As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RDU - FLT 1826 - DURING APPROACH TO RDU, APU FIRE INDICATION ILLUMINATED FOR APPROXIMATELY 2 SECONDS AND THEN EXTINGUISHED. SIMULTANEOUSLY, APU AUTO-SHUTDOWN. APU FIRE BOTTLE DISCHARGED AND AIRCRAFT LANDED RDU WITHOUT INCIDENT. REPLACED APU FIRE BOTTLE AND PLACARDED APU INOPERATIVE. SUBSEQUENTLY, REPLACED APU FIRE DETECTION CONTROL UNIT AT ORD/17. SYSTEM GROUND CHECKED NORMAL OPERATION. APU OPERATION WITH AIR AND ELECTRIC CHECKED NORMAL. (X)