What was found
JUST AFTER TAKEOFF FROM RDU, ANTI-ICE DUCT FAIL MESSAGE CAME ON IN FLIGHT. MFD INDICATED A RIGHT FUSELAGE DUCT LEAK. REMOVED AND REPLACED SENSING ELEMENT A18WK IAW CL-65 MM 36-21-04, PERFORMED OPS CHECK IAW CL-65 MM 36-21-00, NO DEFECTS FOUND. ALSO, PERFORMED GROUND RUNS IAW CL-65 MM 71-00-00. COULD NOT GET ANY ANTI-ICE DUCT FAULTS ON THE GROUND. ALSO, ACCOMPLISHED FUNCTIONAL CHECK FLIGHT DUE TO REPORTED PROBLEM. NO DEFECTS FOUND. AIRCRAFT RETURNED TO SERVICE.