What was found
AFTER TAKEOFF, CLIMBING THROUGH 10000 FT, COCKPIT RECIRC FAN WAS SWITCHED ON HI. A STRONG ODOR OF BURNING AND MELTED PLASTIC WAS NOTED. FAN WAS TURNED OFF, BUT ODOR CONTINUED AND SEEMED TO GET STRONGER. NO SMOKE WAS NOTED. CO-PILOT NOTED A RATTLING SOUND COMING FROM THE RECIRCULATION FAN WHEN IT WAS ON. PERFORMED ENG RUN , NO NOTICEABLE ODOR OF MELTED PLASTIC IN COCKPIT OR CABIN , COCKPIT RECIRULATION FAN HAS BAD BEARING DEFECTIVE UNIT ORDERED NEW FAN ASSY, R & R COCKPIT RECIRC FAN IAW MM 21-22-00. OPS CHECKED NORMAL.