(warning, extreme geek subject
Just curious, Tomas: Have any tests been done to determine the exact rotor phase?
Most of us know that gyroscopic precession is 90 degrees, but heli swash plates do not deliver the control action at 90 degrees, the blade deflection begins earlier (strating a 180 degree arc), apexes at 90 degrees, then continues.
So it has been suggested that the actual phase lag on our helis may be closer to 80 degrees, and that the FBL unit is compensating for this so we don't notice it. (and presumably it will be a bit different owing to blade weight, headspeed, etc.)