LW50,
While the blackhawk/seahawk has a tail rotor vertical fin with aerodynamic properties that offsets tail rotor thrust , almost completely at around 120 KIAS, the S92 does not.
In the BH/SH you do not have to enter auto if you lose tail rotor drive in forward flight because of the aerodynamic properties of the vertical fin, in the S92 you have to enter auto because the vertical pylon does not stop you from spinning.
Not sure why they did not incorporate the vertical fin into the S92, it just makes sense to me.
TalkSpike.