed by the skids collided with the ground. The helicopter slid and came to rest in the grass at the right edge of the runway. The uninjured instructor and student evacuated the helicopter.
The separation of the collective stick from its base, on the left-seat side occupied by the instructor, while slowing down to enter hover, led to the loss of control of the helicopter in flight.