As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TYS - FLIGHT 2110 PERFORMED AIR RETURN DUE TO ABNORMAL SMELL FROM NR 2 PACK. A/C WAS RELEASED IAW MEL 21-51-00/2 CAT-C CONTROL 041491 TO TYS WHERE MAINT REMOVED AND REPLACED THE NR 2 ENG IAW ROLL ROYCE MM 72-00-00. ALL WORK WAS ACCOMPLISHED WITH LEAK, VIBES AND OPS CHECKS GOOD. A/C RELEASED TO SERVICE AFTER ALL WORK WAS C/W.