What happened
During the final approach, approximately one-quarter mile from the runway threshold, the captain attempted to correct for a crosswind by applying right aileron. The pilot reported that the control yoke felt as though it had bound up, requiring the use of excessive pressure to achieve a response. Despite this difficulty, an uneventful landing was completed.
While taxiing following the landing, the captain cycled the control yoke left and right. After several cycles, the controls appeared to move freely. However, during an intentional sharp left turn, the tiller wheel again appeared to bind.
The investigation
Maintenance personnel conducted a nose landing gear wheel steering test and inspected the cable tension for the nose wheel steering. During this process, a leak was identified in the right-hand nose steering accumulator, though it was determined to be within allowable limits.
Further inspections included the case drain plugs, filters, and the left and right aileron cables from the main wheel well outboard. Following standard maintenance procedures, mechanics also performed an internal leak check on the aileron PCU. No discrepancies were found during these checks. The aircraft was subsequently test flown and returned to service. No data could be recovered from the DFDR to explain the event as described by the pilot.