As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT PASSING THROUGH FL180 AND 250 KIAS THE UPPER RUDDER BEGAN TO OSCILLATE, THIS WAS PHYSICALLY NOTICABLE IN THE AIRFRAME. TROUBLESHOT AND FOUND UPPER RUDDER ACTUATOR TO BE FAULTY. REPLACED UPPER RUDDER ACTAUTOR PERFORMED UPPER RUDDER SYS ADJUSTMENT AND OPS TEST. ALL WORK DONE IAW MM 27-24-01 NO DEFECTS NOTED AT THIS TIME.