As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TO FROM CYQX DURING CLIMB OUT APU FIRE DETECTION SYSTEM INDICATED A FALSE FIRE WARNING FOR 1 SECOND FOLLOWED BY "B" LOOP REMAINING ILLUMINATED. AFTER APPROX 1 HR "B" LOOP EXTINGUISHED. BOTH LOOPS TESTED NORMAL AFTER FALSE FIRE WARNING.