As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON DESCENT THROUGH 9000 FEET, LOUD REPEATED BANGING SOUND FROM AIRCRAFT. COMBINED WITH SHARP REPEATED LEFT YAW MOTIONS. C/W SECU CHECKS, SPOILER AND SPOILERON CHECKS. CHECKED HYD SYSTEM HEAT EXCHANGER. CHECKED RUDDER AND RUDDER TRIM SYSTEM. COMPLIED WITH ACCEL AND DECCEL ENGINE CHECKS AND C/W VIBE CHECKS. FOUND INTERMITTENT FAILING YAW DAMP ACTUATOR NR 2. REMOVED AND REPLACED YAW DAMP ACTUATOR NR 2. (M)