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An air carrier B737-200 crew made an emergency descent. They found out later that they had not turned on the pressurization system.
| Attributes | |
| ACN | 340932 |
| Time | |
| Date | 199606 |
| Day | Mon |
| Local Time Of Day | 0001 To 0600 |
| Place | |
| Locale Reference | airport : tul |
| State Reference | OK |
| Altitude | msl bound lower : 10000 msl bound upper : 26000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zkc |
| Operator | common carrier : air carrier |
| Make Model Name | B737-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : intermediate altitude ground : preflight other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : instrument pilot : atp pilot : commercial |
| Experience | flight time last 90 days : 225 flight time total : 8000 flight time type : 6600 |
| ASRS Report | 340932 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 240 flight time total : 6500 flight time type : 1250 |
| ASRS Report | 339975 |
| Events | |
| Anomaly | aircraft equipment problem : critical inflight encounter : weather non adherence : published procedure other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : declared emergency none taken : anomaly accepted other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Bleeds off takeoff out of tul and immediate turn to east off of runway 36R, to avoid thunderstorms. I was flying and continued to retune radar and make course adjustments for a better ride (deviations were approved by ATC). Turbulence was light to moderate, so I told the flight attendants to remain seated. Climbing through FL260 we got an 'autofail' light on our cabin pressurization system and switched to 'standby' mode. The cabin altitude continued to climb, so the first officer switched to manual and tried to close the outflow valve. Next we got the altitude warning horn for the cabin and the masks deployed. We accomplished an emergency descent with ATC concurrence and completed the flight at 10000 ft with no further incident. I later checked with maintenance concerning that aircraft and learned that the pressurization system checked out ok. I then discussed it with my first officer and we now believe we failed to reconfigure the pressurization system with engine bleeds 'on' and the APU bleed 'off' after our initial no bleeds takeoff. We immediately flew to meet with our chief pilot and submitted an irregularity report. Supplemental information from acn 339975: 11 1/2 hours into crew duty day. Returned from mci after holding for over 1 hour. Over 1 hour 15 mins on ground to resolve plan.
Original NASA ASRS Text
Title: AN ACR B737-200 CREW MADE AN EMER DSCNT. THEY FOUND OUT LATER THAT THEY HAD NOT TURNED ON THE PRESSURIZATION SYS.
Narrative: BLEEDS OFF TKOF OUT OF TUL AND IMMEDIATE TURN TO E OFF OF RWY 36R, TO AVOID TSTMS. I WAS FLYING AND CONTINUED TO RETUNE RADAR AND MAKE COURSE ADJUSTMENTS FOR A BETTER RIDE (DEVS WERE APPROVED BY ATC). TURB WAS LIGHT TO MODERATE, SO I TOLD THE FLT ATTENDANTS TO REMAIN SEATED. CLBING THROUGH FL260 WE GOT AN 'AUTOFAIL' LIGHT ON OUR CABIN PRESSURIZATION SYS AND SWITCHED TO 'STANDBY' MODE. THE CABIN ALT CONTINUED TO CLB, SO THE FO SWITCHED TO MANUAL AND TRIED TO CLOSE THE OUTFLOW VALVE. NEXT WE GOT THE ALT WARNING HORN FOR THE CABIN AND THE MASKS DEPLOYED. WE ACCOMPLISHED AN EMER DSCNT WITH ATC CONCURRENCE AND COMPLETED THE FLT AT 10000 FT WITH NO FURTHER INCIDENT. I LATER CHKED WITH MAINT CONCERNING THAT ACFT AND LEARNED THAT THE PRESSURIZATION SYS CHKED OUT OK. I THEN DISCUSSED IT WITH MY FO AND WE NOW BELIEVE WE FAILED TO RECONFIGURE THE PRESSURIZATION SYS WITH ENG BLEEDS 'ON' AND THE APU BLEED 'OFF' AFTER OUR INITIAL NO BLEEDS TKOF. WE IMMEDIATELY FLEW TO MEET WITH OUR CHIEF PLT AND SUBMITTED AN IRREGULARITY RPT. SUPPLEMENTAL INFO FROM ACN 339975: 11 1/2 HRS INTO CREW DUTY DAY. RETURNED FROM MCI AFTER HOLDING FOR OVER 1 HR. OVER 1 HR 15 MINS ON GND TO RESOLVE PLAN.
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.