As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6499 - IAD-ROA - DURING CRUISE, AIRCRAFT MADE A SCHEDULED LANDING DUE TO F/O'S AHRS FAILURE. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED F/O'S AHRS. OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)