CL65 DECLARES EMER AFTER EICAS MESSAGES COMBINED WITH ACFT CTL PROBS START ADDING UP. RETURNS TO CVG.

Narrative

ON CLBOUT (APPROX 10000 FT); CREW GOT AN 'ANTI ICE DUCT' WARNING. MESSAGE CLRED AS WING ANTI-ICE SYS WAS TURNED OFF. QRH PROC WAS COMPLETED AND ACFT LEFT ICING CONDITIONS AND DID NOT RE-ENTER ICING CONDITIONS. AFTER CONSULTING WITH MAINT AND DISPATCH; CREW DECIDED TO RETURN TO CVG. AS ACFT WAS TURNING TOWARDS CVG; EICAS INDICATED 'AUTOPLT TRIM IS RWD.' CAUTION MESSAGE WAS INTERMITTENT. AFTER DISCONNECTING AUTOPLT; AILERONS FELT VERY STIFF ALTHOUGH RESPONDING CORRECTLY. INCREASING PRESSURE ON AILERONS ATTEMPTING TO BANK THE AIRPLANE RESULTED IN A 'SNAP' AND ACFT ROLLED SHARPLY. IMMEDIATELY RETURNED AILERONS TO NEUTRAL. ANOTHER ATTEMPT TO BANK HAD SAME RESULT. EMER WAS DECLARED. AILERON PROB SEEMED TO CLR ITSELF AND FLT CTLS WERE NORMAL FOR REMAINDER OF FLT. VISUAL APCH AND LNDG WAS MADE WITHOUT INCIDENT. CONTRIBUTING FACTORS: 1) 5 DAYS PRIOR; ACFT HAD SAME 'ANTI ICE DUCT' WARNING. 2) AIRPLANE SAT ON TXWY IN HVY RAIN FOR OVER 1 HR PRIOR TO DEP. I DO NOT SUSPECT THAT THE ANTI-ICE PROB AND THE AILERON ABNORMALITY ARE RELATED.