Synopsis
The aircraft was cruising at 33,000 ft, when it encountered moderate turbulence. This turbulence resulted in a moderate un-commanded roll. While the autopilot was correcting this roll, the outer bracket supporting the outside servo-control of the RH inboard aileron failed, causing the RH inboard aileron to oscillate quickly from 14 degrees upwards deflection to 12 degrees downwards deflection and settling at an upwards deflection of the order of 15 degrees. This did not cause any control problems and the autopilot was able to continue to control the aircraft. The aircraft landed without difficulty at the intended destination, Chicago O’Hare (KORD). Subsequently a crack was detected in a corresponding bracket on the Left Hand (LH) wing.
