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International dispatcher's computer system malfunctions. Will not provide flight plan with optimum step climbs.
| Attributes | |
| ACN | 597687 |
| Time | |
| Date | 200310 |
| Day | Thu |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : vhhh.airport |
| State Reference | FO |
| Altitude | agl single value : 0 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B747-400 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : parked |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | other personnel |
| Qualification | other |
| ASRS Report | 597687 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | non adherence : company policies |
| Independent Detector | other other : person 1 |
| Resolutory Action | flight crew : overcame equipment problem |
| Consequence | other |
| Supplementary | |
| Problem Areas | Company |
| Primary Problem | Company |
Narrative:
During flight planning the computer kept giving an error saying unable to carry payload due to driftdown/decompression. Further investigation showed the flight was climbing far too soon to FL330 and then not climbing any further. It was also discovered that by planning the flight over elato rather than envar the problem disappeared and the flight climbed normally to FL290 then FL330 then FL350 and finally FL370 and carried all the load. Going back to envar cost me payload and any attempts to get the flight to climb resulted in the driftdown error again. I finally ended up working with dispatch and hand selecting climb points and altitudes. Since there is no way to do this automatically, we ended up searching through many combinations before finding an optimal. We never were able to carry the payload we should have. I spoke to the captain before departure and explained the problem. He set up the climbs on the cockpit computer and step climbed to FL370 and got the burn we should have gotten. We ended up leaving payload on the ground due to this problem. This also required a considerable expenditure of man-hours just to get a usable, but far from optimal flight plan.
Original NASA ASRS Text
Title: INTL DISPATCHER'S COMPUTER SYS MALFUNCTIONS. WILL NOT PROVIDE FLT PLAN WITH OPTIMUM STEP CLBS.
Narrative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
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.