What was found
ON DESCENT ABNORMAL SMELL FROM PACK 1 SHUT OFF PACK 1 AND THE SMELL DISSIPATED AT OR BELOW FL 370. PERFORM DECONTAMINATION ON THE ENVIROMENTAL CONTROL SYSTEM IAW AMM 21-00-00 AND 21-00-00-615-004. DID NOT FOUND ANY SIGN OF OIL LEAK. R&R THE RECIRCULATION FILTERS AND PERFORM ENGINE RUN-UP IAW AMM 71-00-00. ALSO REACTIVED PACK NR 1 DUE TO ON MEL NO ODOR SMELL IN CABIN THIS ACTION CLEARS DMI 212833601 PLACARD REMOVED MOC NOTIFIED.