Thanks CRAN and Thomas Coupling.
I shall bombard my engineer with all this and baffel him to bits.
Thinking about it, the tail rotor moving forwards and up in to the MR downwash sounds totally logical to improve effectiveness but I still wonder if any gyroscopic force plays any part.
Talking of tail rotor noise. Is a CW rotating tail-rotor any quieter than a CCW tail-rotor due to the decreased speed of airflow over it?