As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ERRATIC PRIMARY FLIGHT DISPLAY, LOSS OF ATT, R MAG ON CAPTAINS. AND PITCH FEEL FAULT, YAW DAMPER STATUS STALL FAIL. RETURNED TO FIELD AND MADE A UNEVENTFUL LANDING. MDC SHOWED IRU NR 1 FAILED/NO OUTPUT. REMOVED AND REPLACED NR 1 IRU PER MTC R344501 AND PERFORMED CATIII RETURN TO SERVICE CHECKS PER SAME MTC. RETURNED TO SERVICE.