A321 captain experienced rudder vibration in flight.

Attributes
ACN	1649674
Time
Date	201905
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	A321
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Component
Aircraft Component	Rudder
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Events
Anomaly	Aircraft Equipment Problem Less Severe Inflight Event / Encounter Other / Unknown

Narrative:

While on approach with the flaps extended and autopilot engaged; both pilots felt the rudder pedals rapidly moving about an inch or two. The rudder pedal movement stopped when the autopilot was disengaged and did not reoccur. After entering the incident in the log book; I was contacted by a member of my union's safety committee who informed me that there have been approximately a dozen similar instances on this particular aircraft.

Original NASA ASRS Text

Title: A321 Captain experienced rudder vibration in flight.

Narrative: While on approach with the flaps extended and autopilot engaged; both pilots felt the rudder pedals rapidly moving about an inch or two. The rudder pedal movement stopped when the autopilot was disengaged and did not reoccur. After entering the incident in the log book; I was contacted by a member of my union's safety committee who informed me that there have been approximately a dozen similar instances on this particular aircraft.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.