.
all entered data is retained by the FMC, and when power is restored the
RTE LEGS page is displayed with the scratchpad message
SELECT ACTIVE WPT/LEG.
Before LNAV can engage, the FMC must be instructed how to return to the route. Select the desired active waypoint and proceed direct or intercept a course to the waypoint.
FMC Failure YA686, YA687, YC153 - YK104
Single FMC Failure
The FMC/CDU is designed to automatically preserve the most capable modes of navigation and guidance that can be maintained with the equipment and navigation aids available. If an error or system failure results in reduced capability, then the FMC may generate a crew message for display in the CDU scratchpad. If other system inputs to the FMC should fail, affected CDU displays are blanked to prevent the display of misleading or erroneous data. For example, loss of the total fuel input causes some performance related data to be blank. The messages and FMC internal responses provide an orderly transition from full FMC guided flight to less automated capability.
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Flight Management, Navigation -Flight Management Computer 737 Flight Crew Operations Manual
If the right FMC fails, the FMC alert light and the FMC message light will illuminate. The message SINGLE FMC OPERATION will be displayed in both scratchpads. VTK will display on the right navigation display. LNAV and VNAV will disengage if autopilot B is in use (can be reengaged if autopilot A is selected). After 25 to 30 seconds, the right navigation display will display failure information. The right navigation display may be restored by placing the FMC source select switch to BOTH ON L.
Note: If the above indications are observed with no VTK on the right navigation display, there is a disagreement between left and right FMC data. Moving the FMC Source Select Switch to BOTH ON L should allow the two FMCs to resynchronize. The switch may then be returned to NORMAL when the message DUAL FMC OP RESTORED is displayed on both scratch pads.
If the left FMC fails, the FMC alert light will illuminate. The MENU page will appear on both CDUs. VTK will appear on the left navigation display. LNAV and VNAV will disengage, but can be reengaged if autopilot B is in use or is selected. After 25 to 30 seconds, the left navigation display will display failure information. To restore full operation, the FMC source select switch must be moved to BOTH ON R.
Note: During an FMC software restart, the navigation display map track may rapidly slew to 0 degrees then to the correct value.
Dual FMC Failure
If both FMCs fail, the FMC alert light will illuminate. The MENU page will appear on both CDUs. VTK will appear on both navigation displays. LNAV and VNAV will disengage. After 25 to 30 seconds, both navigation displays will display failure information.
FMC Failure YA613, YA626, YA721 - YA809
YA613, YA626 If the FMC fails, the FMC alert light will illuminate. The FMC/CDU FAIL light will appear on both CDUs, and both CDUs will display failure modes. VTK will appear on both navigation displays. LNAV and VNAV will disengage. After 25 to 30 seconds, both navigation displays will display failure information.
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11.32.6 June 1, 2003
Flight Management, Navigation -Flight Management Computer 737 Flight Crew Operations Manual
YA721 - YA809 If the FMC fails, the FMC alert light will illuminate. The MENU page will appear on both CDUs. VTK will appear on both navigation displays. LNAV and VNAV will disengage. After 25 to 30 seconds, both navigation displays will display failure information.
Note: During an FMC software restart, the navigation display map track may rapidly slew to 0 degrees then to the correct value.
Copyright . The Boeing Company. See title page for details.
Flight Management, Navigation -Flight Management Computer 737 Flight Crew Operations Manual
Intentionally
Blank
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11.32.8 June 1, 2003
This Section Applies to YA613, YA626, YA801 - YA809, YC411 - YD655
Company Data Link
The airplane communications system enables two–way data link communications between the FMC and airline operations. A downlink occurs when data is transferred from the FMC and transmitted through the airplane communications system to a receiver on the ground. Data may be downlinked from the FMC either manually or automatically. An uplink is the opposite of a downlink; data is transmitted from a ground station for input to the FMC. Data may be uplinked at the discretion of the airline operations dispatcher or in response to a downlink request.
Copyright . The Boeing Company. See title page for details. 中國航空網 m.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：737NG機組操作手冊Flight Crew Operations Manual FCOM 3(86)
