The 350 MRH is described as a starflex semi-rigid type. It is semi-rigid iaw the old books because it has no drag damper as per the 76, 61, 330 and 332L2 types. It does however allow for dragging via the starflex and damper fitted to the blade root end which practically makes it a "fully articulated" head. The 332L1 has a similiar argument as the frequency damper is not a drag damper thus semi-rigid, but does allow inflight up to 2 degree drag angle due to it's elastomer build. It is difficult fitting this technolagy in to the old definitions, guess Sikorsky has the right idea by calling it a elastometric head. The 350 with it's droop ring allows for 3 dimensional movement inflight which definately does not comply with any traditional definitions in my opinion.