What was found
DURING CLIMB PASSING FL300, CLIMB SPEED NOTING CONDITION & NO TURBULENCE. THE ACFT HAD A VERY STRONG VIBRATION FOR ABOUT 30 SECONDS. AFTER REDUCING SPEED & DISCONNECTING AP THE VIBRATIONS STOPPED. THE AP WAS CONNECTED AGAIN WITH A/T & WITH SPEED TURBULENCE. APPROACH & LANDING NORMAL. IAW AMM 05-56-00-810-801-A IDENTIFICATION OF THE CAUSE OF AIRFRAME VIBRATION ACCORDANCE REPORT SHEET SHOW SEALS OF THE BELLY FAIRING IAW TSM -53-35-00-810-801. CHECK OF BELLY FAIRING PANELS 191 & 192 BT, 192DT, 192ET WAS PERFORMED. NOT FOUND DAMAGED.