As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, NR 3 FIRE LIGHT ILLUMINATED AND BELL SOUNDED, FOLLOWED PROCEDURES. LEFT BOTTLE DISCHARGE LIGHT DID NOT ILLUMINATE. FIRE HANDLE LIGHT DID NOT EXTINGUISH. INSPECTED ENGINE AND FOUND NO FIRE. REMOVED AND REPLACED FIRE DETECTION ACCY UNIT. PERFORMED TEST. GROUND TEST NORMAL. (M)