As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLT AT FL410, NR2 IRS FAILED. WE WERE ABLE TO REVERT AND USE NR1 IRS INFO. CHECKED FAULTS AND FAULTS FOR PREVIOUS LEG CALL FOR RETURN TO SERVICE & MONITOR PER HONEYWELL FAULT ISOLATION MANUAL. NO PREVIOUS HISTORY OF IRS FAULTS. SYSTEM OPERATIONAL CHECKED NORMALLY WITH NO FAULTS OR DEFECTS AT THIS TIME IAW CE750 MM CHAPTER 34-43-01