To: Grisoni
When in a zero g condition the rotor is unloaded and therefore, difficult if not impossible to control. By pulling back on the cyclic, you load the rotor. Meanwhile the tail rotor is still effective and as a result imparts a right roll component. In the process of loading the rotor, if the cyclic is positioned as indicated in the diagram it can add to that right roll component causing the helicopter to roll right in what might be a non recoverable situation. Not my words, they are in the POHs for the R22 and R44. If you look at the diagram you can see how easy it is to input the additional right roll component.
Regarding SN-24 stating that the rotor stall will cause the blades to tip back similar to that of retreating blade stall. I will agree with that but only if you are talking about a Bell helicopter. The Robinson rotor head incorporates a coning (flapping) hinge and as such it will do the same thing that a fully articulated rotorhead would do in a stall condition. The blades will fold up on the hinge and not flap back as described in SN-24. Now, if Frank Robinson wants to counter that statement he is welcome to do so.
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The Cat