A320 crew makes emergency descent due to cabin pressurization problems.

Attributes
ACN	703816
Time
Date	200607
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zzz.artcc
State Reference	US
Altitude	msl single value : 31000
Environment
Flight Conditions	IMC
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 230 flight time total : 13650 flight time type : 5500
ASRS Report	703816
Person 2
Affiliation	company : air carrier
Experience	flight time last 90 days : 110 flight time total : 10000 flight time type : 5000
ASRS Report	703817
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : declared emergency
Supplementary
Problem Areas	Company Maintenance Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

In ZZZ airplane very hot upon arrival that morning. Started APU to cool it down; but temperature in cabin never dropped below 82 degrees. Pushed back and started engines; airplane remained very hot and on taxi out had a right pack fault. Reset right pack. Left pack was deferred for flight. Normal takeoff from runway 32L; cabin still not cooling down. Cabin temperature 82 degrees; inlet air to cabin 88 degrees. Notified maintenance for help with cabin temperature. Reset circuit breakers recommended by maintenance and temperature started to come down a few degrees. Noticed that right pack had low outflow. Not long after leveloff at 31000 ft; noticed that cabin pressurization was climbing; requested lower from center and started descent to 27000 ft; cabin still uncontrollable and climbing; at 10000 ft cabin altitude donned oxygen masks and declared emergency. Started emergency descent to 10000 ft. First officer performed ECAM procedures for 'excessive cabin pressure?' descent was normal to 10000 ft and regained control of cabin pressure. Flight attendants and passenger were seated and situation was explained to both. Never had a pack fault on right side. Right side pack remained in low flow. Notified dispatch and maintenance of emergency and aircraft problems. Cabin temperature on remainder of flight; well over 85 degrees. Supplemental information from acn 703817: initial indications were cooling problems on the ground and in-flight. Pack never fully began cooling process. Cabin temperature 88 degrees. Pack indicated low flow entire time; even with high selected. Maintenance had us pull some zone temperature controller circuit breakers with no dramatic effect. During emergency we noted the outflow valve fully closed; pack was simply not able to keep aircraft pressurized. Aircraft had been dispatched with only 1 operative pack; so no backup. Final descent was to 6000 ft MSL effectively reducing cabin altitude to that level; our oxygen masks were then removed; and we proceeded to ZZZ2.

Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of January 2009 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.