What was found
LOWER EXTERIOR FUSELAGE STA 363 S28R SKIN BULGE BETWEEN FASTENERS. GROUNDED - YES. EVALUATED SKIN BULGE. FOUND TO BE CORROSION OF LOWER SKIN AND STR28R. REMOVED SKIN CORROSION AND CORRODED STRINGER SECTION. NDT INSPECTIONS ACCOMPLISHED. FABRICATED REPAIR PARTS AND INSTALLED IAW 900-53EA-24340. REINSTALLED MULTIPLE DUCTS IAW B737-900 AMM 21-27-10-400-801, AMM 21-27-04-400-801, AMM 21-27-08-400-801. OPS CHECK GOOD OF ALL REMOVED EQUIPMENT. REINSTALLED ALL FLOOR BOARDS REQ FOR REPAIR. IAW B737-900 AMM 21-27-05-400-801, 21-27-05-410-001. AND B737-900 SRM 51-40-02.