Narrative:

I was the captain and PF of flight. Shortly after leveling at FL330, first officer noticed that the cabin pressure altitude was above 9000 ft and the cabin rate of climb indicator was indicating a 400 FPM climb. We accomplished the 'unscheduled pressurization change' procedure in the QRH. After selecting standby, then manual pressurization controls, neither had any effect! The cabin rate of climb was still steady at 400 FPM rate of climb. The cabin was then at 10000 ft and the outflow valve was fully closed. We notified ATC of the problem and started an emergency descent eventually to 10000 ft when MEA permitted, while accomplishing the 'cabin altitude rapid descent' procedure. During the early part of the descent, the cabin altitude warning horn sounded, but later (10-15 seconds) silenced when the cabin altitude descended below 10000 ft. The masks did not deploy in the passenger cabin. (I think it was due to the short duration at 10000 ft.) during the descent, first officer attempted to contact dispatch via air carrier Y net and ACARS (aircraft position 10-40 mi southeast of rsk VOR), but was unable to do so until we were approximately 40 mi northwest of abq VOR. Abq was the closest airport considering point in time. So we accomplished diversion to abq. A short delay was required while waiting for the thunderstorm at abq to clear, and we were sequenced behind a second emergency aircraft (air carrier Z). However, an uneventful approach and landing on runway 3 was accomplished. Several passenger complained of ear problems which (I suspect) occurred during the initial part of the descent. After seeing the cabin altitude start descending, I maintained partial power in the descent. Using speed brake and airspeed approximately 320 KTS. Medical personnel met the aircraft to attend those passenger who needed assistance in abq.

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Original NASA ASRS Text

Title: B737-300 FLT CREW PERFORMS AN EMER DSCNT AFTER LOSS OF CABIN PRESSURE. DIVERTS TO AND LANDS AFTER A TSTM SPONSORED TFC DELAY AT ABQ.

Narrative: I WAS THE CAPT AND PF OF FLT. SHORTLY AFTER LEVELING AT FL330, FO NOTICED THAT THE CABIN PRESSURE ALT WAS ABOVE 9000 FT AND THE CABIN RATE OF CLB INDICATOR WAS INDICATING A 400 FPM CLB. WE ACCOMPLISHED THE 'UNSCHEDULED PRESSURIZATION CHANGE' PROC IN THE QRH. AFTER SELECTING STANDBY, THEN MANUAL PRESSURIZATION CTLS, NEITHER HAD ANY EFFECT! THE CABIN RATE OF CLB WAS STILL STEADY AT 400 FPM RATE OF CLB. THE CABIN WAS THEN AT 10000 FT AND THE OUTFLOW VALVE WAS FULLY CLOSED. WE NOTIFIED ATC OF THE PROB AND STARTED AN EMER DSCNT EVENTUALLY TO 10000 FT WHEN MEA PERMITTED, WHILE ACCOMPLISHING THE 'CABIN ALT RAPID DSCNT' PROC. DURING THE EARLY PART OF THE DSCNT, THE CABIN ALT WARNING HORN SOUNDED, BUT LATER (10-15 SECONDS) SILENCED WHEN THE CABIN ALT DSNDED BELOW 10000 FT. THE MASKS DID NOT DEPLOY IN THE PAX CABIN. (I THINK IT WAS DUE TO THE SHORT DURATION AT 10000 FT.) DURING THE DSCNT, FO ATTEMPTED TO CONTACT DISPATCH VIA ACR Y NET AND ACARS (ACFT POS 10-40 MI SE OF RSK VOR), BUT WAS UNABLE TO DO SO UNTIL WE WERE APPROX 40 MI NW OF ABQ VOR. ABQ WAS THE CLOSEST ARPT CONSIDERING POINT IN TIME. SO WE ACCOMPLISHED DIVERSION TO ABQ. A SHORT DELAY WAS REQUIRED WHILE WAITING FOR THE TSTM AT ABQ TO CLR, AND WE WERE SEQUENCED BEHIND A SECOND EMER ACFT (ACR Z). HOWEVER, AN UNEVENTFUL APCH AND LNDG ON RWY 3 WAS ACCOMPLISHED. SEVERAL PAX COMPLAINED OF EAR PROBS WHICH (I SUSPECT) OCCURRED DURING THE INITIAL PART OF THE DSCNT. AFTER SEEING THE CABIN ALT START DSNDING, I MAINTAINED PARTIAL PWR IN THE DSCNT. USING SPD BRAKE AND AIRSPD APPROX 320 KTS. MEDICAL PERSONNEL MET THE ACFT TO ATTEND THOSE PAX WHO NEEDED ASSISTANCE IN ABQ.

Data retrieved from NASA's ASRS site as of July 2007 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.