What was found
(CAN) PILOT REPORTED OF FROZEN AILERONS AT CRUISE ALTITUDE. AIRCRAFT RETURNED TO BASE. DURING DESCENT PILOT WAS ABLE TO REGAIN CONTROL. INVESTIGATION FOUND EXCESIVE AMOUNT OF WATER IN AILERON BRUSH SEALS. BRUSH SEALS CLEANED, DRIED AND RE-LUBRICTED PER M.M. 27-21-02 WITH ADC (D.C.33) GREASE. FUSELAGE FLOORBOARDS AND BELLY PANELS OPENED TO INSPECT CABLE RUNS. NO IRREGULARITIES NOTED. PANELS CLOSED. AILERON FUNCTION FOUND FULLY FREE AND NORMAL. AIRCRAFT TEST FLOWN AND RETURNED TO SERVICE.