A320 CREW MAKES EMER DSCNT DUE TO CABIN PRESSURIZATION PROBS.

Narrative

IN ZZZ AIRPLANE VERY HOT UPON ARR THAT MORNING. STARTED APU TO COOL IT DOWN; BUT TEMP IN CABIN NEVER DROPPED BELOW 82 DEGS. PUSHED BACK AND STARTED ENGS; AIRPLANE REMAINED VERY HOT AND ON TAXI OUT HAD A R PACK FAULT. RESET R PACK. L PACK WAS DEFERRED FOR FLT. NORMAL TKOF FROM RWY 32L; CABIN STILL NOT COOLING DOWN. CABIN TEMP 82 DEGS; INLET AIR TO CABIN 88 DEGS. NOTIFIED MAINT FOR HELP WITH CABIN TEMP. RESET CIRCUIT BREAKERS RECOMMENDED BY MAINT AND TEMP STARTED TO COME DOWN A FEW DEGS. NOTICED THAT R PACK HAD LOW OUTFLOW. NOT LONG AFTER LEVELOFF AT 31000 FT; NOTICED THAT CABIN PRESSURIZATION WAS CLBING; REQUESTED LOWER FROM CTR AND STARTED DSCNT TO 27000 FT; CABIN STILL UNCONTROLLABLE AND CLBING; AT 10000 FT CABIN ALT DONNED OXYGEN MASKS AND DECLARED EMER. STARTED EMER DSCNT TO 10000 FT. FO PERFORMED ECAM PROCS FOR 'EXCESSIVE CABIN PRESSURE?' DSCNT WAS NORMAL TO 10000 FT AND REGAINED CTL OF CABIN PRESSURE. FLT ATTENDANTS AND PAX WERE SEATED AND SITUATION WAS EXPLAINED TO BOTH. NEVER HAD A PACK FAULT ON R SIDE. R SIDE PACK REMAINED IN LOW FLOW. NOTIFIED DISPATCH AND MAINT OF EMER AND ACFT PROBS. CABIN TEMP ON REMAINDER OF FLT; WELL OVER 85 DEGS. SUPPLEMENTAL INFO FROM ACN 703817: INITIAL INDICATIONS WERE COOLING PROBS ON THE GND AND INFLT. PACK NEVER FULLY BEGAN COOLING PROCESS. CABIN TEMP 88 DEGS. PACK INDICATED LOW FLOW ENTIRE TIME; EVEN WITH HIGH SELECTED. MAINT HAD US PULL SOME ZONE TEMP CTLR CIRCUIT BREAKERS WITH NO DRAMATIC EFFECT. DURING EMER WE NOTED THE OUTFLOW VALVE FULLY CLOSED; PACK WAS SIMPLY NOT ABLE TO KEEP ACFT PRESSURIZED. ACFT HAD BEEN DISPATCHED WITH ONLY 1 OPERATIVE PACK; SO NO BACKUP. FINAL DSCNT WAS TO 6000 FT MSL EFFECTIVELY REDUCING CABIN ALT TO THAT LEVEL; OUR OXYGEN MASKS WERE THEN REMOVED; AND WE PROCEEDED TO ZZZ2.