As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING DESCENT AT APPROX FL180 FELT A VIBRATION BENEATH COCKPIT FLOOR. VIBRATION WAS ACCOMPANIED BY A SMELL OF BURNING. BURNING SMELL PERSISTED UNTIL LANDING. UPON INVESTIGATION OF SOURCE OF VIBRATION & SMELL FOUND BLOWER FAN RATTLING AND MAKING NOISE. R&R BLOWER(20HQ) IAW AMM 21-26-51. OPS CK GOOD NO OTHER DEFECTS NOTED.