As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY RETURN TO FIELD AFTER TAKEOFF BECAUSE OF APU FIRE INDICATION. APU FIRE INDICATION REMAINED AFTER APU BOTTLE FIRED. INDICATION WENT OUT WHEN THRUST LEVERS BROUGHT BACK TO ABOUT 60 PERCENT N1. FOUND UPPER CLAMP ON APU LCV FAULTY. REMOVED AND REPLACED UPPER CLAMP ON LCV AS REQUIRED. OPS CHECK GOOD IAW MM 49-51-01.