What was found
DURING APPROACH FOR LANDING WHEN SLATS EXTENDED, THE SLAT DISAGREEMENT LIGHT ILLUMINATED AND THE AIRCRAFT ROLLED. FOLLOWED COM PROCEDURES AND THE FLIGHT ATTENDANT VERIFIED THE RIGHT SLAT DID NOT DEPLOY. FLAP ONLY LANDING AT MSP WAS UNEVENTFUL. MAINTENANCE DISCOVERED THAT THE SLAT WOULD NOT FALL OUT OF RIGHT WING AND IT APPEARED TO BE HANGING UP ON THE T-DUCT. REPLACED THE RIGHT T-DUCT AND OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.