What was found
(CAN) OCCURRENCE WHERE THE ENGINE SPEED CONTROL DISENGAGED FROM THE FUEL CONTROL UNIT, RESULTING IN AN IN-FLIGHT SHUTDOWN OF THE ENGINE. SUSPECTED CAUSE WAS A LOOSE SELF LOCKING BOLT, P/N NK4-4A, AND OR A WORN NON METALLIC LOCKING INSERT ON THE NK4-4A BOLT. IN ORDER TO PREVENT THIS FROM HAPPENING AGAIN, THE MAINTENANCE CREW HAVE BEEN REMINDED TO TAKE CARE WHEN INSTALLING THE SPEED CONTROL WHEN RE-USING THE NK4-4A BOLT TO ENSURE THAT THERE IS THREAD INTERFERENCE. MM, SA 4045-80, SECTION 20-00, PAGE 5, PARAGRAPH 9 (REUSE OF SELF LOCKING NUTS), SUB-PARAGRAPH C. STATES THAT ALL NUTS MUST BE CHECKED BEFORE RE-USE. THERE MUST BE THREAD INTERFERENCE, SUCH INTERFERENCE INDICATES THAT THE SELF LOCKING FEATURE IS WORKIN