As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: UPON START OF APU SMOKE AND FUMES FILLED THE CABIN AND COCKPIT. AIRCRAFT RETURNED TO BCN, LARGE OIL LEAK FOUND IN APU. **SUPPLEMENTAL REPORT FOR SDR AALA202401319610.** (CLOSED) MAINTENANCE REMOVED & REPLACED APU PER JOB CARD 72L31049008.