Shawn,
You may wish to ask Sikorsky about the mast fairing, which is yet to be installed.
Two patents;
7,607,607 ~ De-rotation system suitable for use with a shaft fairing system, and
7,621,480 ~ De-rotation system for a counter-rotating, coaxial rotor hub shaft fairing
show many potential mechanical and electrical means of limiting its rotation.
Apparently, the uncontrolled rotation of the mast faring is due to the fact that it is located between a clockwise rotating rotorhub and a counter-clockwise rotating rotorhub. It appears that there is nothing stationary to attach mast fairing to.
Dave
P.S. If you want to be mischievous, you can ask them if the
Intermeshing-ABC has a mast.
