What was found
ON CLIMBOUT BEFORE LEVEL FLT WITH FLAPS EXTENDED CONTROL WHEEL BINDING & ABRUPT YAWING MOTIONS WITH MINOR VIBRATION & RUMBLE EXPERIENCED AT FLAPS 10.5 DEGREE WITH AP ENGAGED. BINDING WAS STILL PRESENT WITH MINIMUM YAWING MOTION ON APPROACH (MIA). BINDING & YAW MOTIONS STILL PRESENT WITH FLAPS AT 25 & 30 DEGREES. RETURN TO MIA WITHOUT INCIDENT. DURING TESTING OF AILERON SYSTEM, FOUND BOTH THE COPILOTS AND PILOT DRUM TO HAVE WORN BEARINGS. REPLACED BOTH UNITS IAW 27-11-04/05. ACCOMPLISHED AILERON AND AILERON TRIM SYSTEM RIG PER MM, PERFORM GROUND FUNCTIONAL TEST, FOUND SATISFACTORY, AIRCRAFT RETURNED TO SERVICE FOR NON-REV. FLIGHT. ACCOMPLISH FLIGHT, NO DEFECTS NOTED, AIRCRAFT RETURNED TO SERVICE FOR RE