As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED ANTI-ICE DUCT RED CAS MESSAGE DURING CLIMBOUT FROM TYS WITH WING AND COWL ANTI-ICE ON. CREW RETURNED TO TYS AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT THE AIRCRAFT, REMOVED AND REPLACED FUSELAGE SENSING ELEMENTS A38WK AND A18WK AND PERFORMED CHECKS USING THE AIRCRAFT MAINTENANCE MANUAL. AIRCRAFT WAS RELEASED FOR SERVICE.