Narrative:

We departed sna configured for a bleeds off takeoff. At 800 ft MSL the first officer reduced the power, set V2 +20 KTS, selected N1 inadvertently instead of level change and turned the right flight director on. When I realized I was not getting pitch steering I called for level change. That is when I realized N1 was selected. The first officer selected level change and I disconnected the thrust levers and reduced the power to circuit breaker power. We continued the departure profile. Once we were cleaned up the after takeoff checklist was called for and the flow was completed by the first officer. I did not realize at the time that the takeoff checklist hadn't been completed and this may have been a result of the workload in the cockpit at the time and the confusion that was caused by the power setting. The consequence of not completing the checklist was that the bleeds did not get reestablished. Sometime after passing 10000 ft MSL and before reaching FL180 I turned off the APU. This set the stage for the next event. Passing approximately FL250 the cabin altitude warning horn sounded. That is when we realized the engine bleeds were off. We selected the bleeds on and ask for a descent. As we approached FL240 it was obvious that the cabin was under control and approaching back to 10000 ft MSL so we leveled at FL240. During the descent back to FL240 I called back to the flight attendants to ask if the masks had dropped and found that they had not. I told them that we'd had a pressurization problem and asked if everything was fine with them and the passenger. They said that they had not been aware of anything taking place and that the passenger were fine. We remained at FL240 until the cabin altitude was on schedule for our planned cruise altitude (FL350) approximately 7200 ft MSL then continued our climb en route with no further problems. Lessons learned: distractions from normal habit patterns can have unwanted results. When flying with new pilots the captain needs to be more vigilant about the first officer's duties. It is easy to get complacent when you are used to flying with more experienced pilots. Departing sna in a bleeds off confign it is imperative to brief where and when the bleeds need to be reestablished. Supplemental information from acn 582333: lessons learned: this was my first flight from sna in a B737-400 and my 3RD or 4TH total. We had just departed earlier that day in a B737-700 without event. Though captain briefed the departure well and I had read the 10-7 pages twice (though they don't make much reference to bleeds), I clearly was not as well prepared for the departure as I should have been. In the future I will spend considerably more time reviewing and 'chair-flying' the noise abatement profile for the appropriate aircraft, with special emphasis on reestablishing bleeds in the B737-400. Distraction can lead to further problems. Once we repaired the initial error, I should have diligently stuck to the normal procedures, as completing the after takeoff checklist would have prevented the later problem. Discussion and analysis could easily have waited until we reached cruise altitude.

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Original NASA ASRS Text

Title: FLT CREW OF B734 FAILED TO TURN PRESSURIZATION BLEEDS BACK ON AFTER BLEEDS OFF NOISE ABATEMENT TKOF AT SNA. EXPERIENCED CABIN ALT WARNING HORN DUE TO EXCESSIVE CABIN ALT AFTER APU SHUT DOWN.

Narrative: WE DEPARTED SNA CONFIGURED FOR A BLEEDS OFF TKOF. AT 800 FT MSL THE FO REDUCED THE PWR, SET V2 +20 KTS, SELECTED N1 INADVERTENTLY INSTEAD OF LEVEL CHANGE AND TURNED THE R FLT DIRECTOR ON. WHEN I REALIZED I WAS NOT GETTING PITCH STEERING I CALLED FOR LEVEL CHANGE. THAT IS WHEN I REALIZED N1 WAS SELECTED. THE FO SELECTED LEVEL CHANGE AND I DISCONNECTED THE THRUST LEVERS AND REDUCED THE PWR TO CB PWR. WE CONTINUED THE DEP PROFILE. ONCE WE WERE CLEANED UP THE AFTER TKOF CHKLIST WAS CALLED FOR AND THE FLOW WAS COMPLETED BY THE FO. I DID NOT REALIZE AT THE TIME THAT THE TKOF CHKLIST HADN'T BEEN COMPLETED AND THIS MAY HAVE BEEN A RESULT OF THE WORKLOAD IN THE COCKPIT AT THE TIME AND THE CONFUSION THAT WAS CAUSED BY THE PWR SETTING. THE CONSEQUENCE OF NOT COMPLETING THE CHKLIST WAS THAT THE BLEEDS DID NOT GET REESTABLISHED. SOMETIME AFTER PASSING 10000 FT MSL AND BEFORE REACHING FL180 I TURNED OFF THE APU. THIS SET THE STAGE FOR THE NEXT EVENT. PASSING APPROX FL250 THE CABIN ALT WARNING HORN SOUNDED. THAT IS WHEN WE REALIZED THE ENG BLEEDS WERE OFF. WE SELECTED THE BLEEDS ON AND ASK FOR A DSCNT. AS WE APCHED FL240 IT WAS OBVIOUS THAT THE CABIN WAS UNDER CTL AND APCHING BACK TO 10000 FT MSL SO WE LEVELED AT FL240. DURING THE DSCNT BACK TO FL240 I CALLED BACK TO THE FLT ATTENDANTS TO ASK IF THE MASKS HAD DROPPED AND FOUND THAT THEY HAD NOT. I TOLD THEM THAT WE'D HAD A PRESSURIZATION PROB AND ASKED IF EVERYTHING WAS FINE WITH THEM AND THE PAX. THEY SAID THAT THEY HAD NOT BEEN AWARE OF ANYTHING TAKING PLACE AND THAT THE PAX WERE FINE. WE REMAINED AT FL240 UNTIL THE CABIN ALT WAS ON SCHEDULE FOR OUR PLANNED CRUISE ALT (FL350) APPROX 7200 FT MSL THEN CONTINUED OUR CLB ENRTE WITH NO FURTHER PROBS. LESSONS LEARNED: DISTRACTIONS FROM NORMAL HABIT PATTERNS CAN HAVE UNWANTED RESULTS. WHEN FLYING WITH NEW PLTS THE CAPT NEEDS TO BE MORE VIGILANT ABOUT THE FO'S DUTIES. IT IS EASY TO GET COMPLACENT WHEN YOU ARE USED TO FLYING WITH MORE EXPERIENCED PLTS. DEPARTING SNA IN A BLEEDS OFF CONFIGN IT IS IMPERATIVE TO BRIEF WHERE AND WHEN THE BLEEDS NEED TO BE REESTABLISHED. SUPPLEMENTAL INFO FROM ACN 582333: LESSONS LEARNED: THIS WAS MY FIRST FLT FROM SNA IN A B737-400 AND MY 3RD OR 4TH TOTAL. WE HAD JUST DEPARTED EARLIER THAT DAY IN A B737-700 WITHOUT EVENT. THOUGH CAPT BRIEFED THE DEP WELL AND I HAD READ THE 10-7 PAGES TWICE (THOUGH THEY DON'T MAKE MUCH REF TO BLEEDS), I CLRLY WAS NOT AS WELL PREPARED FOR THE DEP AS I SHOULD HAVE BEEN. IN THE FUTURE I WILL SPEND CONSIDERABLY MORE TIME REVIEWING AND 'CHAIR-FLYING' THE NOISE ABATEMENT PROFILE FOR THE APPROPRIATE ACFT, WITH SPECIAL EMPHASIS ON REESTABLISHING BLEEDS IN THE B737-400. DISTR CAN LEAD TO FURTHER PROBS. ONCE WE REPAIRED THE INITIAL ERROR, I SHOULD HAVE DILIGENTLY STUCK TO THE NORMAL PROCS, AS COMPLETING THE AFTER TKOF CHKLIST WOULD HAVE PREVENTED THE LATER PROB. DISCUSSION AND ANALYSIS COULD EASILY HAVE WAITED UNTIL WE REACHED CRUISE ALT.

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.