MD80 pack tripped while operating with the other pack deferred. Flight descended below 8000 ft and d...

Attributes
ACN	765662
Time
Date	200712
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 24000
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 : captain oversight : pic
ASRS Report	765662
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	765228
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : landed as precaution flight crew : diverted to another airport
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

MEL to single pack operation. Flying along at 24000 ft en route to ZZZ1. Flight attendant just handed our lunch tray to us and said warm it up a bit. First officer in automatic temperature mode adjusted up a little. Ate a couple of bites of food and my ears popped. Looked up to overhead to see cabin climbing. Cabin altitude was at 4200 ft. Very low cause we were restr to 24000 ft. Looked at outflow valve and it was fully closed. ATC gave us lower; did rapid depressurization procedure and descended quickly to 8000 ft. Diverted to ZZZ. Suspect pack tripped.

Original NASA ASRS Text

Title: MD80 PACK TRIPPED WHILE OPERATING WITH THE OTHER PACK DEFERRED. FLT DESCENDED BELOW 8000 FT AND DIVERTED.

Narrative: MEL TO SINGLE PACK OP. FLYING ALONG AT 24000 FT ENRTE TO ZZZ1. FLT ATTENDANT JUST HANDED OUR LUNCH TRAY TO US AND SAID WARM IT UP A BIT. FO IN AUTO TEMP MODE ADJUSTED UP A LITTLE. ATE A COUPLE OF BITES OF FOOD AND MY EARS POPPED. LOOKED UP TO OVERHEAD TO SEE CABIN CLBING. CABIN ALT WAS AT 4200 FT. VERY LOW CAUSE WE WERE RESTR TO 24000 FT. LOOKED AT OUTFLOW VALVE AND IT WAS FULLY CLOSED. ATC GAVE US LOWER; DID RAPID DEPRESSURIZATION PROC AND DSNDED QUICKLY TO 8000 FT. DIVERTED TO ZZZ. SUSPECT PACK TRIPPED.

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.

MD80 pack tripped while operating with the other pack deferred. Flight descended below 8000 ft and diverted.