As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 6578 - IAD-PWM - DURING CRUISE, MADE A UNSCHEDULED LANDING DUE TO RIGHT ENGINE RPM WOULD NOT GO DOWN BELOW 97 PERCENT IN CRUISE. AIRCRAFT RETURNED TO GATE WITH NO FURTHER INCIDENTS. MAINTENANCE ADJUSTED PROP GOVERNOR LOW RPM. OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)