What was found
(CAN) BEFORE FLIGHT, ON GROUND, DURING FREE MOVEMENT CHECK OF THE ELEVATORS, CREW NOTICED ABNORMAL PLAY AND CLICKING AT MAX COURSE UP AND DOWN. THEY ALSO REPORTED THAT UNDER AUTO PILOT AT LOW SPEED DURING APPROACH, FIRST TIME BETWEEN 220 AND 200 KTS AND SECOND TIME BETWEEN 180 AND 160 KTS. THERE WERE ABNORMAL VIBRATIONS IN THE CONTROL COLUMN. ONCE AUTO PILOT DISCONNECTED, NO MORE VIBS OBSERVED AND NORMAL FEELING FELT IN THE ELEVATORS.