A BEECH 1900D ON TAXI OUT DECLARED AN EMER DUE TO A #2 ENG FIRE WARNING CAUSED BY A FAULTY FIRE WARNING LOOP ASSEMBLY.

Narrative

DURING TAXI OUT TO RWY 14L AT IAH; THE #2 FIRE T-HANDLE ILLUMINATED AND A MASTER WARNING ANNUNCIATOR WAS FLASHING. THE FO AND I BOTH LOOKED AT THE ANNUNCIATOR PANEL (FIRE LOOP ANNUNCIATOR) FOR A POSSIBLE FALSE INDICATION. NONE WAS SEEN. I ASKED THE FO TO CONTACT ATC; TELL THEM OUR POS AND THAT WE HAVE A FIRE INDICATION FOR #2 ENG AND TO ROLL THE FIRE EQUIP. WHILE HE XMITTED WITH ATC; I TAXIED THE BE1900D INTO THE RWY 14L RUNUP PAD. I STARTED THE MEMORY ENG FIRE/SHUTDOWN CHKLIST AND THE T- HANDLE WAS STILL ILLUMINATED. I ASKED THE FO IF HE COULD SEE ANY SMOKE OR FIRE AROUND THE ENG. HE SAID 'NO' AND I TOLD HIM TO BLOW THE BOTTLE. HE SAID HE COULD SEE HALON ('WHITE STUFF') COMING OUT OF #2 NACELLE. I TOLD HIM TO START AN EVAC OUT THE MAIN CABIN DOOR AND TO PUT THE PEOPLE IN THE GRASS AWAY FROM THE ACFT. I COMPLETED THE ACFT SECURING CHKLIST; MADE SURE THE PLANE WAS EMPTY; AND WENT OVER TO WHERE THE PAX AND FO WERE STANDING. BY THEN THE FIRE EQUIP WAS ARRIVING AND GETTING INTO POS. I TOLD THE FIREMAN THE PROB AND THEY CHKED AROUND THE #2 ENG FOR FIRE/SMOKE. AT THAT POINT; THE FIREMAN DISCOVERED FUEL LEAKING FROM THE BACK OF THE NACELLE AND DRIPPED ONTO THE GND. I CALLED OUR OPS/DISPATCH; RPTED THE INCIDENT; ASKED FOR A PAX BUS; AND FOR MAINT TO COME OUT WITH A TUG. THE ACFT WAS TAKEN TO THE MAINT HANGAR AND RIVETS WERE REPLACED IN THE WET FUEL TANK. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A BEECH 1900D AND THE ENG FIRE WARNING DID NOT APPEAR TO BE A FALSE WARNING. THE RPTR SAID MAINT DID NOT FIND ANY EVIDENCE OF A FIRE BUT REPLACED A FAULTY ENG FIRE LOOP ASSEMBLY AND ALSO CORRECTED THE R WING TANK FUEL LEAK.