What was found
ON C-CHECK, FWD CARGO, A/C DISTRIBUTION BAY HAS SEVERAL A/C DUCTS JOINED TOGETHER WITH TAPE. AIR LEAKING FROM THESE AREAS. REPLACED RUBBER BOOST AT Y-DUCT ASSY AREA CLAMPS AT TOP SIDE, IAW MM OPS 21-20-4. SYSTEM REQUIRES OPS AND LEAK CHECK FOR COMPLETION OF WORK AND DUCT INSTALLATION IAW B-727 MM 21-20-4.