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Captain reported conflict in new aircraft performance manuals.
| Attributes | |
| ACN | 1762544 |
| Time | |
| Date | 202009 |
| Aircraft 1 | |
| Make Model Name | B737-800 |
| Flight Phase | Other Non-Flight |
| Component | |
| Aircraft Component | Other Documentation |
| Person 1 | |
| Function | Pilot Flying Captain |
| Qualification | Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine |
| Events | |
| Anomaly | Deviation - Procedural Published Material / Policy |
Narrative:
A recent change to the B-737 performance manual authorizes standard (standard) thrust takeoffs with a tailwind 'provided the data in the thrust/V speed section of the tps (takeoff performance system) are based on a tailwind equal to or greater than the actual wind'. This exception is correctly explained on the takeoff card under 'unplanned tailwind takeoff'. However; the spar matrix; (another quick reference tool in the performance manual) incorrectly shows that standard thrust takeoffs are permitted with a tailwind. The only exception listed in the spar matrix for the standard thrust/tailwind combination is ball note 1 which states 'check the list of conditions in --use of standard thrust for takeoff is not authorized--'. This list used to include tailwind; but in accordance with the new tps tailwind procedures referenced above it was removed with the last revision. Add the already present ball note 4 (provided the data in the thrust/V speed section of the tps are based on a tailwind equal to or greater than the actual wind) on the spar matrix to the standard thrust/tailwind combination.
Original NASA ASRS Text
Title: Captain reported conflict in new aircraft performance manuals.
Narrative: A recent change to the B-737 Performance Manual authorizes standard (STD) thrust takeoffs with a tailwind 'provided the data in the Thrust/V speed section of the TPS (Takeoff Performance System) are based on a tailwind equal to or greater than the actual wind'. This exception is correctly explained on the takeoff card under 'Unplanned Tailwind Takeoff'. However; the SPAR matrix; (another quick reference tool in the Performance Manual) incorrectly shows that STD thrust takeoffs are permitted with a tailwind. The only exception listed in the Spar matrix for the STD thrust/tailwind combination is ball note 1 which states 'Check the list of conditions in --Use of STD thrust for takeoff is not authorized--'. This list used to include tailwind; but in accordance with the new TPS tailwind procedures referenced above it was removed with the last revision. Add the already present ball note 4 (provided the data in the Thrust/V speed section of the TPS are based on a tailwind equal to or greater than the actual wind) on the SPAR matrix to the STD thrust/tailwind combination.
Data retrieved from NASA's ASRS site 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.