Narrative:

While accomplishing a landing gear job card during b-check; found paragraph B(1)(e) and (f) would not work. This indicated that ldg extd/retr 1 (landing gear extend/retract) is not being powered. This is to both medium large transport (main landing gear) sel/bypass valve and nlg sel/bypass valve system-1 solenoid; reference wdm (wiring diagram manual) 32-31-11. System-2 worked alright in accordance with (in accordance with) landing gear job card. Further troubleshooting found that there were two problems with the system-1 part of the medium large transport extd/retr. The first one was that the up-1 power/DN1 (power/down); power/DN1 ground (ground) switch was faulted in the lgclm (landing gear control lever module) M32057. The second fault was found at the P105; intergration panel TB3001 (terminal block); [where] two contacts were pulled out. Both of these faults were corrected in accordance with wdm/amm and the landing gear job card accomplished again. All checked good. The problem seems to be that this is the only way to check both systems. If the other system would have failed; the medium large transport would fail to retract/extend when selected. The [job] card appears to be not assigned at every b-check. The interval should be every b-check or sooner. The problem has no prior notice of fault.

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Original NASA ASRS Text

Title: A Line Lead Technician reports that during accomplishment of a landing gear check job card; the system-1 solenoid for the Landing Gear Extend/Retract-1 was found not being powered. No messages or indication of faults on the B777's EICAS displays. If power to the 'alternate' system 2 solenoid had also failed; the B777 landing gears would not extend or retract when selected.

Narrative: While accomplishing a Landing Gear Job Card during B-Check; found paragraph B(1)(e) and (f) would not work. This indicated that LDG EXTD/RETR 1 (Landing Gear Extend/Retract) is not being powered. This is to both MLG (Main Landing Gear) SEL/BYPASS VALVE and NLG SEL/BYPASS VALVE System-1 Solenoid; reference WDM (Wiring Diagram Manual) 32-31-11. System-2 worked alright IAW (in accordance with) Landing Gear Job Card. Further troubleshooting found that there were two problems with the System-1 part of the MLG EXTD/RETR. The first one was that the UP-1 PWR/DN1 (Power/Down); PWR/DN1 GND (Ground) switch was faulted in the LGCLM (Landing Gear Control Lever Module) M32057. The second fault was found at the P105; Intergration Panel TB3001 (Terminal Block); [where] two contacts were pulled out. Both of these faults were corrected IAW WDM/AMM and the Landing Gear Job Card accomplished again. All checked good. The problem seems to be that this is the only way to check both systems. If the other system would have failed; the MLG would fail to retract/extend when selected. The [Job] card appears to be not assigned at every B-Check. The interval should be every B-Check or sooner. The problem has no prior notice of fault.

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.