software is installed go to paragraph
3.16 for Waypoint/Targeting system descrip-
tion and operation.
Waypoint/targeting functions are performed solely by the
CPG. The pilot cannot actively participate. Four functions
can be implemented. These are: preflight, storing, posi-
tion update, and cueing.
4.17.1 Waypoint/Targeting Data Entry.
point/targeting function requires certain data. The data is
input using both the TGT and SP1 positions on the DEK
rotary switch. The data entered under SP1 is displayed as
a menu with two pages. They are:
HH: MM: SS
11S QG 5551 5221
+AAAA HG: 29.92IN.
a. Data Entry.
To enter data input the first character
of the desired parameter. The cursor will jump to the first
digit position of the data, then input the full data required.
On completion the data will be automati cally entered.
The LAT/LONG conversion process within
the FCC contains nonlinear transformation
errors in accordance with the table below:
0 to 34
Less than 2 meters
35 to 44
Less than 50 meters
45 to 54
Less than 1100 meters
55 to 63
Less than 2000 meters
64 and up
More than 2000 meters
(1) FCC Present Position Data.
The FCC pres-
ent position (PPOS) data are used only for the initial align-
ment of the HARS when the helicopter is on the ground.
The present position shall be entered prior to a normal or
fast alignment of the HARS. It is not required for a stored
heading alignment or inflight restart. The accuracy of the
present position input should be within 500 750 meters,
straight line distance, from the actual location. Inflight this
display will periodically update reflecting the doppler pres-
ent position. The doppler display updates at a substantial-
ly higher rate than the PPOS display, consequently there
may not be any correlation of the doppler and PPOS dis-
play in forward flight. This is normal and does not indicate
a problem condition. If at any time ?? appear following the
PPOS data, as shown in the example, the FCC is rejecting
the doppler navigation data as being in error. This may be
an indication of doppler malfunction or that the doppler
has not been updated recently. The displayed PPOS data,
in this case, will then reflect the best computed present
position based on HARS velocity data.
(2) Altitude and Altimeter Data.
and altimeter setting data are to be used in the following
manner: Altitude above mean sea level shall be entered
when the aircraft is on the ground. The value is deter-
mined from referring to navigational charts or by tactical
map study. The Fire Control System will compute the cor-
responding altimeter setting. The altimeter setting shall be
entered when the aircraft is in flight. The altitude display
may be observed in flight; if an error exists in the dynamic
altitude display when compared to the aircraft barometric
altimeter, the altimeter setting should be entered. The al-
timeter setting can normally be obtained from a local air
traffic control agency. In the event of a failure of the air
data sensor, question marks, ??.??, will be displayed in
the altimeter setting display. The fire control system will at-
tempt to derive the aircraft altitude above mean sea level
by adding radar altitude to the last valid altitude value dis-
played. The altitude value should then be periodically up-
dated in flight. The altitude value computed from radar al-
titude is accomplished based on standard atmosphere.
(3) Time Display Functions.
The TIME display
functions only when power is applied to the fire control
computer. The TIME display is not part of the backup bus
controller software. The TIME display will increment from
whatever time value is entered; on initial power up the
TIME value is zero. If a TIME value of 00:00:00 is input,
the TIME display will function as an elapsed time clock.
The TIME display is a twentyfour hour clock with an ac-
curacy of plus or minus 1 second while running.