USArmy-ApacheLongbow

TM 1-1520-251-10
3A.81.3 ALIGN STATIONARY (STAT) Button. The
ALIGN STAT button is displayed only when the state of
the NAV mode button is set to SEA and the primary and/or
secondary INU has a position from the GPS or has been
manually entered and that it is ready to initiate a stationary
navigation system alignment.
3A.81.4 ALIGN MOVE Button. The ALIGN MOVE button
displayed only when the state of the NAV mode button is
set to SEA and the primary and/or secondary INU has a position
from the GPS or has been manually entered and that it is
ready to initiate a moving navigation system alignment.
These are only displayed when on the ground in SEA mode.
3A.81.5 DOPPLER Button. The DOPPLER button enables
or disables the Doppler.
3A.81.6 ASE AUTOPAGE Button.
The ASE AUTO-
PAGE button is used to select the state or condition of an
acquiring threat system which causes autopaging of
threat warning information. The ASE AUTOPAGE is
crewstation independent. The available selections are:
• SEARCH
• ACQUISITION
• TRACK
• OFF
3A.81.7 TIME Button. The TIME button sets the display
mode of time to LOCAL or ZULU.
3A.81.8 SYSTEM TIME Button. The SYSTEM TIME
button sets the current LOCAL or ZULU time. The ZULU
time must be entered before the LOCAL time. When a ZULU
System Time is entered, the system processor sets its clock
to the entered time, and sends this time to the respective primary
and secondary EGIs if their respective GPS is not tracking
enough satellites. To determine if the GPS used the time,
monitor the Satellite Status window. If the time entered is
used, the respective GPS Satellite ID numbers in the Satellite
Status window, will momentarily blank, then reappear.
3A.81.9 SYSTEM DATE Button. The SYSTEM DATE
button sets the current date. When a system date is entered,
the system processor sets its Date to the entered
system date, and sends this date to the respective primary
and secondary EGIs if their respective GPS is not tracking
enough satellites. To determine if the GPS used the date,
monitor the Satellite Status window. If the date entered is
used, the respective GPS Satellite ID numbers in the Satellite
Status window, will momentarily blank, then reappear.
3A.81.10 DATUM Button. The DATUM button allows
entry of a new datum in place of the default datum entered
at the mission planning station. If the pilot enters a D using
the KU, the system returns to the default datum and automatic
datum updates, based on the current waypoints and
their datums in the current route being flown.
NOTE
When the INU is reset or power is applied to
the INU, the MPD will not display symbols
that use INU information until the INU determines
that its data is valid.
3A.81.11 Navigation (NAV) Mode Button. The NAV
mode button selects the navigation mode: (LAND or SEA)
The primary System Processor (SP), upon generator power
up, automatically controls initialization and alignment of the
EGIs of the aircraft. Upon system power up, the last NAV
mode stored LAND or SEA, at power down will be selected
automatically by the SP. The flight crew should confirm the
correct moding of LAND or SEA (SEA-Stationary or Moving)
for the initialization/alignment process based on the current
aircraft configuration. After takeoff, (in-flight) the Navigation
Mode switch is used to select LAND or SEA using the criteria
of where the aircraft is to be primarily operated for the mission.
The LAND mode is used when operating primarily over
terrain. The SEA mode is used when operating primarily over
water. When the LAND or SEA mode selection is made inflight,
there will be no apparent change to the flight crew (with
the exception of the displayed LAND or SEA mode) but the
navigation system will change the weighting of the Doppler
velocity data to provide the best navigational accuracy (most
significantly during degraded navigation modes).
3A.81.12 POSITION CONFIDENCE Status Window.
The POSITION CONFIDENCE status window in
the upper area of the page presents position confidence
status for INU1 and INU2. This value represents the 95%
probable radial position error of the position estimate of
latitude and longitude. It is displayed in WHITE when the
value is greater than 50 meters, FAILED, or when the INU
is not installed.
3A.81.13 DOPPLER DATA Status Window. The DOP-
PLER DATA status window provides the Doppler aiding
status of INU1 and INU2: USED, REJECTED (WHITE), or
MEMORY (WHITE).
Use or disclosure of this information is subject to the restriction(s) on the title page of this document.
Change 2 3A-117