A320
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 140; Flight Crew Total 12900; Flight Crew Type 1630
Aircraft Equipment Problem Critical
Flight Crew Diverted; General Maintenance Action
Aircraft
With the exception of a security ordered return to the gate to remove a bag; everything was normal and the First Officer was flying. We were climbing out of [departure airport] and were accelerating through 250 KTS and 10;000 FT when the aircraft began a consistent; rhythmic shudder. It stopped around 12;500 FT for a short time and began again. We had no ECAM alerts or messages; just the airframe vibration. We decided to level at FL200 and slowed to 250 KTS and began trouble shooting by going through the system pages. We noticed that the right aileron indicator was vibrating at the same rate as the aircraft. We contacted the flight attendants for their input and were told that it could be felt throughout the airplane and passengers were showing signs of concern. We initiated contact with Dispatch and Maintenance through ACARS. The aircraft was always in control; but the vibration was quite uncomfortable. Because the shudder was nauseating; we made the decision to divert [to a nearby airport]. We did not declare an emergency as we were receiving priority handling and the aircraft was responding normally. We did a few normal turns in the descent to see if we could gather additional information for Maintenance; however; the vibration continued to the ground. I exercised emergency authority to execute an overweight landing. The landing; roll out; and taxi in were all normal. Upon deplaning; a couple of passengers mentioned that they could see the aileron 'fluttering in the wind'; but didn't want to alarm other passengers by saying anything. We were able to pass this information on to Maintenance.
A320 Captain reported abnormal aileron vibration severe enough they decided to divert to nearest suitable airport.