What was found
ON 3 MAY 2016 AT APPROX 2100 Z WITH 2 SOULS ONBOARD, 1 HR INTO FLIGHT WHILE OPERATING AT 24,000 FT MSL, THE NR 2 RT ENG FIRE & MSTR WARN LIGHTS ILLUMINATED. REDUCED THE RT THROTTLE TO IDLE & THE LIGHTS EXTINGUISHED WITHIN 3 SECS. DECLARED AN EMER & ATC PROVIDED VECTORS, LANDED UNEVENTFULLY, AFTER 2 MINS THE RT ENG WAS SHUT DOWN & TAXIED BACK TO THE LINE. PERFORMED HIGH POWER RUN, INSPECTED FOR BLEED AIR LEAKS WITH NO ADVERSE RESULTS. ALL 3 FIRE SENSING ELEMENTS WERE CHECKED & THE LOWER UNIT WAS FOUND TO HAVE LOW RESISTANCE. THE PART WAS CHANGED OUT, GND TESTED, ENG RUN UP ACCOMPLISHED & RTS. THERE IS NO DOCUMENTATION OF INSTALLATION TIMES & CYCLES OF FAILED SENSING ELEMENT THAT CAN BE LOCATED.