As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) MCC HAS BEEN ADVISED THAT ACFT CONDUCTED AN AIR TURN BACK DUE TO A DISPLAY SOURCE ANNUNCIATION PREVENTING THEM FROM CONDUCTING A REQUIRED CAT IIIA APPROACHED IN POSSIBLE CAT IIIA CONDITIONS. NR 2 DEU WAS REPLACED AND TESTED SERVICEABLE IAW MM 31-62-21. REMOVE DEU,