MD80 pressurization system fails at FL280.

Attributes
ACN	703686
Time
Date	200607
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zzz.artcc
State Reference	US
Altitude	msl single value : 33000
Environment
Flight Conditions	IMC
Weather Elements	Ice
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	703686
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment : altitude alert
Resolutory Action	flight crew : declared emergency
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

At just when our meals were being delivered the cabin altitude warning came on. Cabin altitude 10000+ ft and climbing at 300 FPM. We put our masks on then right ice protect temperature high came on. We closed the outflow valve manually and turned off the right airfoil ice protection. Cabin climbing at maximum rate we declared an emergency and started down. Both packs had tripped. Passing through around FL280 we started to regain cabin pressure. We leveled off at FL220 out of icing and continued.

Original NASA ASRS Text

Title: MD80 PRESSURIZATION SYS FAILS AT FL280.

Narrative: AT JUST WHEN OUR MEALS WERE BEING DELIVERED THE CABIN ALT WARNING CAME ON. CABIN ALT 10000+ FT AND CLBING AT 300 FPM. WE PUT OUR MASKS ON THEN R ICE PROTECT TEMP HIGH CAME ON. WE CLOSED THE OUTFLOW VALVE MANUALLY AND TURNED OFF THE R AIRFOIL ICE PROTECTION. CABIN CLBING AT MAX RATE WE DECLARED AN EMER AND STARTED DOWN. BOTH PACKS HAD TRIPPED. PASSING THROUGH AROUND FL280 WE STARTED TO REGAIN CABIN PRESSURE. WE LEVELED OFF AT FL220 OUT OF ICING AND CONTINUED.

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.