TM-9-2350-311-10

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; OPERATOR’S MANUAL

NOVEMBER 1994

TM-9-2350-311-10 - Page 486 of 775

TM 9-2350-311-10

3-7 FIRE CONTROL ALINEMENT TESTS AND MEASUREMENTS — CONTINUED

3-7.1

General —Continued

c. Preparation for Fire Control Alinement Tests

1

2

3

4

5

6

7

Emplace the weapon on as firm and level ground as is possible. Use hard stand if one is available.

Check the M15 elevation quadrant, the M117/M117A2 panoramic telescope, and the M145/M145A1

telescope mount for looseness or other obvious defects. Make sure M117/M117A2 panoramic telescope

is securely mounted using both latches. Make sure M140 alinement device is securely mounted in front

of panoramic telescope ballistic cover.

Inspect the M1A1 gunner’s quadrant shoes for dirt or burrs. If necessary, clean the shoes with a wiping

rag (item 35, Appx D). If burrs are present, notify unit maintenance.

Perform M1A1 gunner’s quadrant tests (para 3-7.2).

Level the gun trunnions (para 3-7.3).

Zero the cannon tube.

If necessary check the stability of the cannon assembly (cannon tube drop).

(a) Using the M1A1 gunner’s quadrant, place cannon tube at + 266 mils.

(b) Turn CAB POWER switch to OFF and wait 1 hour.

(c) Cannon tube should not have moved more than 3.0 mils. If greater movement is found, notify unit

maintenance.

(d) Repeat steps (b) and (c) placing cannon tube at+ 600 mils.

(e) Boresight the weapon (para 2–12.2).

3-82