As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAX - FLT 1716 - EN ROUTE LAX-AUS, INTERMITTENT FIRE WARNING OF LEFT ENGINE AFTER TAKEOFF WITH LEFT ENGINE IN LOOP A ONLY. RETURNED LAX AND LANDED WITHOUT INCIDENT. CHECK OF LEFT ENGINE FIRE DETECTION LOOP A WORKS NORMAL. REPLACED LEFT ENGIEN RIGHT IGV ANTI-ICE DUCT. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)