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A B777 captain describes electrical load management system (elms) faults that appeared in cruise with the loss of the right main AC bus and right transfer bus. The existence of a boeing maintenance document released years earlier describing the exact same condition and recommended action was not known by their maintenance control; and was definitely not in their flight manual.
| Attributes | |
| ACN | 841846 |
| Time | |
| Date | 200907 |
| Local Time Of Day | 1801-2400 |
| Place | |
| Locale Reference | ZZZZ.ARTCC |
| State Reference | FO |
| Environment | |
| Flight Conditions | IMC |
| Aircraft 1 | |
| Make Model Name | B777-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Route In Use | Oceanic |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Electrical Power |
| Person 1 | |
| Function | Captain Pilot Flying |
| Experience | Flight Crew Last 90 Days 240 Flight Crew Total 30000 Flight Crew Type 5000 |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical Inflight Event / Encounter Fuel Issue |
Narrative:
Status showed a loss of some electrical load management system (elm)'s busses. We were left with a left-AC bus and left-transfer (xfer) bus only. We were unable to access the remaining four generators including the APU. Maintenance was unable to help and agreed that according the flight manual and boeing data; this configuration is not possible in the B-777. Completed the trip.second issue - APU ran for 7 hrs. After landing the fuel gauges and the FMC engine fuel burn record showed the engine burned the exact amount. There was no imbalance in the main fuel tanks; and the fuel calculations showed the APU burned no fuel in 7 hours. Talked with a line maintenance supervisor and he agreed everything that happened was not possible; and the fuel burn record had to be inaccurate; as this was not possible either.
Original NASA ASRS Text
Title: A B777 Captain describes electrical load management system (ELMS) faults that appeared in cruise with the loss of the right main AC bus and right transfer bus. The existence of a Boeing maintenance document released years earlier describing the exact same condition and recommended action was not known by their Maintenance Control; and was definitely not in their flight manual.
Narrative: Status showed a loss of some electrical load management system (ELM)'s busses. We were left with a LEFT-AC Bus and LEFT-Transfer (Xfer) Bus only. We were unable to access the remaining four generators including the APU. Maintenance was unable to help and agreed that according the flight manual and Boeing data; this configuration is not possible in the B-777. Completed the trip.Second issue - APU ran for 7 hrs. After landing the fuel gauges and the FMC engine fuel burn record showed the engine burned the exact amount. There was no imbalance in the main fuel tanks; and the fuel calculations showed the APU burned no fuel in 7 hours. Talked with a Line Maintenance Supervisor and he agreed everything that happened was not possible; and the fuel burn record had to be inaccurate; as this was not possible either.
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.