redandwhite,
I didn't know that about the UH-1 and find it very interesting.
However, the Huey is an old design with relatively low performance compared to contemperary helicopters of that size and weight. One of the reasons for the improvements achieved is advanced rotor aerofoil design and planform design.
Unfortunalety these improvements come at a cost, which is frequently higher pitching moments and control loads than the famous NACA 0012 aerofoil based rotors (at low speed). I'm guessing that this is what they used on Huey, though I haven't checked (It will certainly be something very similar). When mounted about the quater-chord (ish) 0012 produces very small pitching moments and hence finds lots of applications in early helicopter rotor design.
On the assumption that newer designs such as Squirrel use modern proprietory aerofoils (as all Eurocopter helicopters do) then the larger pitching moments created by these aerofoils will require a hydraulic system in machines that are smaller that you might have expected with lower performance earlier rotors. Don't forget the newer rotor have to operate in even more difficult flight conditioopns than the older ones by virtue of the fact that they can fly faster!
CRAN
