Fire Direction Center Procedures.

TM 9-6920-361-13&P

(3) Air observer (AO) training can be

(a)

Battery emergency mission

conducted using a helicopter. The aircraft should fly at

(b)

High burst registration

an altitude of about 200 feet to the rear of the firing

(c)

Mean-point-of-impact registration

position. The AO should be given *shot' ten seconds

(d)

Precision impact registration

before the weapons fire, in order to properly position the

(e)

Destruction mission

aircraft for observation.

(f)

MET plus VE fire for effect

(g)

High-angle

battalion

mass

Fire Direction Center Procedures.

mission

(h) Battalion TOT

(i) Coordinated illumination mission

(1) Manual solution.

Those missions that cannot be conducted are time

(a) The 1:25, 000 scale grid sheet is

transfers and area time adjustments.

set up in the same manner as for firing the main tube

except that the space between grid lines is 1, 000

(2) During the march from the rendezvous

decimeters.

area to a firing position (or from one firing position to

(b) The target grid is oriented in the

another), an emergency mission may be conducted if the

same manner as with other field artillery weapons. The

14.5-mm barrel has been previously installed and

horizontal control operator (HCO) plots the target using

boresighted (para. 2-7 through 2-10.1). The emergency

the 1:25, 000 coordinate scale and determines chart data

mission position may become a primary position

(range and deflection) using the 1:25, 000 scale range-

requiring

survey,

communication,

and

other

deflection protractor or using the graphical firing table

improvements.

(GFT) fan determine deflection and elevation. The

vertical control operator (VCO) determines site using the

(3) During a battalion exercise the survey

special map and the 14.5-mm graphical site table (GST).

party may establish an 01-02 base. If the point selected

for the MPI or HB is about 300 meters down range, then

determined in feet or meters, it must be converted to

the length of the base should be 60 to 100 meters. A

decimeters. For example, if the difference in altitude is

good rule to follow is that the length of the base should

31.2 meters, the VCO would use 312 decimeters as the

be no less than 1/5 the observing range. Care should be

vertical interval (VI) and the range announced by the

exercised when selecting the 01-02 base; make sure that

HCO to determine site. Instructions and examples on

the guns do not fire over the personnel occupying the 01-

GST usage are printed on the back of the GST. The

02 base.

computer, using the 14.5-mm graphical firing table

(GFT), computes the gun data and announces the fire

NOTE

commands to the guns.

(d) Because of short range of the

Do not apply registration corrections

14.5-mm trainer, small vertical differences, such as one

obtained from a HB registration to

or two meters, equate to several meters in range.

subsequent firing data.

Do not

Therefore, in order to obtain valid corrections when

attempt to transfer fire using the 3-or

conducting a registration, the height of the barrel above

6-second delay round.

the surveyed battery center should be considered.

When constructing a firing chart the surveyed altitude of

(4) When conducting a high burst

the battery should be increased the following amount.

registration, you can use either the 3-second or 6-second

Model

Howitzer

Decimeters

delay round. The chart location of the high burst will be

M101A1

105-mm

+10

at the appropriate deflection and at a GT range

M102

105-mm

+10

corresponding to 3or 6seconds. This plot will provide

M114A1

155-mm

+15

orienting data for 01 and 02. The quadrant elevation

M109/M109A1

155-mm

+20

fired should correspond to a time of flight 0.6 seconds

M110

8-inch

+20

greater than the present time (3 or 6 seconds) of the

M107

175-mm (Gun)

+20

round. Eight rounds will normally provide sufficient data

M198

155-mm

+20

to obtain corrections.

(2) FADAC Solution. The M18 FADAC tape

(revision 5) will be utilized for the FADAC solution.

d. Mission Procedures.

(1) During practice for unit ATT/ORTT, the

following missions may be conducted using the M31:

Change 1 2-24