As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHIP 1601 DURING TAXI OUT, FLIGHT ATTENDANT REPORTED A BURING SMELL NEAR ROWS 32-40. RELIEF PILOT SMELLED IT AS WELL IN COCKPIT, SMELL SEEMED TO INTENSITY WITH RECIRC FANS OFF. CORRECTIVE ACTION: CLEANED LEFT PACK INLET. R/R BOTH RECIRC FILTERS. OPERATED BOTH PACKS FULL HOT FOR 10 MINS WITH LT AND RT ENG BLEEDS. NO ODOR PRESENT. (4994536)