As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
REC INFLIGHT - NUMBER ONE ENGINE FIRE DETECTION LOOP ONE FAULTED WITH LEFT ENGINE LOOP TWO PLACARDED. RETURNED TO REC AND LANDED WITHOUT INCIDENT. REPLACED FIRE DETECTION SYSTEM LOGIC CARD AND TIGHTENED LOOSE LEFT ENGINE LOOP ONE LOWER AFT CONNECTOR AND REPLACED FAULTY LT ENGINE LOOP UPPER AFT CONNECTOR. SYSTEM GROUND CHECKED NORMAL OPERATION.