What was found
AFTER TAKEOFF THE LEFT ENGINE FIRE DETECT FAIL LIGHT ILLUMINATED. THE CREW FOLLOWED THE CHECKLIST BUT THE LIGHT ILLUMINATED AGAIN. CREW DID A PRE-CAUTIONARY AIR RETURN. UPON ARRIVAL AT GATE AND THE LEFT ENGINE SHUTDOWN THE FIRE HANDLE LIGHT ILLUMINATED AND THERE WAS A RISE IN ITT. THE CAPTAIN DECIDED TO BLOW THE FIRE SUPPRESSION BOTTLE, ORDERED AN EMERGENCY EVACUATION ON THE RIGHT SIDE AND SIMULTANEOUSLY CALLED FOR EMERGENCY EQUIPMENT AND PERSONNEL. BOTH GALLEY AND WINDOW EXITS WERE UTILIZED. THERE ARE NO INJURIES OR COMPLICATIONS REPORTED. FOUND CHAFED FIRE LOOP, CHANGED FIRE LOOP, AND FIRE BOTTLE. FERRIED TO IAD FOR REPLACEMENT OF RESISTOR BOX.