As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DTW - FLT 631 - ON FINAL INTO TPA, NR 1 ENGINE A-LOOP FLICKERED WITH NO ASSOCIATED WARNING EXCEPT M-CAUTION FLICKERED ONCE FOR 2 SECONDS, SELECTED B-LOOP AND EXECUTED TEST. TEST WAS NORMAL. REMOVED AND REPLACED LEFT ENGINE FIRE LOOP. (M)