B737 cabin altitude warning horn alerted passing FL310 in the climb. Oxygen masks are donned and an ...

Narrative:

Departed and in the climb out of FL310 for FL320 we got the intermittent warning horn. O2 masks were donned and we observed that the cabin altitude was steadily climbing toward 10;000 ft. It was in the 9;000 ft range at that time. [We] instructed ATC that we needed an immediate descent. Initially we were cleared to FL240 and passing FL290; we requested continued descent to 10;000 ft. Advised ATC of our pressurization problem and asked for nearest airports. The captain decided an airport that was most suitable at about 130 miles. I completed the QRH and captain advised flight attendants. Stabilized at 10;000 ft; the cabin maintained pressurization. The cabin altitude did not exceed 10;000 ft. We advised dispatch and airport operations and made uneventful landing.

Original NASA ASRS Text

Title: B737 cabin altitude warning horn alerted passing FL310 in the climb. Oxygen masks are donned and an immediate descent is requested. The cabin altitude did not exceed 10;000 FT during the descent but the crew diverted to a suitable airport.

Narrative: Departed and in the climb out of FL310 for FL320 we got the intermittent warning horn. O2 masks were donned and we observed that the cabin altitude was steadily climbing toward 10;000 FT. It was in the 9;000 FT range at that time. [We] instructed ATC that we needed an immediate descent. Initially we were cleared to FL240 and passing FL290; we requested continued descent to 10;000 FT. Advised ATC of our pressurization problem and asked for nearest airports. The Captain decided an airport that was most suitable at about 130 miles. I completed the QRH and Captain advised flight attendants. Stabilized at 10;000 FT; the cabin maintained pressurization. The cabin altitude did not exceed 10;000 FT. We advised Dispatch and Airport Operations and made uneventful landing.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	957020
Time
Date	201107
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Flight Phase	Climb
Component
Aircraft Component	Pressurization System
Person 1
Function	First Officer
Experience	Flight Crew Last 90 Days 234
Events
Anomaly	Aircraft Equipment Problem Critical

B737 cabin altitude warning horn alerted passing FL310 in the climb. Oxygen masks are donned and an immediate descent is requested. The cabin altitude did not exceed 10;000 ft during the descent but the crew diverted to a suitable airport.