What was found
KLAX - ON CLIMB-OUT, NR 3 ENGINE A/B FIRE LOOP INDICATORS ROSE INTO UPPER BAND. FIRE WARNING LIGHTS, NR 3 FIRE SWITCH, AND FIRE WARNING BELL SOUNDED INTERMITTENTLY. ENGINE FIRE CHECKLIST ACCOMPLISHED. FIRE WARNING LIGHTS EXTINGUISHED, NO FIRE BOTTLE DISCHARGED. PERFORMED INSPECTION AND T/S. FOUND PRECOOLER CRACK. REPLACED NR 3 ENGINE BLEED AIR PRECOOLER. SYSTEM CHECK NORMA ON ENGINE RUN-UP. NO FURTHER FIRE WARNING FAULTS NOTED. (M)