As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EN ROUTE FROM DFW TO DTW, THE AILERON FLIGHT CONTROLS FROZE. AIRCRAFT DESCENDED TO A LOWER ALTITUDE AND CONTROL RETURNED. FLIGHT DIVERTED TO MEM AND MADE A NORMAL SAFE LANDING. MAINTENANCE FOUND THE RIGHT SLANT PANEL DRAIN VALVE CLOGGED. CLEARED OBSTRUCTION AND AIRCRAFT RETURNED TO SERVICE.