As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6510 - IAD-LGA - DURING CRUISE, AIRCRAFT MADE AN UNSCHEDULED LANDING DUE NR 1 AHRS FAILED IN FLIGHT. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED NR 1 AHRS, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)