Narrative:

While at cruise altitude, the lower aft body overheat light illuminated. The engine bleed confign at the time was #1 engine bleed open, left #2 engine bleed closed, right #2 engine bleed open, and #3 engine bleed closed. The checklist was accomplished. Closing the cargo heat outflow valve did not change the situation. 2 mins after closing the #1 engine bleed, the lower aft body overheat light began to flash. It never extinguished. The #1 engine bleed was selected on again and the right #2 engine bleed was moved to the off position. After 2 mins, the lower aft body overheat light began to flash. Thereafter, the throttles were retarded to start a descent. After retarding the throttles, the lower aft body overheat light extinguished. At this point, the #1 engine bleed was open and the left pack was operating. The left pack would not maintain cabin pressurization and as the cabin altitude approached 10000 ft, the aforementioned descent was accomplished. At 12000 ft, the cabin stabilized at 8000 ft. An emergency was declared, and we flew direct to sdq. An uneventful overweight landing (155000 pounds) was made at sdq. I flew the same aircraft (#xyz) on aug/xa/00 and had the same problem. The only difference was this time the lower aft body overheat light flashed, as opposed to remaining illuminated until extinguished by proper bleed selection during the checklist.

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Original NASA ASRS Text

Title: A B727-200 IN CRUISE AT FL310 DECLARED AN EMER AND DIVERTED DUE TO AFT LOWER BODY OVERHEAT WARNING -- A RECURRING PROB.

Narrative: WHILE AT CRUISE ALT, THE LOWER AFT BODY OVERHEAT LIGHT ILLUMINATED. THE ENG BLEED CONFIGN AT THE TIME WAS #1 ENG BLEED OPEN, L #2 ENG BLEED CLOSED, R #2 ENG BLEED OPEN, AND #3 ENG BLEED CLOSED. THE CHKLIST WAS ACCOMPLISHED. CLOSING THE CARGO HEAT OUTFLOW VALVE DID NOT CHANGE THE SIT. 2 MINS AFTER CLOSING THE #1 ENG BLEED, THE LOWER AFT BODY OVERHEAT LIGHT BEGAN TO FLASH. IT NEVER EXTINGUISHED. THE #1 ENG BLEED WAS SELECTED ON AGAIN AND THE R #2 ENG BLEED WAS MOVED TO THE OFF POS. AFTER 2 MINS, THE LOWER AFT BODY OVERHEAT LIGHT BEGAN TO FLASH. THEREAFTER, THE THROTTLES WERE RETARDED TO START A DSCNT. AFTER RETARDING THE THROTTLES, THE LOWER AFT BODY OVERHEAT LIGHT EXTINGUISHED. AT THIS POINT, THE #1 ENG BLEED WAS OPEN AND THE L PACK WAS OPERATING. THE L PACK WOULD NOT MAINTAIN CABIN PRESSURIZATION AND AS THE CABIN ALT APCHED 10000 FT, THE AFOREMENTIONED DSCNT WAS ACCOMPLISHED. AT 12000 FT, THE CABIN STABILIZED AT 8000 FT. AN EMER WAS DECLARED, AND WE FLEW DIRECT TO SDQ. AN UNEVENTFUL OVERWT LNDG (155000 LBS) WAS MADE AT SDQ. I FLEW THE SAME ACFT (#XYZ) ON AUG/XA/00 AND HAD THE SAME PROB. THE ONLY DIFFERENCE WAS THIS TIME THE LOWER AFT BODY OVERHEAT LIGHT FLASHED, AS OPPOSED TO REMAINING ILLUMINATED UNTIL EXTINGUISHED BY PROPER BLEED SELECTION DURING THE CHKLIST.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.