Thanks Dave and HW. I have contacts at Boeing and Bell. So with the
exception of the Black projects I keep tabs on going on with them.
Searching patent applications lets me get an idea what Sikorskys
thinking about. As HW replied, Sikorsky has patented some Variable
Diameter Rotor concepts. But until I see an effort to build a flying
prototype, even a UAV, I doubt much is going on.

Thanks for the input,

CTR