Date: 201212
Local time of day: 1801-2400
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Pressurization System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; General Declared Emergency
Contributing factors: Human Factors; Aircraft
Primary problem: Aircraft

Narrative: Cruising at FL380 and start to step down for our approach. Step down to FL360 then FL320. While at FL320 notice on ECAM that cabin altitude is reading >9;000 feet and pulsing green then I believe steady amber. As cabin altitude continues to climb cabin altitude displays red followed by CAB PR EXCESS CAB ALT ECAM (my recollection). Donned masks and requested lower from ATC. First Officer flying and Captain runs through ECAM checklist. Recall 3 or 4 steps. CREW OXY MASK - ON; ATC - NOTIFY; PAX OXY MASKS - MAN ON. Followed ECAM. ATC asks if we are declaring an emergency and at that point we state affirmative. They give us direct to destination as we decide on alternates. First Officer continues to step down. Recall at one point Safety Valve Position drives open then closes. Feel a cool refreshing air flow. At approximately 16;000 feet enter into FM and this suggests trying CABIN PRESS MODE SEL to MAN. Doesn't appear to respond. Continue our descent and request a phone patch to Dispatch. Also ACARS Dispatch stating that we have declared an emergency and request possible alternate airports if necessary. Response from Dispatch is that destination looks good. Once through 10;000 feet; remove oxygen masks and then level off at 8;000 feet. Notice cabin altitude is equal to aircraft altitude. Establish communications with Purser; passengers and Dispatch. Decide not to Maintenance as we are closing in on destination and everything is under control. First Officer briefs approach and lands uneventfully.


Second narrative: We were getting step down descents; FL380; FL360; and was now level at FL320. ECAM for Cabin Pressure. Saw cabin pressure rising over 8;000 feet; both pilots donned O2 masks; Captain worked ECAM; [and] I continued to fly. Cabin pressure continued to rise; we declared emergency and requested lower. Aircraft continued to slowly depressurize. Captain continued with ECAM (including passenger mask deployment); QRC; and into the FM. Captain commented that Manual Pressurization did not seem to be working well either. I was working with ATC to get lower as [soon as] possible; we were over the mountains so step downs came in intervals; first FL200; then 16;000 feet; then 14;000 feet; and eventually down to 8;000 feet. Captain was working with Purser and Dispatch; we agreed on continuing to destination as the aircraft was now able to be flown de-pressurized. At one point during descent; aircraft began to over pressurize and safety valve opened. At 8;000 feet we removed O2 masks; Captain and I got back on the same page; reviewed approach; finished checklists; conferred and confirmed everything that needed to be done had been done; and concluded with an uneventful ILS in VMC conditions. Autopilot was engaged until the outer marker. On taxi in; ECAM calling to make sure cabin was depressurized; I was able to manually open outflow valve at this point.


Synopsis: A320 flight crew experiences a gradual loss of cabin pressurization during initial descent for landing with the First Officer the pilot flying. ECAM actions are complied with when cabin altitude exceeds 10;000 feet and manual pressurization is attempted. At one point during descent; aircraft began to over pressurize and safety valve opens. Flight continues to destination for normal landing and during taxi in ECAM alerts to cabin being pressurized on the ground.