so it's not a tail rotor then
Its a fan blowing air down the tail boom to the coanda slot and the buckety-blower arrangement.
Check the causes of LTE:
https://en.m.wikipedia.org/wiki/Loss..._effectiveness
1. Main-rotor vortexes pushed into the tail rotor by wind.
2. Wind from the tail (6 o'clock) can cause the helicopter to attempt to weathervane into the wind.
3. Wind moving in the same direction as the tail rotor moves air
1 cannot happen with NOTAR, but it is not prone against 2 and 3.