As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BAD SMELL OF DIRTY SOCKS NOTED DURING DESCENT WHILE RH PACK SELECTED ON AND LH PACK SELECTED OFF / REMOVED AND REPLACED R/H RECIRCULATION FAN FILTER IAW CRJ900 AMM 21-22-12-400-801-A01 AND FIM 21-21-00-810-806 AND 21-22-00-810-806. OPS CHECK GOOD AND LEAK CHECK GOOD.