What was found
MCO - ON CLIMBOUT AT ABOVE 1700 WITH CLIMB POWER, LEFT B-LOOP CAME ON. SHORTLY AFTER LEFT A-LOOP CAME ON. LEFT FIRE WARNING CAME ON IMMEDIATELY. LEVELED OFF AT 18,000 AND PULLED POWER BACK TO 1.40 ENGINE PRESSURE RATIO AND WARNING WENT OUT. RETURNED TO MCO AND LANDED WITHOUT INCIDENT. NO FURTHER WARNINGS WERE OBSERVED AT ANYTIME. SHUTDOWN ENGINE AFTER LANDING. REPLACED RUPTURED REAR ANTI ICE DUCT ON LEFT ENGINE. SYSTEM GROUND CHECKED NORMAL OPERATION.