B727 CREW; DEPARTING SLC; EXPERIENCED A FIRE WARNING ASSOCIATED WITH THE CARGO LOWER FUSELAGE AREA. RETURNED TO SLC.

Narrative

DEPARTING RWY 35; AT 1500 FT AGL; THE AFT CARGO FIRE LIGHT ACCOMPANIED BY THE FIRE WARNING BELL AND THE LOWER AFT BODY OVERHEAT LIGHT ILLUMINATED. THE FLT ATTENDANTS RPTED HEARING AN EXPLOSION BELOW THE FLOOR IN THE REAR OF THE ACFT; FOLLOWED BY A LOUD VIBRATION; VISIBLE SMOKE AND INCREASING HEAT. I TOLD THE COPLT TO CONTINUE FLYING; TALK TO ATC; DECLARE AN EMER AND REQUEST AN IMMEDIATE RETURN TO SLC. THE ENGINEER AND I RAN THE CHKLISTS. THE #2 ENG WAS BROUGHT TO IDLE TO REDUCE PNEUMATIC PRESSURE TO THE 48 SECTION AND REDUCE SMOKE AND HEAT. THE PACKS WERE LEFT ON FOR VENTILATION OF SMOKE AND ANTI-ICE ON FOR ICING CONDITIONS. #2 ENG WAS LEFT AT REDUCED THRUST TO NOT ADD TO THE PROB IF IT WAS THE CAUSE. THE ACFT WAS AT LIGHT WT AND HAD NO PROB CLBING TO 10000 FT AS INSTRUCTED BY ATC. I APPRISED THE FLT ATTENDANTS AND PAX OF THE SIT AND INSTRUCTED A FLT ATTENDANT TO REMAIN ON THE INTERCOM. THE RECALL ITEMS FOR SMOKE/FUMES WERE ACCOMPLISHED. THE CARGO FIRE CHKLIST WAS COMPLETED WITH THE #1 BOTTLE DISCHARGED. THE FLT ATTENDANTS RPTED THERE WAS STILL SOME SMOKE AND HEAT COMING FROM THE REAR OF THE ACFT AND THAT THEY HAD MOVED ALL PAX TO THE FRONT OF THE CABIN. THE CARGO FIRE BELL SOUNDED AGAIN ON DOWNWIND APCHING THE TURN TO BASE LEG. I MANUALLY DISCHARGED THE #2 FIRE BOTTLE INTO THE AFT CARGO COMPARTMENT. THE LOWER AFT BODY OVERHEAT CHKLIST WAS INITIATED BUT NOT COMPLETED DUE TO THE ACFT'S CLOSE PROX TO FINAL APCH AND THE NEED FOR ALL CREW MEMBERS TO MONITOR THE APCH AND SAFELY LAND THE ACFT. I INSTRUCTED THE ENGINEER TO PREPARE FOR THE EMER EVAC CHKLIST. THE LOC AND GS FOR RWY 34L WERE INTERCEPTED OUTSIDE OF THE OM FROM A NORMAL PROFILE DOWNWIND AND BASE LEG. A FULL STOP WAS COMPLETED AND THE FIRE TRUCKS RPTED NO VISIBLE FLAMES OR SMOKE FROM THE ACFT. THE CARGO FIRE LIGHT AND AFT BODY OVERHEAT LIGHT WERE STILL ILLUMINATED IN THE COCKPIT. THE FLT ATTENDANTS RPTED THE SMOKE WAS NOT DISSIPATING. I CALLED FOR THE EMER EVAC CHKLIST AND IT WAS COMPLETED BY THE COPLT AND ENGINEER. I TOLD THE FLT ATTENDANTS TO PREPARE FOR EVAC AND NOTIFIED TWR WE WOULD BE EVACING FROM THE L SIDE. I GAVE THE EVAC COMMAND WITH INSTRUCTION TO ASSEMBLE IN FRONT OF THE ACFT. THE EVAC WAS CALM AND ORDERLY THROUGH DOOR 1L. WHEN THE EVAC WAS COMPLETE; I MADE A SWEEP OF THE ACFT AND WAS THE LAST TO LEAVE. EVERYONE WAS TAKEN BY BUS TO THE TERMINAL WHERE THEY WERE MET BY ARPT PERSONNEL. THERE WERE NO INJURIES RPTED TO PAX OR CREW. SUPPLEMENTAL INFO FROM ACN 532879: THE FLT ATTENDANTS STILL RPTED SMOKE IN THE CABIN SO THE CAPT GAVE THE EVAC CHKLIST ORDER WHICH WAS ACCOMPLISHED BY MYSELF AND THE SO. ONCE IT WAS COMPLETE; THE SO WAS FIRST DOWN THE SLIDE FOLLOWED BY MYSELF TO HELP CATCH THE PAX. I ASKED THEM TO ORGANIZE IN FRONT OF THE NOSE OF THE ACFT. AFTER ABOUT 6 PAX DOWN THE SLIDE THE FIRE FIGHTERS ARRIVED AND TOOK OVER CATCHING PAX DOWN THE SLIDE. LAST OFF WAS THE CAPT.