Is this thread creep?
SAS
Why are you on the computer on Christmas Day? Oh all right then, escaping the rellies just like me!
I don't think anyone (even me) thought that NL was referring to the rotor system when he was talking about drag. He was talking about the horizontal stabiliser.
Anyway, a quick point of aerodynamics for you and Aser (nice graph, Aser!). You can stop reading now if you already understand it!
Once you get to the top of Aser's graph at the stall line, an aerofoil (other than one tethered in a wind tunnel) tends to find the region to the right of the stall line quite unstable due to the fact that lift reduces as angle of attack increases. (angle of attack being defined as the angle between the relative airflow and the chord line). Take a fixed-wing wing - as the angle of attack exceeds that stall line the wing loses lift and starts to drop. The very fact that the wing is descending through the air increases the angle of attack further, which reduces its lift, which makes it descend faster, which increases its angle of attack further still etc.
The same applies to a horizontal stabiliser. In forward flight its pushing the tail down but as airspeed reduces, the angle of attack increases due to the increasing angle of downwash from the main rotor and at some point it gets to the top of Aser's graph and lift starts to decrease. As soon as that happens, the tail starts to come up and that increases the angle of attack, losing (downward) lift which further increases the angle of attack etc. That's why the hover attitude suddenly takes a step change as the stall is reached, rather than a gradual change as might be implied by Aser's graph
So although it looks as though you could function happily just to the right of the stall line, in reality you couldn't, and you fall off the right-hand side of the graph as soon as you touch the stall line.
This phenomena is very noticeable on the Super Puma family. The auto-hovering AS332L2 could get into an oscillating syndrome where the hover attitude varied between level and about 7 degrees nose up when hovering in about 40 kts of wind as the stabiliser cycled through stalling / unstalling.
Possibly it doesn't happen on the S92 but I think the chances are it does and that is why 212 says the hover attitude is more nose high in strong wind than in light wind.
Nick will no doubt argue but we should remember that whilst Eurocopter, Sikorsky etc are the experts in designing and building the aircraft, Bristow, CHC, Bond, Norsk, Cougar, PHI, (even Shell!) etc are the experts in operating them and the total hours ever flown by Sikorsky on the S92 is exceeded by the operators every month.
HC