What was found
DEBRIEFED INBOUND FLIGHT, COMMENTED THAT COMING INTO SFO WHEN FLAPS WAS BEING LOWER, AIRFRAME STARTED TO RUMBLE AND FEELS LIKE A LATERAL VIBRATION. PER FLIGHT CREW, HAS HISTORY ON FLAPS ISSUE. CK TRAILING FLAP FAIRING AND FOUND TO BE NORMAL, ALSO CK NLG DOORS AND FOUND LT SMALL DOOR HAVE PLAY ON HINGE, ALSO STARTED THE TROUBLESHOOTING TSM AND RESULTED ON THE RUDDER AS THE SOURCE OF VIBRATION. FOUND CUSHION SEALS BETWEEN I/B & O/B FLAPS DAMAGED. RESEARCHING PARTS. REPLACED SEALS.