What was found
WHILE FLYING TO DESTINATION, THE LT ENGINE FIRE LIGHT ILLUMINATED. 1 PASSENGER WAS ABOARD. PILOTS MADE A PRECAUTIONARY DIVERSION TO OTHER AIRPORT WHICH WAS THE CLOSEST AIRPORT. UPON LANDING, UNLOADED THE PASSENGER AND CALLED OUR MX DEPARTMENT AND OPS DEPARTMENT. A HELICOPTER AND MECHANIC WERE DISPATCHED. THE HELICOPTER DROPPED OFF THE MECHANIC TO FIX ACFT AND THE OTHER HELICOPTER TOOK THE PASSENGER TO DESTINATION. THE MECHANIC TROUBLESHOT FIRE DETECTION SYS, FOUND TOP FIRE DETECTOR ON THE NR 1 ENGINE TO BE BAD AND REPLACED FIRE DETECTOR. ACFT WAS RETURNED TO SERVICE AND FLOWN BACK TO BASE.