What was found
INSPECTION TYPE:N/A DURING DESCENT NR 1 ENGINE FIRE WARNING (AUDIBLE ONLY) WAS OBSERVED BUT INTERMITTENT. THROTTLE WAS RETARDED TO IDLE. CONSISTENT WITH PROCEDURE & ALL INDICATIONS CEASED. ENGINE WAS LEFT AT IDLE, EMERGENCY WAS DECLARED & LANDING WAS UNEVENTFUL. SWAPPED APU FDCU WITH NR 1 ENG FDCU AND PERFORMED SYS OPERATION TEST PER AMM 26-11-02, SYS OPS CKS GOOD. OK FOR SERVICE.