A B737-300 flight crew experienced a loss of cabin pressure climbing through FL320. They declared an...

Narrative:

The previous crew reported problems with the a autopilot and with the pressurization system. The a autopilot system was deferred. The pressurization controller was swapped. As a result we departed uneventfully approximately two hours late.during the climb we noticed the TCAS started to intermittently fail. Shortly thereafter; while climbing through FL320; we heard the cabin altitude warning horn. We quickly accomplished the memory and QRH items; declared an emergency and began an emergency descent. On the descent and approach we received additional warnings such as 'low idle' and 'speed brake do not deploy.'as soon as we could; the captain called the flight attendants to advise them of our situation. Fortunately we were able to get to a lower altitude before the passenger masks deployed. We transferred control of the airplane and discussed making a PA. However; we were at 2000 feet; and decided to do it when we landed. Once landed; the first officer made a PA explaining what had occurred. We landed overweight uneventfully and taxied to the gate. Finally; the captain called dispatch; sod; maintenance control; and the chief pilot on call. During a conversation with maintenance control the captain was advised that the most likely cause of our pressurization controller fault and other multiple failures was a faulty air/ground sensor.

Original NASA ASRS Text

Title: A B737-300 flight crew experienced a loss of cabin pressure climbing through FL320. They declared an emergency; descended and diverted to a nearby airport.

Narrative: The previous crew reported problems with the A autopilot and with the pressurization system. The A autopilot system was deferred. The pressurization controller was swapped. As a result we departed uneventfully approximately two hours late.During the climb we noticed the TCAS started to intermittently fail. Shortly thereafter; while climbing through FL320; we heard the Cabin Altitude Warning horn. We quickly accomplished the memory and QRH items; declared an emergency and began an emergency descent. On the descent and approach we received additional warnings such as 'Low Idle' and 'Speed Brake Do Not Deploy.'As soon as we could; the Captain called the flight attendants to advise them of our situation. Fortunately we were able to get to a lower altitude before the passenger masks deployed. We transferred control of the airplane and discussed making a PA. However; we were at 2000 feet; and decided to do it when we landed. Once landed; the First Officer made a PA explaining what had occurred. We landed overweight uneventfully and taxied to the gate. Finally; the Captain called Dispatch; SOD; Maintenance Control; and the Chief Pilot on call. During a conversation with Maintenance Control the Captain was advised that the most likely cause of our pressurization controller fault and other multiple failures was a faulty air/ground sensor.

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	1021091
Time
Date	201207
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	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Squat Switch
Person 1
Function	First Officer
Experience	Flight Crew Last 90 Days 102 Flight Crew Type 160
Person 2
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 247
Events
Anomaly	Aircraft Equipment Problem Critical