What was found
(CAN) DURING CRUISE FLIGHT PILOT FELT SUDDEN VIBRATION IN THE M/R FLIGHT CONTROLS SYSTEM. A/C LANDED AT FIRST SUITABLE SITE. UPON INSPECTION, AME DISCOVERED THAT THE 'SCREW IN' RETAINING CUPS ON ONE OF THE M/R PITCH LINKS LOWER ROD ENDS DISINTEGRATED THUS ALLOWING THE BEARING INNER RACE TO SLIP OUT OF THE OUTER RACE.THE ANTI-ROTATION PINS IN ROD END WERE INTACT(REFER TO ATTACHED PHOTOS. SOME DAMAGETOTHE ROTATING SWASHPLATE HORNS WAS ALSO SUSTAINED.THIS PARTICULAR P/N ROD E ND IS SUBJECT OF EUROCOPTER AS355 SB 05.19. IT HAS BEEN FURTHER DETERMINED THAT THE ANTI-ROTATION RIVET WAS NOT ENGAGED IN N EITHER THE OUTER RACE' NOR ROD END'STHREADS - THUS NO LOCKING ACTION.