(5)
(6)
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747-400 MAINTENANCE MANUAL
(b)
Stations (STA)
(c)
Waypoints (WPT)
(d)
Airports (ARPT)
(e)
DATA
(f)
Position (POS)
In addition to the above EFIS CP selection there also exists VOR/ADF
switches. These switches allow for the display of vectors extending
from the airplane through the selected navaid as well as displaying
corner information for the navaid.
ND/FMCS Displays (Fig. 28)
(a) The ND can display two mode configurations selected through the EFIS CP. These modes are MAP mode and plan (PLN) mode. 1) MAP mode displays the current airplane position with respect to the predetermined flight plan. This includes waypoints, navaids, airports and the their corresponding data . It also displays wind direction and speed, track, heading, trend vector and navaid corner information. This information can be displayed in two formats selected on the EFIS CP. These are center MAP which displays a full rose compass and MAP mode which displays a half rose compass. 2) There are two types of data transmitted from the FMCS to the ND MAP mode display. These are dynamic and background data. a) Dynamic data is that data which keeps the ND displaying the current airplane position with respect to the flight plan data. It also consists of data which changes continuosly such as wind, ground speed and heading. b) Background data is defined as that data which is in the flight plan, optional data selected for display, and advisory messages. This includes data such as waypoints, airports, navaids, procedure turns and all related data. 3) PLAN mode displays the lateral profile of the predetermined flight path. Waypoints, procedure turns and destination airports will be displayed in a north up reference. A track or heading tape will be displayed at the top of the display along with the estimated time of arrival (ETA) and the distance to go to the next waypoint.
PFD/FMCS Displays (Fig. 29)
(a) The majority of the PFD data supplied by the FMC is related to airplane speed. Other data supplied by the FMC is the autothrottle mode for annunciation purposes. The speed related data consists of the following: 1) Decision speed 2) Maximum maneuvering speed 3) Minimum maneuvering speed 4) Take-off climb speed (V1) 5) Rotate speed (VR) 6) Reference speed (VREF)
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747-400 MAINTENANCE MANUAL
(b)
These speed parameters will be displayed on the speed tape located on the left side of the PFD.
(c)
The autothrottle mode annunciator will be displayed on the upper left corner of the PFD.
6. Navigation (Fig. 30)__________
A. General
(1)
The FMC's navigation function provides airplane present postion and velocity data. This data is used by the guidance function for airplane control and the IDS for display on the ND.
(2)
The basic navigational output data is computed using optimally mixed inputs of:
(a)
IRS's position, velocity, heading and altitude data
(b)
Data from the FMCS Navigational Data Base (NDB)
(c)
Distance information from the two DMEs
(d)
Bearing information from the two VORs
(e)
Altitude and true airspeed data from the Air Data Computer (ADC)
(f)
ILS localizer and glideslope deviation data when the airplane is in the approach mode.
(3)
This information is combined and filtered by the FMC to produce the following navigation outputs:
(a)
Airplane position (latitude and longitude)
(b)
Track angle
(c)
Wind vectors (north and east wind components, wind magnitude, wind bearing, tail wind and crosswind)
(d)
Baro-corrected altitude
(e)
Airplane velocity (ground speed)
(f)
Local earth radius
(4)
The FMC will control the tuning of navaids as well as directing navaid information into channels (memory slots) while in autotune. The FMC uses the NDB to select the navaids which will be tuned. The FMC also directs the navaid information into DME channels in a logical manner to obtain the best VHF NAV radio positioning mode. These VHF NAV radio positions are then combined with the mixed inertial position from the IRSs to obtain the best positioning mode. These nav modes are listed in order of preference:
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