As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, FIRE DETECTOR LOOP ANNUNCIATOR HAS ILLUMINATED & THE LOOP B ON THE RT ENG WAS ALSO ILLUMINATED. SWITCH TO LOOP A, GOT A GOOD FIRE TEST. LT SWITCH IN LOOP A POSITION IAW THE CHECKLIST. ACCOMPLISHED BITE TEST ON FIRE DETECTION UNIT IAW AMM TASK 26-00-00-2. TEST ON BOTH LOOP A & B ON RT ENG NORMAL. OK FOR SERVICE.