As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ACFT WAS LEAVING AIRPORT WHEN CREW WERE ALLERTED TO SMOKE AND FUMES. ACFT RETURN TO BLOCK AND WAS FERRIED TO WHERE MX R & R THE NR 1 ENGINE IAW TASKCARD 6271001. COMPLIED WITH THE AIR CONDITIONING DUCTS CLEANING TASK IAW AMM 21-20-00-100-805-A, STEP K 1 THRU 20. OPS AND LEAK CHECKS GOOD AND WAS RELEASED BACK TO SERVICE.