What was found
(CAN) ON CLIMB OUT, THE PILOT REPORTS NR 1 ENG RPM DROPPED TO 97 PERCENT AND HE WAS NOT ABLE TO RESTORE THE ENG TO 100 PERCENT RPM. PROCEEDED TO MAKE AN UNSCHEDULED LANDING AT DEPARTURE AIRFIELD. UPON INVESTIGATION IT WAS FOUND THAT THE BOLT ATTACHING THE SPEED LEVER TELEFLEX CABLE TO SPEED INPUT SHAFT OF THE FCU HAD BACKED OUT COMPLETELY AND THE CABLE HAD SEPARATED FROM THE INPUT ROD. THE BOLT IN QUESTION WAS RE-USED ON AN ENGINE CHANGE THAT TOOK PLACE 33.6 HOURS PRIOR TO THIS EVENT, ON 11/28/2007. AT THAT TIME THE BOLT MET THE RUN-DOWN TORQUE REQUIREMENTS FOR SELF LOCKING HARDWARE IAW MM STANDARD PRACTICES. THE BOLT WAS REPLACED, THE ENGINE RE-RIGGED WITH NO FAULTS FOUND AND THE AC RETURNED TO SERVICE. (TC NR 20071217006)