As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: BURNING ODOR COMING FROM PACK SYSTEM NOTICED ON TAKEOFF AND CLIMB, IT WAS ALSO PRESENT DURING DESCENT. J/C 08L00021001 T/S SOF INITIAL ACCOMPLISHED. REMOVED AND REPLACED RECIRCULATION AIR FILTERS ON THE LEFT HAND (AALA202602094012) AND RIGHT HAND (AALA202602099286). PER AMM 21-25-01.