Speaking from the perspective of US helicopters only, and by memory.
You must stay at or above single engine airspeed...this is calculated in the power and performance charts and is dependent on the gross weight of the A/C. Then perform what is called a run on landing at or above this airspeed. You will not be able to hover.
I believe most helicopters have the equivelent of a "Sprague" clutch, which disengages the engine drive in the event of an engine failure. Without this an auto rotation would not be possible, because the engine would still be coupled to the drive train.
On some of the real ones you can take the engine power control lever (PCL) into lockout or emergency governor (for you old hands), enabling you to demand a little more power out of the remaining engine, dont know if this is modeled in Black Shark.
Hope this helps. :thumbup:
