What was found
(CAN) IT WAS NOTED THAT ON THE LAST SHUTDOWN A NOISE WAS BEING GENERATED FROM THE T/R BLADE ASSY REGION. IT WAS MENTIONED TO AN ENGINEER AND THEY CARRIED OUT A EQUIVALENT TO A 30 HOUR INSPECTION AS PER AD 84-064-037(B)R3. (NO DISASSEMBLY) A VERY SLIGHT NOISE WAS HEARD. THE ENGINEER DECIDED THAT THE 500 HOUR INSPECTION AS PER AD WAS TO BE CARRIED OUT (DISASSEMBLY). A LONGITUDINAL CRACK WAS FOUND ON THE TAIL ROTOR SPAR. TAIL ROTOR WAS REMOVED FROM SERVICE.