As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD/MBT - FLT 6388 - DURING CRUISE AT 0945 HRS ON 6-25-98. AIRCRAFT MADE AN UNSCHEDULED LANDING DUE TO NR 2 AHRS FAILED. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTION AND REMOVED AND REPLACED NR 2 AHRS COMPUTER. OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)