RETURN LAND BY B-737 WITH APU FIRE WARNING LIT.

Narrative

AFTER A NORMAL TKOF FROM RWY 11L AND CLBING OUT OF 3000 FT MSL; THE APU FIRE WARNING BELL SOUNDED AND ASSOCIATED LIGHTS ILLUMINATED IN THE COCKPIT. AS THE PNF THE CAPT WAS PERFORMING THE AFTER TKOF CHKLIST AND SHUT DOWN THE APU AS THE FIRE WARNING INDICATION STARTED. THE PNF ACCOMPLISHED IMMEDIATE ACTION STEPS BY PULLING THE APU FIRE HANDLE AND ROTATING THE HANDLE TO SEND EXTINGUISHING AGENT TO THE APU. THE FIRE LIGHT IN THE APU HANDLE REMAINED 'ON;' SO THE PNF ASKED ATC FOR IMMEDIATE VECTORS BACK TO MSP. THE PF; FO; LEVELED OFF AT 4000 FT MSL AND FOLLOWED RADAR VECTOR INSTRUCTIONS TO LAND BACK AT MSP RWY 22. PNF CONTACTED FLT ATTENDANTS SITTING AFT CABIN AND DETERMINED NO SMOKE OR FUMES ENTERING CABIN FROM TAIL SECTION; SO CAPT AND FO DECIDED NOT TO PREPARE THE CABIN IN TIME AVAILABLE BEFORE LNDG; BUT DID CALL FOR EMER EQUIP TO MEET ACFT ON LNDG ROLLOUT AT END OF RWY 22 AT MSP. TWR COULD NOT SEE ANY SIGNS OF FIRE/SMOKE FROM APU TAIL SECTION AND THE FIRE CHIEF MADE A COMPLETE VISUAL INSPECTION OF THE ACFT WALKING AROUND THE TAIL OF THE ACFT. CAPT AGAIN SPOKE TO FLT ATTENDANTS TO DETERMINE NO SMOKE ENTERING THE CABIN; YET APU FIRE HANDLE REMAINED ON. NO ACTUAL FIRE DISCOVERED; SO CAPT AND FO DECIDED NOT TO EVAC THE PAX AND TAXIED BACK TO A GATE FOR NORMAL PAX DEPLANING (IE; JETWAY). TOTAL TIME AIRBORNE (INFLT) WAS 8 MINS. PA ANNOUNCEMENTS WERE MADE 3 TIMES TO PAX. FIRST PA ANNOUNCEMENT WAS MADE INFLT ON MODIFIED DOWNWIND TO RWY 22 AT 3000 FT; PAX WERE TOLD WE HAD A MECHANICAL PROB AND WOULD LAND BACK AT MSP. THE CAPT'S BIGGEST FEAR WAS A PAX INITIATED EVAC. ON LNDG ROLLOUT; PAX WERE INFORMED OF OUR ACTUAL EMER INDICATIONS AND ACTIONS WITH NO ACTUAL FIRE DISCOVERED. THE FINAL ANNOUNCEMENT EXPLAINED OUR DECISION TO TAXI BACK TO THE GATE TO OFFLOAD PAX. CREW PERFORMANCE WAS HIGH WITH FO DOING ALL THE FLYING (MAINTAINING ACFT CTL). CAPT MAKING ALL RADIO CALLS; EXECUTING IMMEDIATE ACTIONS; REFERRING TO CHKLIST; TALKING TO FLT ATTENDANTS; AND COM BTWN CAPT/FO WAS OPEN ABOUT ANALYZING SIT; KEEPING PAX INFORMED; AND DEPLANING PAX NORMALLY.