Narrative:

No pressurization after takeoff, masks dropped. Originated flight with on-time push. All was normal while reaching 10000 ft on departure. First officer was flying. We just completed clean-up after takeoff, I reached to place landing gear handle to 'off' position and at same time got a warning horn. Initially, my mind was associating gear handle to horn -- why? I directed first officer to level off, but he apparently did not hear me. Several other calls from ATC were received. I requested we level at 10000 and advised them we had a pressurization problem. Meanwhile, the first officer noticed the cabin rate of climb was high and cabin altitude was 9000 ft and climbing. He donned his oxygen mask, but did not level off or descend, but rather aircraft climbed to 14000 ft when he noticed the passenger oxygen mask light was on. Then he started a descent. Obviously, the cockpit noise level was quite high. I was coordinating with ATC and once I realized masks were deployed, I requested immediate return to abq. No emergency was declared. I then talked to flight attendant and told them problem. We were returning and there was no need to wear masks. I then made a PA to passenger, told them we had a pressurization problem and were returning to abq. Normal landing was made and taxi to gate. Operations had emt standing by at my request in case any passenger had physiological problems. Only 1 complained of ear hurting. On descent for landing first officer noticed the pressure controller switch was in the 'manual' position instead of 'automatic.' I notified dispatch, maintenance and chief pilot once on ground. Operations gave us spare aircraft and we continued trip. In retrospect, I should have taken control of aircraft immediately and leveled at 10000 ft while first officer did troubleshooting. In air traffic area, cockpit work level was high with added noise of horn and radios adding to confusion. The cause: appeared to be the first officer being interrupted during his preflight flow and not moving the switch back to 'automatic.' unfortunately, the before originating checklist (challenge/response) does not address that switch either. In the future my 10000 ft check will include the cabin altitude in the correct control switch position. This was a preventable incident.

Related reports:

Google
 

Original NASA ASRS Text

Title: B737-700 CREW HAD THE OXYGEN MASKS DROP BECAUSE OF MISSET PRESSURIZATION OUTFLOW VALVE CTL.

Narrative: NO PRESSURIZATION AFTER TKOF, MASKS DROPPED. ORIGINATED FLT WITH ON-TIME PUSH. ALL WAS NORMAL WHILE REACHING 10000 FT ON DEP. FO WAS FLYING. WE JUST COMPLETED CLEAN-UP AFTER TKOF, I REACHED TO PLACE LNDG GEAR HANDLE TO 'OFF' POS AND AT SAME TIME GOT A WARNING HORN. INITIALLY, MY MIND WAS ASSOCIATING GEAR HANDLE TO HORN -- WHY? I DIRECTED FO TO LEVEL OFF, BUT HE APPARENTLY DID NOT HEAR ME. SEVERAL OTHER CALLS FROM ATC WERE RECEIVED. I REQUESTED WE LEVEL AT 10000 AND ADVISED THEM WE HAD A PRESSURIZATION PROB. MEANWHILE, THE FO NOTICED THE CABIN RATE OF CLB WAS HIGH AND CABIN ALT WAS 9000 FT AND CLBING. HE DONNED HIS OXYGEN MASK, BUT DID NOT LEVEL OFF OR DSND, BUT RATHER ACFT CLBED TO 14000 FT WHEN HE NOTICED THE PAX OXYGEN MASK LIGHT WAS ON. THEN HE STARTED A DSCNT. OBVIOUSLY, THE COCKPIT NOISE LEVEL WAS QUITE HIGH. I WAS COORDINATING WITH ATC AND ONCE I REALIZED MASKS WERE DEPLOYED, I REQUESTED IMMEDIATE RETURN TO ABQ. NO EMER WAS DECLARED. I THEN TALKED TO FLT ATTENDANT AND TOLD THEM PROB. WE WERE RETURNING AND THERE WAS NO NEED TO WEAR MASKS. I THEN MADE A PA TO PAX, TOLD THEM WE HAD A PRESSURIZATION PROB AND WERE RETURNING TO ABQ. NORMAL LNDG WAS MADE AND TAXI TO GATE. OPS HAD EMT STANDING BY AT MY REQUEST IN CASE ANY PAX HAD PHYSIOLOGICAL PROBS. ONLY 1 COMPLAINED OF EAR HURTING. ON DSCNT FOR LNDG FO NOTICED THE PRESSURE CTLR SWITCH WAS IN THE 'MANUAL' POS INSTEAD OF 'AUTO.' I NOTIFIED DISPATCH, MAINT AND CHIEF PLT ONCE ON GND. OPS GAVE US SPARE ACFT AND WE CONTINUED TRIP. IN RETROSPECT, I SHOULD HAVE TAKEN CTL OF ACFT IMMEDIATELY AND LEVELED AT 10000 FT WHILE FO DID TROUBLESHOOTING. IN ATA, COCKPIT WORK LEVEL WAS HIGH WITH ADDED NOISE OF HORN AND RADIOS ADDING TO CONFUSION. THE CAUSE: APPEARED TO BE THE FO BEING INTERRUPTED DURING HIS PREFLT FLOW AND NOT MOVING THE SWITCH BACK TO 'AUTO.' UNFORTUNATELY, THE BEFORE ORIGINATING CHKLIST (CHALLENGE/RESPONSE) DOES NOT ADDRESS THAT SWITCH EITHER. IN THE FUTURE MY 10000 FT CHK WILL INCLUDE THE CABIN ALT IN THE CORRECT CTL SWITCH POS. THIS WAS A PREVENTABLE INCIDENT.

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.