As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VTB/IAD - FLT 6230 - DURING CRUISE AT 2010 HOURS ON 4-21-97, MADE AN UNSCHEDULED LANDING DUE TO NR 1 AHRU FAILED IN-FLIGHT. AIRCRAFT RETURNED TO GATE AT BTV WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED AHRU, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)