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|
Attributes | |
ACN | 948135 |
Time | |
Date | 201105 |
Local Time Of Day | 0601-1200 |
Place | |
Locale Reference | ZZZ.Airport |
State Reference | US |
Aircraft 1 | |
Make Model Name | B737-800 |
Operating Under FAR Part | Part 121 |
Flight Phase | Taxi |
Flight Plan | IFR |
Component | |
Aircraft Component | Pressurization System |
Person 1 | |
Function | Pilot Flying First Officer |
Events | |
Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy |
Narrative:
During CDU preflight noted that the takeoff performance report (tpr) listed both runway xxl and yyl; which were the departure runways listed in the ATIS; also noted that data for yyl required a no engine bleed takeoff. [We] briefly consulted the flight handbook to refresh memory on switch positions and procedures. When conducting the departure briefing; discussed takeoff runways and taxi routes with captain. Also discussed need for no engine bleed takeoff if assigned yyl; at that time; both of us fully expected to be assigned xxl; which was entered in the FMC as the departure runway.after pushback; we elected to complete our before taxi flows and checklist prior to contacting ground metering so we could concentrate on ATC instructions and decrease our workload during taxi. Ground control then issued us taxi instructions for runway yyl. I entered the new runway in the FMC during taxi; re-briefed the performance data; and confirmed with the captain the need for a no engine bleed takeoff. At this point I configured the bleed/pack switches in accordance with the flight handbook and all of the switch positions were confirmed by the captain. During the takeoff run on yyl we received a master caution light. Captain (pilot not flying) verbalized the 'auto fail' caution light; reset the master caution; and elected to continue the takeoff. Engine bleeds were re-established according to the flight handbook by the pilot not flying; but it became apparent that we had limited control of the cabin altitude. The pilot not flying advised ATC of the problem and received clearance to maintain 5;000 MSL to run the checklist. After running the 'auto fail' check list from the QRH; it became apparent that we could only partially control the pressurization in manual mode as the auto and alternate modes were not available. After consulting with dispatch and maintenance control; we returned to ZZZ. After we blocked in; we reviewed our performance and procedures to see if we had missed anything during this event. After retracing our steps several times; we discovered that during our original taxi checklist; we had shut the APU down; which is normal for the 'bleeds on' takeoff we originally anticipated for runway xxl. When given a different runway (yyl); although we configured the bleed/pack switches for a no engine bleeds takeoff as briefed; we neglected to restart the APU and inadvertently accomplished the takeoff unpressurized.
Original NASA ASRS Text
Title: A B737-800 flight crew was unable to control pressurization following a no bleed air takeoff and returned to their departure airport.
Narrative: During CDU preflight noted that the Takeoff Performance Report (TPR) listed both Runway XXL and YYL; which were the departure runways listed in the ATIS; also noted that data for YYL required a no engine bleed takeoff. [We] briefly consulted the Flight Handbook to refresh memory on switch positions and procedures. When conducting the departure briefing; discussed takeoff runways and taxi routes with Captain. Also discussed need for no engine bleed takeoff if assigned YYL; at that time; both of us fully expected to be assigned XXL; which was entered in the FMC as the departure runway.After pushback; we elected to complete our before taxi flows and checklist prior to contacting ground metering so we could concentrate on ATC instructions and decrease our workload during taxi. Ground Control then issued us taxi instructions for Runway YYL. I entered the new runway in the FMC during taxi; re-briefed the performance data; and confirmed with the Captain the need for a no engine bleed takeoff. At this point I configured the bleed/pack switches in accordance with the Flight Handbook and all of the switch positions were confirmed by the Captain. During the takeoff run on YYL we received a Master Caution light. Captain (pilot not flying) verbalized the 'Auto Fail' caution light; reset the master caution; and elected to continue the takeoff. Engine bleeds were re-established according to the Flight Handbook by the pilot not flying; but it became apparent that we had limited control of the cabin altitude. The pilot not flying advised ATC of the problem and received clearance to maintain 5;000 MSL to run the checklist. After running the 'Auto Fail' check list from the QRH; it became apparent that we could only partially control the pressurization in manual mode as the Auto and Alternate modes were not available. After consulting with dispatch and maintenance control; we returned to ZZZ. After we blocked in; we reviewed our performance and procedures to see if we had missed anything during this event. After retracing our steps several times; we discovered that during our original taxi checklist; we had shut the APU down; which is normal for the 'bleeds on' takeoff we originally anticipated for Runway XXL. When given a different Runway (YYL); although we configured the bleed/pack switches for a no engine bleeds takeoff as briefed; we neglected to restart the APU and inadvertently accomplished the takeoff unpressurized.
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.