What was found
DURING DESCENT, THE AILERON TRIM LOCKED UP COMPLETELY. AILERONS WERE FUNCTIONAL BUT FELT HEAVY IN FLIGHT. AIRCRAFT ROLLED TO THE RIGHT WHEN SPEED BRAKES APPLIED. SPOILERS DEPLOYED ASYMMETRICALLY WITH SPEED BRAKE HANDLE OUT OF STOWED POSITION. FOLLOWED COM PROCEDURES AND LANDED SAFELY AT MSP WITHOUT SPOILERS. MAINTENANCE FOUND LEFT SLAT PANEL DRAIN VALVE CLOGGED AND SUSPECT ICE BUILD-UP RESTRICTING CONTROL CABLE MOVEMENT. REPLACED SLANT PANEL DRAIN VALVES AND DRAINED TRAPPED WATER. OPERATIONAL CHECK NORMAL.