TM 55-1510-222-10
incorrect. It is possible to force INS to accept updated
position by setting data selector to L/L POS and
proceeding to step 8).
8.
If displayed values are within tolerance,
press HOLD pushbutton to return INS to normal
operation. If one or both values are out of tolerance,
proceed to step 9.
9.
Key 2 - Press.
Observe
left
data
display
is
00000
N;
INSERT/ADVANCE and HOLD pushbutton annunciators
are illuminated.
10. INSERT/ADVANCE pushbutton - Press.
Observe INSERT/ADVANCE and HOLD pushbutton
annunciators extinguish. Present position appears in
data displays. Present position check and update is
complete.
NOTE
Within 30 seconds, computer will
process
correction
and
revised
present position will appear in data
display. If AI prior to position update
is 1 or greater, computer will accept
over 95 percent of correction shown
in difference display. If AI is 0,
amount of correction accepted will
be less and is a function of time in
NAV mode and number of updates
which have been made.
(b) Extra precision geographic present position
check and update:
1.
Data selector - DSRTK/STS.
2.
Key 2 - Press.
Observe INSERT/ADVANCE pushbutton annunciator
illuminates, 000002 appears in right data display.
3.
INSERT/ADVANCE pushbutton - Press.
Observe
right
data
display
is
1--XX2,
INSERT/ADVANCE pushbutton light is extinguished,
and any TACAN, GPS or data link updating is
discontinued.
4.
Data selector - L/L POS.
Observe latitude and longitude of present position
appears in left and right data displays, respectively.
5.
HOLD pushbutton - Press (when aircraft
passes over known position reference.) Observe HOLD
pushbutton annunciator illuminates. Latitude and
longitude in data displays freeze at values present when
HOLD pushbutton was pressed.
6.
Load latitude by pressing keys in
sequence, starting with N or S to indicate north or south.
Example: 42° 54.0' North = N 4 2 5 4 0. Observe
latitude appears in left data display as keys are pressed.
7.
INSERT/ADVANCE pushbutton - Press,
observe INSERT/ADVANCE and HOLD pushbuttons
remain illuminated.
8.
Load longitude by pressing keys in
sequence, starting with W or E indicating west or east.
Example: 87°
54.9' West = W 8 7 5 4 9.
9.
INSERT/ADVANCE pushbutton - Press.
Observe INSERT/ADVANCE and HOLD pushbutton
annunciators remain illuminated.
10. INSERT/ADVANCE pushbutton - Press.
Observe arc-seconds related to present position latitude
and longitude, to nearest tenth of a second, appear in
left and right data displays, respectively.
11. Load related arc-second values for
latitude in sequence, starting with N.
Example: 35.8° North = N 3 5 8.
12. INSERT/ADVANCE pushbutton - Press.
Observe INSERT/ADVANCE and HOLD pushbuttons
remain illuminated.)
13. Load related arc-second values for
longitude in sequence, starting with E.
Example: 20.1° East = E 2 0 1.
3-61
