An MD80 flight crew experienced cabin depressurization when the single pressure controller they were...

Attributes
ACN	731146
Time
Date	200703
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 29000
Environment
Weather Elements	Rain Thunderstorm Turbulence
Light	Night
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	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	731146
Person 2
Affiliation	company : air carrier
Function	flight attendant : on duty
Experience	flight attendant time airline total : 16 flight attendant time total : 16 flight attendant time type : 20
ASRS Report	731552
Events
Anomaly	aircraft equipment problem : critical inflight encounter : weather
Independent Detector	aircraft equipment other aircraft equipment : cabin alt ind
Resolutory Action	flight crew : declared emergency flight crew : diverted to another airport
Supplementary
Problem Areas	Weather Aircraft
Primary Problem	Aircraft

Narrative:

Aircraft was dispatched with only 1 pressurization controller. It failed climbing through 29000 ft. There were cumulo nimbus in our area we started an immediate descent. We complied with red book as we continued the descent to a lower altitude while in manual pressurization. As we descended through 23000 ft; the cabin altitude was going through 9000 ft and climbing 2000 FPM. At that time; I instructed the first officer to manually deploy the passenger oxygen masks so that the flight attendants would maintain consciousness while giving instructions to the passenger. We were able to arrest the pressurization by 19000 ft but had to stay at that altitude for 10 more mins to stay above thunderstorms. Of course; we declared an emergency; and decided to divert into ZZZ. Once again; not a good idea going WX with 1 pressurization controller. Supplemental information from acn 731552: 1) problem was known before takeoff #1 pack was out. We were told that a 30% chance #2 would go out.) in our briefing the details were not discussed about the plan of action if it did go out.

Original NASA ASRS Text

Title: AN MD80 FLT CREW EXPERIENCED CABIN DEPRESSURIZATION WHEN THE SINGLE PRESSURE CONTROLLER THEY WERE DISPATCHED WITH FAILED.

Narrative: ACFT WAS DISPATCHED WITH ONLY 1 PRESSURIZATION CTLR. IT FAILED CLBING THROUGH 29000 FT. THERE WERE CUMULO NIMBUS IN OUR AREA WE STARTED AN IMMEDIATE DSCNT. WE COMPLIED WITH RED BOOK AS WE CONTINUED THE DSCNT TO A LOWER ALT WHILE IN MANUAL PRESSURIZATION. AS WE DSNDED THROUGH 23000 FT; THE CABIN ALT WAS GOING THROUGH 9000 FT AND CLBING 2000 FPM. AT THAT TIME; I INSTRUCTED THE FO TO MANUALLY DEPLOY THE PAX OXYGEN MASKS SO THAT THE FLT ATTENDANTS WOULD MAINTAIN CONSCIOUSNESS WHILE GIVING INSTRUCTIONS TO THE PAX. WE WERE ABLE TO ARREST THE PRESSURIZATION BY 19000 FT BUT HAD TO STAY AT THAT ALT FOR 10 MORE MINS TO STAY ABOVE TSTMS. OF COURSE; WE DECLARED AN EMER; AND DECIDED TO DIVERT INTO ZZZ. ONCE AGAIN; NOT A GOOD IDEA GOING WX WITH 1 PRESSURIZATION CTLR. SUPPLEMENTAL INFO FROM ACN 731552: 1) PROB WAS KNOWN BEFORE TKOF #1 PACK WAS OUT. WE WERE TOLD THAT A 30% CHANCE #2 WOULD GO OUT.) IN OUR BRIEFING THE DETAILS WERE NOT DISCUSSED ABOUT THE PLAN OF ACTION IF IT DID GO OUT.

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.

An MD80 flight crew experienced cabin depressurization when the single pressure controller they were dispatched with failed.