An MD80 flight crew reported that they experienced a pressurization failure during a flight from dfw...

Attributes
ACN	629661
Time
Date	200409
Day	Wed
Place
Locale Reference	airport : sat.airport
State Reference	TX
Altitude	msl single value : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu.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	629661
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	630664
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action flight crew : declared emergency
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

While at cruise at FL350, the #4 flight attendant called the cockpit and asked if we could warm up the back a bit. The first officer made a small adjustment to the right temperature control, then checked the cabin and supply temperatures. The cabin temperature was normal, but the supply temperature was pepped at 150 degrees. The first officer then adjusted the controller to a cooler setting, watching the valve move to a cooler position. The supply temperature remained pegged at 150 degrees. Then the first officer noticed both flow gauges showed zero flow and the cabin altitude was rising through approximately 8500 ft. We immediately requested a descent from center. Center replied with 'stand by.' at this time we declared an emergency and informed center we were descending because of loss of pressurization. Cabin altitude at this time was approximately 9500 ft when we initiated the emergency descent procedures. Cabin altitude continued to climb during our descent until we reached equilibrium at approximately 15000 ft cabin altitude, then the cabin descended with the airplane. The cabin oxygen masks did deploy at approximately 14000 ft cabin altitude. We continued descent to an uneventful landing at san antonio, taxied to a gate, where all passenger deplaned under their own power and appeared calm and unharmed.

Original NASA ASRS Text

Title: AN MD80 FLT CREW RPTED THAT THEY EXPERIENCED A PRESSURIZATION FAILURE DURING A FLT FROM DFW TO SAT, WHICH CAUSED THEM TO DECLARE AN EMER WITH ZHU AFTER WHICH THEY MADE A NORMAL LNDG AT SAT.

Narrative: WHILE AT CRUISE AT FL350, THE #4 FLT ATTENDANT CALLED THE COCKPIT AND ASKED IF WE COULD WARM UP THE BACK A BIT. THE FO MADE A SMALL ADJUSTMENT TO THE R TEMP CTL, THEN CHKED THE CABIN AND SUPPLY TEMPS. THE CABIN TEMP WAS NORMAL, BUT THE SUPPLY TEMP WAS PEPPED AT 150 DEGS. THE FO THEN ADJUSTED THE CONTROLLER TO A COOLER SETTING, WATCHING THE VALVE MOVE TO A COOLER POS. THE SUPPLY TEMP REMAINED PEGGED AT 150 DEGS. THEN THE FO NOTICED BOTH FLOW GAUGES SHOWED ZERO FLOW AND THE CABIN ALT WAS RISING THROUGH APPROX 8500 FT. WE IMMEDIATELY REQUESTED A DSCNT FROM CTR. CTR REPLIED WITH 'STAND BY.' AT THIS TIME WE DECLARED AN EMER AND INFORMED CTR WE WERE DSNDING BECAUSE OF LOSS OF PRESSURIZATION. CABIN ALT AT THIS TIME WAS APPROX 9500 FT WHEN WE INITIATED THE EMER DSCNT PROCS. CABIN ALT CONTINUED TO CLB DURING OUR DSCNT UNTIL WE REACHED EQUILIBRIUM AT APPROX 15000 FT CABIN ALT, THEN THE CABIN DSNDED WITH THE AIRPLANE. THE CABIN OXYGEN MASKS DID DEPLOY AT APPROX 14000 FT CABIN ALT. WE CONTINUED DSCNT TO AN UNEVENTFUL LNDG AT SAN ANTONIO, TAXIED TO A GATE, WHERE ALL PAX DEPLANED UNDER THEIR OWN PWR AND APPEARED CALM AND UNHARMED.

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.

An MD80 flight crew reported that they experienced a pressurization failure during a flight from dfw to sat, which caused them to declare an emergency with ZHU after which they made a normal landing at sat.