As Nick already said:
The high velocity of the airstream needed to provide the same force as a conventional tail-rotor is the reason. This is why a Notar asks for an extra power that reduces payload (compared to a tail-rotor design).
And as maintenance of fast rotating machinery goes up the faster things rotate...
You see: A notar is probably _not_ the best idea for utility flying. Even in Canda.
With kind regards from Germany,
Robert
BTW: I'm now _no_ VFR driver any more
