What was found
KWRI - ON DEPARTURE OUT OF KWRI, A NR 3 ENGINE FIRE WARNING WAS EXPERIENCED. THE ENGINE WAS PRECAUTIONARILY SHUT DOWN, AND THE AIRCRAFT RETURNED TO KWRI FOR MAINTENANCE. WINDMILLING OIL PRESSURE WAS 30 PSI. INSPECTION AT KWRI REVEALED AN INTERMITTENTLY BAD LOWER FIRE DETECTOR ELEMENT. THE FIRE DETECTOR ELEMENT WAS REPLACED, AND THE ENGINE RUN EXTENSIVELY ON THE GROUND TO VERIFY THE REPAIR. THERE WAS NO RECURRING FALSE FIRE WARNING. THE AIRCRAFT RETURNED TO SERVICE. (X)