What was found
NOSE GEAR DOWN INDICATION FAILED TO ILLUMINATE WHEN GEAR WAS EXTENDED. CREW ABORTED APPROACH TO WORK AFM CHECK LIST FOR GEAR PROBLEM. AFTER GEAR WAS BLOWN DOWN, NOSE GEAR DOWN IDICATION WAS GOOD. SEVERAL MOMENTS LATER, NOSE GEAR DOWN INDICATION FAILED AGAIN. CREW DECLARED EMERGENCY AND PROCEDED TO LAND, NOSE GEAR DOWN INDICATION CAME BACK ON PRIOR TO TOUCH-DOWN AND AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE PERSONNEL FOUND DEFECTIVE NOSE GEAR ACTUATOR. ACTUATOR REPLACED, GEAR RETRACTION FUNCTIONAL CHECK SATISFACTORY, AIRCRAFT RETURNED TO SERVICE.