What was found
AUTO PILOT PORPOSING IN LEVEL FLIGHT. DURING RT ELEVATOR CABLE ADJUSTMENT CHECKED TRAVEL TAB IN BOTH DIRECTION. WITH STICK FULL FORWARD THE LEFT ELEVATOR TAB ONLY GOES UP. THE RIGHT ELEVATOR TAB STAYS AT THE SAME POSITION. AFTER TROUBLE SHOOTING WE FOUND THE STOP SCREW (THE UPPER ONE ) COMPLETELY LOOSE ON RIGHT SYSTEM, CAUSING THE RESTRICTING TRAVEL OF TAB IN TRAILING EDGE UP. AFTER CORRECTING ACTION, THE TRAVEL CHECK IS NORMAL