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 485 of 775
TM 9-2350-311-10
3-7 FIRE CONTROL ALINEMENT TESTS AND MEASUREMENTS
3-7.1
General
a. Intervals
Fire control alinement tests are performed by the section crew members under the supervision of the battery executive
officer, chief of firing battery, and artillery mechanic. These tests are performed at the discretion of the unit commander.
Suggested intervals for these tests are as follows.
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Once each year if the cannon is used for non-firing training.
Once every 3 months if the cannon is fired.
As soon as possible after extensive use.
Following accidents.
After traveling over extremely rough terrain.
When fire control mounts have been replaced.
When the cannon fires inaccurately for no apparent reason.
When the cannon tube is replaced.
b. Equipment Required for Fire Control Alinement Tests
Equipment necessary for performing the fire control alinement tests is as follows.
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Three 10-ton jacks.
A cord at least 22 feet (67 m) long with an object that weighs at least 1/2 pound (0.23 kg) tied to the end.
Muzzle crosshairs.
Breech boresight disc.
M1A1 gunner’s quadrant.
Test target.
Three to five gallon (18.91) container of waste oil or water.
Three inch (7.62 cm) screwdriver for boresighting M117/M117A2 panoramic telescope.
Cannon tube leveling fixture (bar) when required.
3-81
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