What was found
DURING FLIGHT, NR 1 ENGINE FIRE SHORT CIRCUIT LIGHT, MASTER WARNING LIGHT AND FIRE HANDLE LIGHT ILLUMINATED INTERMITTENTLY, ALL OTHER INDICATIONS WERE NORMAL. OBSERVED NR 1 ENGINE AND FOUND NO ABNORMAL CONDITION EXISTS. AIRCRAFT LANDED WITHOUT INCIDENT. FOUND FIRE DETECTOR CONTROL UNIT FAULTY. REPLACED NR 1 FIRE DETECTOR UNIT PER MM CH 26, SYSTEM OPS CHECKED GOOD.