MD80 crew had cabin pressurization climb uncontrollably as the aircraft began descent from FL370.

Attributes
ACN	567868
Time
Date	200212
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	msl bound lower : 6000 msl bound upper : 37000
Aircraft 1
Controlling Facilities	artcc : zmp.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	567868
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : cabin pressurization indication. cabin rate of clb other flight crewa other flight crewb
Resolutory Action	aircraft : equipment problem dissipated controller : issued new clearance controller : provided flight assist flight crew : overrode automation flight crew : declared emergency other
Consequence	other other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Cruising at FL370, cabin was chilly, but ok. Started a descent to FL330 per ATC. Cabin pressure started climbing. Requested lower altitude. Cabin altitude climbed faster at about 1500-2000 FPM. Accomplished depressurization checklist and initiated emergency descent. Descended to 6000 ft because cabin noise was very loud around 10000 ft. Packs reinstated shortly thereafter. Flight continued to ord normally. Emergency was declared but crash fire rescue equipment was canceled since aircraft was normal operation below 10000 ft.

Original NASA ASRS Text

Title: MD80 CREW HAD CABIN PRESSURIZATION CLB UNCONTROLLABLY AS THE ACFT BEGAN DSCNT FROM FL370.

Narrative: CRUISING AT FL370, CABIN WAS CHILLY, BUT OK. STARTED A DSCNT TO FL330 PER ATC. CABIN PRESSURE STARTED CLBING. REQUESTED LOWER ALT. CABIN ALT CLBED FASTER AT ABOUT 1500-2000 FPM. ACCOMPLISHED DEPRESSURIZATION CHKLIST AND INITIATED EMER DSCNT. DSNDED TO 6000 FT BECAUSE CABIN NOISE WAS VERY LOUD AROUND 10000 FT. PACKS REINSTATED SHORTLY THEREAFTER. FLT CONTINUED TO ORD NORMALLY. EMER WAS DECLARED BUT CFR WAS CANCELED SINCE ACFT WAS NORMAL OP BELOW 10000 FT.

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.