What was found
AT 6000 MSL ON APPROACH, FLAPS 1, 210 KTS., SMELLED A BITTER, ACID, OILY SMELL IN THE COCKPIT. TURNING OFF PACK 1 IMPROVED THE AIR QUALITY. F/A DID NOT SMELL ANYTHING ABNORMAL. DIFFERENTIAL PRESSURE 2.9 PSI -PER GMM 30.40 ODOR EVENT STAGE 1. APPLIED TSM 05-50-810-831-A DECISION TABLE POINTS TO CORRECTIVE ACTION TYPE 1, LEVEL OF ODOR IS B. APU INSPECTION REQ SEE L/P 6010517-2. DECANTAMINATION LEVEL B REQ. SEE L/P 6010518-1