(b)
The TRUE/NORM switch controls the selection of the north reference. Selecting NORM results in a magnetic north referenced display, so long as valid magnetic heading data is available. The display automatically switches to a true north reference when magnetic data is unavailable. Selecting TRUE results is a true north referenced display regardless of the availability of magnetic heading.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
31-61-00
ALL ú ú 36 Page 88V ú Feb 18/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
(c)
The EIU SEL (selector) switch controls the selection of the EIU which provides data to EICAS. In the AUTO position, the left EIU drives the EICAS displays. If the left EIU fails, the EICAS automatically sequences to the center and then to the right EIU. The left, center or right switch position cause the respective EIU to be hard-selected as a source for the EICAS. Failure of the selected EIU will cause the EICAS displays to blank until a functional EIU is selected.
(d)
The EIU selector switch interfaces directly to the DU's as open/ground discretes. The DU's decode the switch positions and use the data to select the appropriate EIU input bus.
(e)
The EVENT RCD switch causes maintenance data to be recorded in the EICAS non-volatile memory.
(f)
Separate upper and lower DU manual brightness controls are provided to vary the intensity of the main and auxiliary displays.
(4) Source Selector Switches
(a)
The EFIS sensor and EIU data source selection is controlled by the source select switches located at the extreme left and right ends of the CAPT'S and F/O'S instrument panels.
(b)
The CAPT'S EIU source select switch functions identically to the EICAS EIU selector switch described in the previous section. The F/O'S EIU source select switch functions similarly, except that selecting the AUTO position results in a sequence of right, center, left instead of left, center, right.
(c)
The remaining source select switches control data source selection for the FLT DIR (flight director), NAV (navigation data), IRS (inertial reference system) and the ADC (air data computer).
(d)
These switches interface to the EIUs as open/ground discretes. If the selected source fails, the affected parameters are not available until an alternate data source has been selected.
(e)
All of the same sources are available to the CAPT and F/O, with the exception that the left CDU can only be selected by the CAPT and the right CDU can only be selected by the F/O.
(f)
An EICAS message is generated if both the CAPT and F/O select the same EFIS data source. No message will be generated if the same FCCs are selected for the flight director.
B. EFIS Operation and Control
(1)
General
(a) The following describes the operation of the flight crew controls and associated EFIS display formats.
(2)
EFIS Mode Controls
(a) General
1) Control of the various EFIS display formats and pilot selectable features is implemented through the CAPT'S and F/O'S EFIS Control Panels (EFIS CPs).
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址:747-400 AMM 飞机维护手册 指示/记录系统 2(106)