412 M.R.
Jumping back a few items in this thread.....
Since it was mentioned, The main rotor system in the Bell 412 is actually a "soft-in-plane" rigid rotor, flex-beam type. (straight out of product data) I'm not a rotors guy, but I've been told that being "soft-in-plane" makes it behave more like an articulated rotor than a rigid rotor. It's technically called a rigid rotor because it doesn't really have a hinge like an articulated, it instead bends the material that attaches it to the mast to create almost the same effect. ..... if that helps.
My understanding is the fully articulated has the best ride - which makes sense since the blades are able to move with the most independence from the aircraft. A soft-in-plane rigid rotor is very close and differs only by the fact that there's no physical hinge.
The teetering rotor is next, as far as pure ride goes. The 2-per-rev can still get you though, but systems like the nodal beam suspension on the 206L-4 tranny correct for that, and gets the ride about as good as you can get with a teetering rotor.
BO-105s and the like, with true rigid rotors, are akin to sports cars with stiff, or almost non-existent suspensions. They can do fantastic maneuvers, but the price you pay is a rough ride. Every bump that goes into the rotor gets translated into the airframe. Every gust that lifts a blade gets translated into the airframe, etc. But I tell you it’s wild to watch them stand on their nose as they take off. On a rigid, when you tilt the disc... the whole world tilts with you.
Nick Lappos used to have some diagrams explaining all this stuff on his website but my link to it doesn’t work anymore.
Last edited by Avnx EO; 19th Sep 2003 at 23:18.