What was found
AIRCRAFT WAS GROUNDED: POSSIBLE FUME EVENT TOWARDS REAR OF AC ONLY ON INITIAL CLIMB THEN AGAIN ON IDLE DESCENT, NEVER ON GROUND AFT FA DETECTED ACRID EXHAUST TYPE ODOR.DESCRIBED AS SMELLY FEET AND METALLIC. NOT DETECTED WHILE ONGROUND AIR OR APU BLEED. **SUPPLEMENTAL REPORT FOR SDR AALA202510129316**(CLOSED) MAINTENANCE ACCOMPLISHED W/C 26L00021001, APU WAS THE SOURCE OF ODOR. REPLACED APU OIL DRAIN PLUG IAW AMM 24-23-51.