What was found
ON APPROACH TO HOME BASE THE CREW HAS AN APU FIRE WARNING. THEY RAN THE CHECKLIST & DISCHARGED THE EXTINGUISHER BOTTLE. SIMULTANEOUS TO DISCHARGING THE BOTTLE, THE WARNING INDICATOR WENT OUT. POST-FLIGHT, THERE WAS NO EVIDENCE OF A FIRE. OVERHEAT DETECTOR PN 17343-01-450F WAS FOUND TO HAVE A LOOSE CONTACT IN THE CERAMIC INSULATOR & WAS REPLACED WITH A NEW UNIT. NO OTHER DEFECT WAS FOUND IN THE FIRE DETECTION SYS.