When you look at RBS analytically it is generally with respect to the airspeed over the rotor disc. As you go faster eventually the whole retreating side has negative airspeed. RBS comes before that point as the blades need a higher AOA to preserve symmetry of lift. Extra blades are no guarantee against RBS.
Seems much too early to speculate. I am sure the data will tell its tale. My heart goes out to Bell, my former competitors yet we are brothers all.
Last edited by IFMU; 10th Jul 2016 at 23:40.
Reason: Last paragraph added