As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD/DTW - FLT 6428 - DURING CRUISE AT 1230 HOURS ON 4-24-97, AIRCRAFT MADE AN UNSCHEDULED LANDING DUE TO NR 2 ADC FAILED IN-FLIGHT. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED NR 2 ADC, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)