What was found
ON FLIGHT 3464 THE CREW REPORTED THAT WHEN FLYING THE AIRCRAFT THROUGH MEDIUM TO HEAVY PRECIPITATION THE CREW NOTICED AN ODOR IN THE COCKPIT THAT SEEMED LIKE A MILDEW. IT WENT AWAY AFTER EXITING PRECIPITATION. THE ODOR WAS ONLY NOTICED IN THE COCKPIT NOT IN CABIN. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. RE-SECURED LEFT PACK DUCT IAW EMB-145 AMM 21-20-04. THE OPERATIONAL CHECK WAS GOOD. NO MILDEW ODOR NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE.