As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, IT WAS NOTED THAT THE NR 2 AHRS WAS 10 DEGREES OFF FROM WHAT THE STANDBY HEADING SYSTEM AND THE WET COMPASS WERE READING. AIRCRAFT WAS RETURNED TO DEPARTURE POINT. MAINTENANCE COULD NOT DUPLICATE PROBLEM ON GROUND. NR 2 AHRS COMPUTER WAS RE-RACKED AND OPS CHECKS WERE GOOD. AIRCRAFT WAS THEN RETURNED TO SERVICE WITH NO FURTHER DIFFICULTIES NOTED.