B737-300 flight crew experienced loss of cabin pressure. They descended to 10;000 ft and diverted to...

Narrative:

On the ground; we had an MEL which led to numerous procedural events. We could not use APU air for takeoff and [had to perform] a bleeds off takeoff. Thus an unpressurized procedure was required and complied with from the aom. At 3;000 ft; we reconfigured the aircraft to pressurized flight--packs were auto; bleeds turned on; pressurizations system to auto; and cruise altitude reselected to 34;000 ft. The aircraft began pressurizing correctly. Passing through 10;000 ft; the climb check was accomplished. The pressurization was normal at cabin altitude of 3;000 ft. Passing 29;000 ft; we got a cabin altitude warning horn; and immediate complied with the abnormal pressurization memory items by putting our masks on and establishing communication. We immediately thought of the MEL; and double-checked that we had all the switches in the correct position. Finding everything correct; our next thought was getting down to 10;000 ft. I went straight to the emergency descent checklist; but failed to complete the entire abnormal pressurization checklist; which directs us to go to manual and close the outflow valve. We descended to 10;000 ft; and coordinated a divert.

Original NASA ASRS Text

Title: B737-300 flight crew experienced loss of cabin pressure. They descended to 10;000 FT and diverted to the nearest suitable airport.

Narrative: On the ground; we had an MEL which led to numerous procedural events. We could not use APU air for takeoff and [had to perform] a bleeds off takeoff. Thus an unpressurized procedure was required and complied with from the AOM. At 3;000 FT; we reconfigured the aircraft to pressurized flight--packs were auto; bleeds turned on; pressurizations system to auto; and cruise altitude reselected to 34;000 FT. The aircraft began pressurizing correctly. Passing through 10;000 FT; the climb check was accomplished. The pressurization was normal at cabin altitude of 3;000 FT. Passing 29;000 FT; we got a Cabin Altitude Warning horn; and immediate complied with the abnormal pressurization memory items by putting our masks on and establishing communication. We immediately thought of the MEL; and double-checked that we had all the switches in the correct position. Finding everything correct; our next thought was getting down to 10;000 FT. I went straight to the Emergency Descent Checklist; but failed to complete the entire Abnormal Pressurization Checklist; which directs us to go to manual and close the outflow valve. We descended to 10;000 FT; and coordinated a divert.

Data retrieved from NASA's ASRS site as of July 2013 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	1019946
Time
Date	201206
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Pressurization System
Person 1
Function	First Officer
Experience	Flight Crew Last 90 Days 178
Person 2
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 229
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy

B737-300 flight crew experienced loss of cabin pressure. They descended to 10;000 ft and diverted to the nearest suitable airport.