As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) IN CRUISE FLIGHT CREW GOT A FIRE INDICATION ON BOTH LOOPS AND SHUTDOWN THE NR 3 ENGINE AND DISCHARGED BOTH FIRE BOTTLES. INVESTIGATION REVEALED NO ACTUAL FIRE. CAUSE OF THE FALSE INDICATION WAS A CHAFED WIRE ON LOOP A AND A MISSING GASKET ON LOOP B, BOTH LOOPS WERE IN THE SAME ZONE OF THE ENGINE/NACELLE. THE LOOP AND GASKET WERE REPLACED AND THE AIRCRAFT RETURNED TO SERVICE.