What was found
AT 40,000 FT NOTICED THE AUTOPILOT DOING BABY DUTCH ROLLS TO STAY ON COUSE. AFTER DISSCONNECTING THE AUTOPILOT FOUND NEITHER PILOT HAD CONTROL OF THE AILERONS. ACFT WOULD NOT TURN WITHOUT EXCESSIVE FORCE APPLIED TO THE YOKE. OUSIDE AIR TEMP -35 TAT. -64 SAT. AFTER DECENDING TO FL240 AND WAITING ABOUT 20 MINS , WE REGAINED NORMAL CONTROL OF THE AILERONS. AIR TEMP AT FL240 , TAT 4 , SAT -25.