What was found
DURING CLIMBOUT A INTERMITTENT THUMPING NOISE WAS HEARD WHICH APPEARED TO BE COMING FROM UNDER THE 1ST CLASS CABIN. THUMPING CONTINUED AT CRUISE FL330 FOR ABOUT 15 MIN AND THEN QUIT. INSPECTED E&E, FWD CARGO PIT, FWD DOORS INCLUDING E&E, L1, L2, F/CARGO DOOR ALL UNITS IN RDO RACKS FOR SECURITY. NO DISCREPANCIES NOTED. PLATES, SKIN, ANTI, ALL CK OK.