What was found
SECOND AIR QUALITY EVENT OCCURED DESENDING OUT OF FL270. PACK 2 WAS OPERATIVE. MUSTY SMELL AGAIN.-DUE TO HISTORY OF AIR QUALITY EVENTS, TI 2100-2004 ISSUED AND PERFORMED. PERFORMED AMM TASK 36-12-00 DECONTAMINATION OF THE BLEED AIR DUCTING SYSTEM. NO ODOR NOTED AT THIS TIME ON ENG 1, ENG 2, OR APU BLEED.