As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED A BURNING ODOR ON DESCENT THROUGH FT 280 AND AGAIN AROUND FT 180. THE ACFT LANDED WITHOUT INCIDENT. ACFT REMOVED FROM SERVICE. COMPLIED WITH ETN EM-72-034R4. NO ODOR NOTED AT THIS TIME. THE ACFT WAS RETURNED TO SERVICE.