TM 1-1520-238-10
Change 8
3-64.5
Line 2. – The left–hand character field displays the legend
VAR followed by the PPOS MAGVAR in degrees. If the
INS is NO–GO, an outlined arrow ( ) will be displayed im-
mediately to the left of VAR permitting manual MAGVAR
updates. The right–hand character field displays the leg-
end D followed by the PPOS Datum number.
Line 3. – The left–hand character field displays the legend
BRG XXXDEG reflecting the direct bearing to the destina-
tion specified in the FLY TO legend. The BRG legend is a
read–only display. The right–hand character field displays
the legend ADMIN. An outlined arrow ( ) following
ADMIN indicates the ability to select the ADMIN page for
display.
Line 4. – The left–hand character field displays the legend
DIST XXX.XKM. DIST is displayed in KM (kilometers)
when the coordinate system in use is metric, and in NM
(nautical miles) when the coordinate system in use is nau-
tical. The display uses a floating decimal point allowing a
distance accuracy of 10 meters (32 feet) when DIST is
less than 100 KM units. The DIST numerals are updated
at the rate of 1Hz regardless of aircraft speed. The right–
hand character field displays the legend TTG X:XX to the
FLY–TO destination in Hours and Minutes (H:MM). When
less than five (5) minutes from destination, these units
change to Minutes and Seconds (M:SS). If TTG to the
FLY TO exceeds 9 hours and 59 minutes, or the aircraft
groundspeed is less than 10 knots, the display is dashed.
Both of the character fields are read–only and cannot be
edited.
Line 5. – Displays the legend TKA XXXDEG and GS
XXXKPH. TKA denotes the computed Track Angle, in De-
grees (DEG), while GS reflects Ground Speed. GS is pre-
sented in Kilometers Per Hour (KPH) or Knots (KTS) de-
pendent on display selected. The units for both DIST and
GS are the same for a given selection: KM and KPH, or
NM and KTS.
Line 6. – Displays the System Annunciator Data which
consists of three elements: A DNS Memory (MEM) ele-
ment; a Navigation Status (NAV STAT 1–3) element; and
a Check FDLS ( FDLS) element. These status mes-
sages may appear at any time on this line. A display on
this line indicates that the DNS has either lost radar lock
(MEM); the navigation error exceeds certain parameters
(NAV STAT 1–3); or, the Continuous FDLS test has de-
tected a fault in the system FDLS). Navigation Status
categories are as follows:
NAV STAT 1: Estimate of position error calculation is less
than 50 meters. Actual position error may be substantially
less. PPOS updates are disabled.
NAV STAT 2: Estimate of position error calculation at least
50 meters but less than 201 meters. Actual position error
may be substantially less. All PPOS update operations
are enabled.
NAV STAT 3: Estimate of position error calculation is
greater than 200 meters. Actual position error may be
substantially less. All PPOS update operations are en-
abled.
Line 7. – The left–hand character field displays the legend
FLY TO TXX or FLY TO WXX, depending upon the se-
lected destination to which the system is navigating. The
displayed value can be any of the 40 waypoint locations in
the FPLN List; or any of the 40 target locations. UPD TO
WXX displayed indicates the destination to which the sys-
tem is being updated. The right–hand character field dis-
plays the legend STR WXX representing the waypoint
number (from 31–40) to be used by the system for the
next PPOS store.
Line 8. – This is the scratchpad line for manual data entry.
