What was found
SMOKE CARGO WARNING IN FLIGHT FROM RDU TO DCA. CAPTAIN DECLARED AN EMERGENCY. ACTIVATED FIRE BOTTLE, LANDED AT DCA WITH NO PROBLEM. CARGO COMPARTMENT AND AFT BAY SECTION WAS INSPECTED BY MAINTENANCE AND FOUND TO BE IN SAFE CONDITION FOR FERRY FLIGHT TO RDU. IT WAS DETERMINED TO BE A FALSE WARNING. OPERATIONAL TEST OF CARGO FIRE DETECTION SYSTEM WAS PERFORMED IAW MM 26-15-00. NO FAULTS FOUND AT THIS TIME. REMOVED AND REPLACED (FWD) AND (AFT) SMOKE DETECTORS IN CARGO BAY IAW 26-15-00. REMOVED AND REPLACED RT AND LT CARGO FIRE BOTTLES IAW 26-25-04. OPERATIONAL TEST SATISFACTORY.