A B727-200 IN CLB AT 16000 FT DECLARED AN EMER; DUMPED FUEL AND DIVERTED DUE TO A LOWER AFT BODY OVERHEAT WARNING LIGHT. CAUSE UNKNOWN BUT CHRONIC PROB.

Narrative

DURING CLB; THE FE ANNOUNCED THE 'LOWER AFT BODY OVERHEAT' LIGHT WAS ILLUMINATED; INDICATING A BLEED AIR LEAK IN THE AREA BTWN THE KEEL BEAM AND THE AFT STAIR COMPARTMENT. THE CAPT CONTINUED TO FLY WHILE I WORKED THE CHKLIST WITH THE FE AND RESPONDED TO RADIO CALLS. THE CHKLIST IS DESIGNED TO ISOLATE WHICH ENG IS PROVIDING THE LEAKING BLEED AIR BY EXTINGUISHING THE OVERHEAT LIGHT. HOWEVER; WE WERE UNABLE TO EXTINGUISH THE LIGHT BY FOLLOWING THE CHKLIST PROCS. WE THEN DECLARED AN EMER AND ASKED FOR VECTORS BACK TO MINNEAPOLIS FOR LNDG. AS WE BEGAN DSNDING AND TURNING TOWARDS MINNEAPOLIS; THE FE NOTED THE ACFT WAS APPROX 15000 LBS OVER MAX LNDG WT. IT WAS THEN DECIDED THAT WE SHOULD DUMP FUEL TO GET DOWN TO LNDG WT. AT OUR REQUEST ATC APPROVED FUEL DUMPING AT OUR PRESENT POS AND TO CONTINUE AS LONG AS NEEDED. A FEW MINS AFTER FUEL DUMPING HAD BEEN INITIATED; THE FE ANNOUNCED THE LOWER AFT BODY OVERHEAT LIGHT HAD EXTINGUISHED. AS WE CONTINUED DSNDING; WE NOTED THE ADVISORY ITEM OF THE FUEL DUMPING CHKLIST WHICH RECOMMENDS AGAINST DUMPING FUEL BELOW 6000 FT AGL. AS WE APCHED THIS ALT; THE FE STATED THE ACFT WAS NOW WITHIN 3000 LBS OF MAX LNDG WT. WE THEN DECIDED TO TERMINATE FUEL DUMPING DUE TO THE CLOSE POS TO THE ARPT AND BEGINNING TO SLOW THE ACFT FOR CONFIGN FOR LNDG. WE FELT LNDG SLIGHTLY OVERWT WAS BETTER THAN DUMPING FUEL DURING A POSSIBLE OVERHEAT CONDITION IN THE AFT OF THE AIRPLANE. THE CAPT LANDED THE ACFT VERY SMOOTHLY WITH THE EMER VEHICLES STANDING BY AT THE SIDE OF THE RWY. WE TAXIED TO THE GATE WITHOUT FURTHER INCIDENT. CALLBACK CONVERSATION WITH THE RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE AIRCRAFT WAS A B727-200 AND THIS RETURN TO THE FIELD WAS THE SECOND TIME FOR THIS LOWER BODY OVERHEAT PROBLEM. THE RPTR SAID THE DAY BEFORE THIS AIRCRAFT MADE A EMER LNDG WITH THE SAME PROB. THE RPTR STATED THE CAUSE OF THE LOWER BODY OVERHEAT WARNING AND THE POSITIVE MAINTENANCE FIX IS UNKNOWN. CALLBACK CONVERSATION WITH RPTR ACN 444320 THE RPTR STATED THE CAUSE OF THE LOWER BODY WARNING IS UNKNOWN AS NO FEEDBACK WAS RECEIVED FROM MAIN ON THE CORRECTIVE ACTION.