Phoinix says:
EC135, maybe even MD900 from the looks of it.
and Otterotor says:
The Model 430 (out of production) and the H-1 Upgrades, Yankee and brother Zulu all Bell aircraft that have feathering flexures eliminating the feathering bearing.
Thanks guys. For people interested, I found a Google Book excerpt that mentions exactly these rotor systems:
https://books.google.com/books?id=rv...20head&f=false
plus the Comanche rotor system which it claims was a derivative of the BO-108 (EC135) rotor design. Cool designs although visually the cuff reminds me a bit of a Brantly rotor system! :-)
