Dear all, don't be tempted to confuse the issue between STATIC and DYNAMIC roll over.
The various definitions of static roll over are quite correct, the C of G is positioned in such a way (either through landing on a slope, towing the helicopter onto a slope or taxiing too quickly) that the helicopter literally falls over!
A helicpter can be committed to a crash due to dynamic roll over at an angle much less than that required for static roll over. As has already been mentioned, the rolling moment that is generated and the ability to counter it with cyclic is what matters. The only role that the collective plays is to help generate the rolling moment, lowering the collective is the most important corrective action.
It is possible to get dynamic roll over on a flat surface! A Bell 212 rolled over in Canada due to one skid being frozen to the hard standing it was parked on, the other was exposed to the sun and had thawed out. As the pilot pulled in power the old girl flipped onto her side, if ever there was an advert to apply collective slowly then this is it.
As mentioned the Puma family are likely candidates for both of the above due to the high C of G, however, ALL helicopters are liable to roll over if not handled correctly.
Anyway, that's enough from me; I'm off to teach yaw/roll divergence and rotor droop in the Puma.......
