What was found
PHL - FLT NR 183 - ON FINAL APPROACH, CREW COULD NOT GET 3 GREEN LIGHTS ON THE GEAR. THE LEFT MAIN GEAR LIGHT TESTED BUT WOULD NOT ILLUMINATE. CYCLED GEAR, THEN AN INTERMITTENT LEFT LANDING GEAR DOWNLOCK SWITCH LIGHT ON MULTIFUNCTION DISPLAY UNIT. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED THE LEFT MAIN GEAR DOWNLOCK ACTUATOR AND RIGGED PER MM. (Z)