As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6506 - IAD-BOS - DURING CLIMB, AN UNSCHEDULED LANDING DUE TO NR 2 COMM UNIT INOP. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED REMOVED AND REPLACED NR 2 COMM UNIT, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)