What was found
ON FINAL APPROACH, THE NR 2 ENGINE FIRE AND MASTER WARNING LIGHTS ILLUMINATED. WHEN THE POWER LEVER WAS RETARDED TO IDLE, THE INDICATIONS EXTINGUISHED. TROUBLESHOOTING WAS PERFORMED AND IT WAS DISCOVERED THAT ONE OF THE FIRE LOOP INSULATORS HAD BECOME UNSEATED ALLOWING THE PRIMARY AND SECONDARY SENSING LOOPS TO MAKE CONTACT CAUSING THE FALSE INDICATION. THE FIRE LOOPS WERE INSPECTED FOR THE PRESENCE OF ANY DAMAGE, THE INSULATOR WAS RESEATED AND THE SYSTEM HAD A SUCCESSFUL OPERATIONAL CHECK PERFORMED. THE AIRCRAFT WAS SUBSEQUENTLY RETURNED TO SERVICE.