Incident grave de l'hélicoptère Alouette 3 immatriculé HB-XXM survenu le 28/04/2017 à Steffisburg [Enquête menée par SESE / Suisse]

Données préliminaires issues de la notification des autorités de la Suisse :

After the completion of the proficiency check flight, the crew flew back to Wilderswil. in the region of Steffisburg at an altitude of about 3500 ft, the pilots heard a bang. The flight instructor took over the control of the helicopter and initiated an autorotation despite strong vibrations, the flight instructor could land the helicopter on a meadow without damage. On the ground, the crew found that the tail rotor control cable was broken.