As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
F/O ADI BANKS 1/4 OF CAPTAINS AND DURING TURNS HORIZON FLAG ILLUMINATED. F/O HSI HAS OFF FLAG AND DRIFTS FROM CAPTAIN''S HSI. REMOVED AND REPLACED F/O''S ADI. OPS CHECKED OK IAW M/M 34-20-0 AND LITTON LTR-97 SUP M/M 34-20-25. RERACKED HSI INDICATOR AND COULD NOT DUPLICATE PROBLEM. SWAPPED NR 1 AND NR 2 HSI FOR FURTHER TROUBLESHOOTING. OPS CHECK OK IAW M/M 34-21-0 AND LITTON LTR-97.