What was found
NR 1 ENGINE FIRE WARNING LIGHT IN FLIGHT PERF ENGINE FIRE CHECKLIST WE WERE IN A LOOP TRANSFER TO DMI 25877 IAW MEL 26-2-3 SYS INSP. ENGINE NO DEFECTS NOTED CAT C SPECIAL PROCEDURES C/W PLACARDS INSTALLED.)REF DMI 25877 NR 1 ENG FIRE WARNING LIGHT IN FLIGHT PER ENG FIRE CHECK LIST IN "A" MODE REPLACED NR 1 ENG LEFT FAN FWD LOOP AND BOTH CORE LOOP AND PYL LOOP PER MM26-12-12 AND RUN UP ENG PER JRH 13.5 OPS OK THIS CLEAR DMI#25877.