What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS DURING DESCENT, THE FLOW LIGHT CAME ON, CABIN STARTED CLIMBING AT OVER 1000 FT/MIN. THE AFT GALLEY DOOR LIGHT CAME ON, THE AIRCRAFT STARTED VIBRATING EXCESSIVELY AND THE CABIN ALTITUDE WENT UP 9500 FEET. FLIGHT ATTENDANT HEARD LOUD VIBRATION THROUGHOUT ENTIRE CABIN. THEY SAID IT WAS THE LOUDEST AT THE REAR OF THE AIRCRAFT. NUMBER 4 FLIGHT ATTENDANT REPORTED AIR RUSHING THROUGH AFT GALLEY DOOR ALONG WITH THE VIBRATION. MAINTENANCE ACCOMPLISHED EXTERNAL VISUAL CHECK OF ALL EXTERIOR DOORS AND PANELS, NO DEFECTS NOTED. RAN PACKS AND FOUND RT PACK DUCT DISCONNECTED FROM OUTPUT OF ACM. REINSTALLED DUCT, AND ACCOMPLISHED PACK AND CABIN PRESSURIZATION CHECKS, INCLUDING AFT GALLEY SERVICE DOOR. ALL CHECKS NORMAL.