What was found
(CAN) ON A ROUTINE FLT THE PILOTS COULD HEAR A NOISE IN THE CONTROL COLUMN WHEN MOVING IT BACKWARDS AND FORWARDS. WHEN THE AIRCRAFT RETURNED MAINTENANCE FOUND THE LEFT ELEVATOR TAB BINDING AT THE CONTROL ROD TO TAB HORN ATTACHMENT. THE BUSHING HAD MIGRATED SUCH THAT IT WAS BINDING WHEN THE ELEVATOR WAS MOVED CAUSING OIL-CANNING IN THE SKIN. A NEW BUSHING, NUT, BOLT AND COTTER PIN WERE INSTALLED AND RIGGED. THE SYSTEM WAS CHECKED SERVICEABLE AND THE AIRCRAFT RETURNED TO SERVICE.