Twitchy Tail in the S61
Just looking for a couple of ideas here gents. N model S61 on descent around 35-40% Torque, tail wags back and forth a bit. Yaw channel off, still there, AFCS off still there, Aux off still there, but more pronounced. Does not do it in a hover or climbing flight, only descent. Came to light about 6 weeks after a T/R gearbox change. Aux servo has been replaced since, problem still there.
Its aerodynamic so im leaning towards NFG problem? Open to suggestions.....