Incident Overview
During a descent through 12,000 feet, with the 'A' system autopilot engaged and an airspeed of 250 knots, the aircraft experienced an uncommanded roll to the left. The captain immediately disengaged the autopilot and rolled the airplane to wings-level flight. The remainder of the flight was conducted with the autopilot off.
Inspection Findings
A post-incident examination of the aircraft revealed an intermittent electrical connection in the 'A' autopilot circuit. Specifically, pin connector(s) had been pushed out of place on the flight control computer shelf connector. One of the affected pins was in the aileron position sensor excitation circuit.
Maintenance History
The 'A' flight control computer had been removed and reinstalled the day before the incident to inspect the rack for fluid contamination. It is possible that this maintenance contributed to the pin displacement, though the source does not explicitly state a causal link.