A pressurization problem caused an air carrier medium large transport to return land.

Attributes
ACN	287236
Time
Date	199410
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : slc
State Reference	UT
Altitude	msl bound lower : 13000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zlc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 5000 flight time type : 1000
ASRS Report	287236
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : exited adverse environment none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

During cruise, about FL300, we heard an unusual sound. The cabin rate of climb was pegged at 4000 FPM. The pressurization outflow valve was completely closed. We were losing cabin pressure. I advised ZLC of our problem and requested an immediate descent. We descended to about 13000 ft. The minimum vectoring altitude was about 14000 ft. Since we were VMC, we went VFR to 13000 ft. I requested clearance back to salt lake city. We remained in VMC conditions at a minimum altitude. The highest our cabin altitude reached was 13000 ft. After our arrival, it was discovered that the forward cargo compartment door seal had failed.

Original NASA ASRS Text

Title: A PRESSURIZATION PROB CAUSED AN ACR MLG TO RETURN LAND.

Narrative: DURING CRUISE, ABOUT FL300, WE HEARD AN UNUSUAL SOUND. THE CABIN RATE OF CLB WAS PEGGED AT 4000 FPM. THE PRESSURIZATION OUTFLOW VALVE WAS COMPLETELY CLOSED. WE WERE LOSING CABIN PRESSURE. I ADVISED ZLC OF OUR PROB AND REQUESTED AN IMMEDIATE DSCNT. WE DSNDED TO ABOUT 13000 FT. THE MINIMUM VECTORING ALT WAS ABOUT 14000 FT. SINCE WE WERE VMC, WE WENT VFR TO 13000 FT. I REQUESTED CLRNC BACK TO SALT LAKE CITY. WE REMAINED IN VMC CONDITIONS AT A MINIMUM ALT. THE HIGHEST OUR CABIN ALT REACHED WAS 13000 FT. AFTER OUR ARR, IT WAS DISCOVERED THAT THE FORWARD CARGO COMPARTMENT DOOR SEAL HAD FAILED.

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.