Taken from another web site
I have flown BK's with and without the pitch and roll sas. The ones without, at high speed about ten knots less than vne, you start to feel a sort of buffeting which is a symptom of the onset of retreating blade stall. If you reduce pict and slow down it goes away. i worked with a pilot that had a violent pitch up(rt=etreating blade stall) of this aircraft twice. The aircrat i flew with the pitch sas never felt like it was on the edge, but that doesn't mean it wasn't. In this ship I once experienced a pitch up of the nose in level cruise flight. I had full forward cyclic, to the stop and it didn't stop until I lowered collective. I think this had something to do with the spas system not working properly. The spas is something of interest read up on it.