SOS
I was an IP
Flying with student at qualification trg
Task - simulated engine failure at altitude
After initial, not ideal-student overrides me, I stopped that, nose turns right 20-30 deg then abnormaly continues turn
Hanged with left skid lower
At 110 deg i put collective down thought tail rotor had failed
Contacted ground with left skid inertially moving backward
Rolled on the left side
Blade hit the ground and broke