Incident Description
The captain reported that while in cruise flight, the center autopilot made an uncommanded disconnect. He took control of the aircraft and found that the rudder and elevator systems appeared to be functioning normally but the control wheel was jammed in the straight and level position. Approximately 15 pounds of force was applied to free the control wheel. The flight was diverted and an uneventful landing was made.
Examination Findings
A postaccident examination revealed that the wheel well canted pressure deck drain lines were obstructed by debris.
Service Bulletin
A Boeing service bulletin was found that recommends changes to the drain system to "...help ensure that fluid entering the canted pressure deck area will be drained out of the airplane and not leak into the wheel well area where it could freeze on the aileron control cables..."
Weather and Arrival
The aircraft arrived at JFK on June 6, 2000 at 1956 eastern daylight time. Weather reports for the JFK airport show rain during the night of June 6, 2000 and during the morning of June 7, 2000.