What was found
FLIGHT CREW PERSONNEL REPORTED ON THE INITIAL CLIMBOUT OF FLIGHT 883-1 FROM PIE, THE FIRE DETECTOR HANDLE AND LOOP "B" ILLUMINATED ON THE LEFT ENGINE. THE AIRCRAFT RETURNED TO ST. PETERSBURG, FL AND LANDED WITHOUT INCIDENT. MAINTENANCE DEPARTMENT PERSONNEL PERFORMED A VISUAL INSPECTION OF THE LT ENGINE FIRE DETECTION "B" SYSTEM AND DETERMINED A FIRE LOOP DETECTOR WAS DEFECTIVE. THE "B" LOOP WAS DEFERRED IAW ALLEGIANT AIR MEL PROCEDURES AND THE AIRCRAFT WAS RETURNED TO SERVICE. (A)