"Some cases of dislodging of lower half scissor spherical bearings Part Number (P/N) 3G6230V00654 have been reported on in-service helicopters. These bearings are installed on main rotor (M/R) Rotating Scissors P/N 3G6230A00733.
As a result of the investigations accomplished by the supplier of the spherical bearings, it was determined that a quality issue might have affected the production of these bearings.
This condition, if not detected and corrected, could lead to loss of control of the helicopter."
OMG they're duplicating the scissors!! - one of the safest things around! now they too can be unreliable.
Simplex is good, duplex should be used with caution ( if ever ).
2 engines didn't help here..