What was found
AT FL 330 CABIN ALT WARNING HORN SOUNDED. IMMEDIATELY DESCENDED TO FL 230. REQUESTED LOWER, REGAINED CONTROL PASSING FL 180. L1 DOOR SEALS, OUTFLOW VALVE, WATER SEPARATOR CLAMP, MAIN CARGO DOOR SEAL, CLEANING AND SEALING OF FUSELAGE BILGE DRAINS, ALSO REF KAIR WORK ORDER 933700374 FOR R&R OF MULTIPLE COMPONENTS. R&R OF PRESSURE CONTROLLER IAW AMM 21-31-21. PERFORMED OPERATIONAL CHECK IAW IAI SUPP MANUAL 21-31-00 NO DEFECTS NOTED.