What was found
DURING INITIAL CRUISE FLIGHT F/A INDICATED FUME LIKE ISSUE IN AFT CABIN. PORTABLE OXYGEN USED FOR REMAINDER OF FLIGHT. DECLARED EMERGENCY RETURNED TO SAN. GROUNDED - YES. AIR TURNBACK - CONSULTED WITH PILOTS. NO ODORS WERE PRESENT DURING TAXI OUT BUT F/A REPORTED FEELING ILL. AN HR INTO FLT MULTIPLE FLIGHT ATTENDANTS HAD SAME SYMPTOMS. PERFORMED IFIM TASK 21-00-00-810-830. SMOKE OR FUMES IN CABIN, SOURCE UNKNOWN. CONFIRMED APU DRAIN MAST IS CLEAN. CONFIRMED HYD RESERVIORS ARE SERVICED CORRECTLY. PERFORMED ENG IDLE RUN & RAN PACKS FOR 10 MINS & NO ODORS OR SYMPTOMS PRESENT. PER IFIM DEFECT IS INTERMITTENT. NO HISTORY FOUND. REF LOGPAGE 61135643, R & R LT & RT RECIRCULATION AIR FILTERS PER SAMC RECOMMENDATION.