To Imlanphere
The drive to the fan is coupled to the main transmission in the same way as any TR drive,so providing ONLY engine failure and you enter auto its driven in just the same way as normal.
You do actually require the fan to work because after all it is just like losing an normal TR.(NOT GOOD)
Hope this clears it up.
Any other questions on the NOTAR fire away
and I'll try and answer them.
Regards
hoverbover