A B737-300 flight crew made a timely emergency descent and diverted to a nearby airport when they we...

Attributes
ACN	930067
Time
Date	201101
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Pressurization System
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Flight Engineer Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 120 Flight Crew Total 28000 Flight Crew Type 24000
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

In cruise at FL330 the cabin altitude warning horn came on. Put mask on and could not control the cabin with auto or standby. Asked ATC for lower due to a pressurization problem and were cleared down to 10;000. ATC asked us where we wanted to go and we said ZZZ. I checked with the flight attendants who advised they and the passengers were fine and the masks didn't drop. I told them we had a pressurization problem but everything was ok and we were diverting and would be there in 20 minutes for a precautionary landing. I then made a PA to the passengers.ATC asked if we needed crash trucks or assistance. We said everything was fine and we did not. We landed with no problem; taxied to gate; wrote it up and talked to maintenance.

Original NASA ASRS Text

Title: A B737-300 flight crew made a timely emergency descent and diverted to a nearby airport when they were unable to control the cabin altitude with either the automatic or standby modes.

Narrative: In cruise at FL330 the Cabin Altitude Warning Horn came on. Put mask on and could not control the cabin with auto or standby. Asked ATC for lower due to a pressurization problem and were cleared down to 10;000. ATC asked us where we wanted to go and we said ZZZ. I checked with the Flight Attendants who advised they and the passengers were fine and the masks didn't drop. I told them we had a pressurization problem but everything was OK and we were diverting and would be there in 20 minutes for a precautionary landing. I then made a PA to the passengers.ATC asked if we needed crash trucks or assistance. We said everything was fine and we did NOT. We landed with no problem; taxied to gate; wrote it up and talked to Maintenance.

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.