kissmysquirrel-
I was calling the typical Bell semi-rigid, two-blade rotor, a "teetering" head. Because they tilt freely at the head and mast, they seem to be more problematic in the wind. If a gust tips the disc with enough energy to encounter the droop stops, the disc can start bouncing off the stops. That cycle's phase becomes is the strongest influnce on disc tilt and isn't easily controlled once excited, as it occurs at low RPM when cyclic is ineffective. If the blade hits the stop at the most inopportune time, the aft blade will flex and strike tailboom, winglets, whatever, in spite of the fuselage being aligned with the wind, cross wind, or down wind.