As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FUME EVENT OCCURRED PASSING FL 180 250 KNOTS AND CONTINUED TO 12,000. SEEMED TO CLEAR BUT STARTED AGAIN ON DESCENT TO LANDING. MAINTENANCE ISOLATED SOURCE OF ODOR TO THE APU. **SUPPLEMENTAL REPORT FOR AALA202111010609: MAINTENANCE FOUND THE APU OIL COOLING FAN LEAKING DUE TO A BROKEN SEAL. REPLACED SEAL AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK PER AMM 49-52-51** (CLOSED)