B777 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 172; Flight Crew Total 17678; Flight Crew Type 9646
Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance
General Flight Cancelled / Delayed
Human Factors; Procedure
Unable to complete Before Pushback checklist. Fuel Pumps checklist line would not close loop and show 'Green'. Right center tank boost pump pressure light remained 'on'. Attempted reset of switch including after temporarily removing all other high load electrical (fuel; hydraulic pumps). No load shed indicated on electrical synoptic. Unable get pump on. Electronic Checklist would not complete and interestingly; item and checklist override were not available. Contacted local maintenance and entered item in ACARS. Maintenance was unable to solve the problem before crew duty time expired. The next day we were told it was a 'load shed' as far as they could tell. I know that one or both center fuel pumps can shed before engine start on a single source electric (APU); any time; and the Electronic Checklist is not affected. I suspected some other problem and certainly wouldn't fly after bypassing any checklist items. Flight was cancelled.
During pre-pushback cockpit preparation; aircraft appeared to load shed electrically normally for fuel system center right fuel pump; but electronic before push checklist would not indicate it had. Worked with station maintenance to correct with no success. Flight eventually cancelled for malfunction. Following day; station maintenance advised that; following a maintenance turn of both engines; system load shedding of fuel pumps operated normally; including electronic checklist logic for pre-start. Suggestion was made that our crew had misinterpreted checklist on previous day. This is NOT true. Aircraft system logic had prevent us from completing the checklist; i.e.; fuel pumps line of before push checklist could not be checked Green as complete and normal.
B777 flight crew reported inability to complete the Before Pushback Checklist due to a persistent fuel pressure light illumination. Maintenance was unable to correct the problem by the time the crew timed-out and the flight was cancelled.