As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ACRID ODOR AFTER DEPARTURE CLEARED UP AT CRUISE ALTITUDE THEN DESCENDING THROUGH 10K ACRID ODOR RETURNED. MAINTENANCE ISOLATED THE SOURCE OF THE ODOR TO THE APU. **SUPPLEMENTAL REPORT FOR AALA202303136249: MAINTENANCE REPLACED THE APU OIL TANK CAP PER AMM 49-91-48 AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK.** (CLOSED)