Dispatched with the auto pressurization controller deferred; the flight crew of a B737-300 was unabl...

Narrative:

Maintenance at our departure station put the pressurization auto mode controller on MEL. We departed and climbed to FL330; operating the pressurization in the standby mode. Shortly after level off I looked at the cabin rate indicator and it was indicating a climb of 100fpm. The actual cabin was reading about 7500'; about 1000 feet above normal for this altitude. I continued to monitor the gauge and saw the cabin was now at 8500'. I referenced the QRH and set the pressure mode to manual and tried to close the outflow value. The indicator showed full closed. The cabin was still climbing 100fpm and was now at 9000'. We put on our oxygen masks and I called ATC for an immediate descent to 10;000'. Emergency was declared and the the first officer initiated the descent. I called the flight attendants and passengers to take their seats. As the first officer pulled the power back the cabin started to climb at 500fpm but shortly settled down. Passing FL230 the cabin started to descend at 1500fpm. We now had the pressurization under control again. I asked ATC for a level off at FL220; switched the pressurization mode back to standby and the cabin was under control. I brought the cabin back down to 3000 ft. We removed our masks and asked ATC to terminate the emergency. We continued to our destination and had a safe landing. The cabin never reached 10;000' and the horn never activated. The first officer did an outstanding job flying and descending the aircraft in a smooth and coordinated manor. One thing all of us who were glasses might keep in mind. When I removed my mask I hit my glasses and one of my lenses fell out. I had difficulty reading and looking at the gauges with one eye. My spare glasses were in my suit case and difficult to retrieve. I found my missing lens about five minutes later in the garbage bag next to the first officer's seat. I now keep my spare glass in my hand bag next to my seat.

Original NASA ASRS Text

Title: Dispatched with the auto pressurization controller deferred; the Flight Crew of a B737-300 was unable to maintain the appropriate cabin altitude with the standby system. Declared an emergency and descended to an altitude where manual control of the outflow valve was achieved.

Narrative: Maintenance at our departure station put the pressurization auto mode controller on MEL. We departed and climbed to FL330; operating the pressurization in the standby mode. Shortly after level off I looked at the cabin rate indicator and it was indicating a climb of 100fpm. The actual cabin was reading about 7500'; about 1000 feet above normal for this altitude. I continued to monitor the gauge and saw the cabin was now at 8500'. I referenced the QRH and set the pressure mode to manual and tried to close the outflow value. The indicator showed full closed. The cabin was still climbing 100fpm and was now at 9000'. We put on our oxygen masks and I called ATC for an immediate descent to 10;000'. Emergency was declared and the the First Officer initiated the descent. I called the flight attendants and passengers to take their seats. As the First Officer pulled the power back the cabin started to climb at 500fpm but shortly settled down. Passing FL230 the cabin started to descend at 1500fpm. We now had the pressurization under control again. I asked ATC for a level off at FL220; switched the pressurization mode back to standby and the cabin was under control. I brought the cabin back down to 3000 ft. We removed our masks and asked ATC to terminate the emergency. We continued to our destination and had a safe landing. The cabin never reached 10;000' and the horn never activated. The first officer did an outstanding job flying and descending the aircraft in a smooth and coordinated manor. One thing all of us who were glasses might keep in mind. When I removed my mask I hit my glasses and one of my lenses fell out. I had difficulty reading and looking at the gauges with one eye. My spare glasses were in my suit case and difficult to retrieve. I found my missing lens about five minutes later in the garbage bag next to the First Officer's seat. I now keep my spare glass in my hand bag next to my seat.

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	932080
Time
Date	201102
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
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	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

Dispatched with the auto pressurization controller deferred; the flight crew of a B737-300 was unable to maintain the appropriate cabin altitude with the standby system. Declared an emergency and descended to an altitude where manual control of the outflow valve was achieved.