Figure 3C-119. Pilot Position Page
Table 3C-80. Pilot Position Page Procedure
Pressing PSN function key will access the
pilot position page.
Computed magnetic variation at present
This line select key is non-operational if a
computed wind speed is available or if the
Otherwise, the following three actions will
1. Selection with a valid entry in the
scratchpad will enter the wind.
2. Selection with an empty scratchpad will
copy the wind entry into the scratchpad.
3. Selection with a in the scratchpad will
set the wind speed to 0 knots.
Track displays MAG track.
Navigation source selected on pilot/copilot
lateral steer pages.
The status and validity of the navigational source
is indicated on the title lines of the Pilot Position
pages. Table 3C-81 lists the indications and their
meanings. Any automatic downgrading of the
navigation source is annunciated on the CDU.
A NAV error annunciation and/or the HSI flag
are provided when either the status of the selected
navigation sensors has degraded or the 95% error
exceeds a threshold determined by the current flight
plan guidance mode; EN ROUTE, TERMINAL, or
APPROACH. When these alerts are provided,
examine the current state of the GPS navigation
solution and compare the solution to the other on-
board navigation systems. If necessary, select a
different navigation sensor to provide continued
guidance of the aircraft.
(a) GPS Display. The GPS INAV page
shows the present position output from the GPS
receiver. It also shows a 95% error figure of merit for
the probable system accuracy, given the current GPS
satellite navigational quality (satellite tracking state
and geometry) as shown in Figure 3C-120 and
Table 3C-82. If GPS/A/H is indicated on the title line,
the FMS-800 is using airspeed and heading sensor
inputs to smooth the GPS data. This is required to
have a valid bank (roll) command output to the flight
director and autopilot.
The MODE indicates the current GPS receiver
tracking/aiding mode of INIT, TEST, or NAV/PVA.
The STATE indicates the lowest tracking state of
the four primary satellite tracking channels: STATE 1
is acquisition, STATE 3 is code track only (in
jamming), and STATE 5 is code and carrier lock (no
The number of satellites being tracked for
primary navigational purposes is displayed. Normally
four satellites are tracked to provide a fully determined
position (a four dimensional position requires four
satellites). Less than four may result in GPS's data
Table 3C-81. Display of Navigation Mode on Position Pages
CONDITIONS FOR DISPLAY
GPS navigation data is smoothed with airspeed and heading
GPS/ - /H
GPS navigation data is being smoothed with GPS groundspeed and
GPS/ - / -
GPS is not being smoothed with airspeed and heading data
- - - /A/H
GPS is invalid; FMS is dead reckoning with airspeed and heading data
The model aircraft function is providing the navigation solution. This
function is available only while on the ground.