Fire Control Instrument Operator, Field Artillery (645) Enlisted Personnel

Prepares firing chart for vertical and horizontal control, using protractor scale and straightedge showing battery positions, check points, base points, targets, elevations, front lines, minimum and maximum ranges, and zones or sectors of supported units.
Performs any one or more of the following operations: calculates distances between points, calculates coordinates from field notes, converts degrees and minutes to mils, calculates elevation, reads horizontal angles between guns to targets and other points, interprets metro message, calculates correction factors for wind and weather components, or alerts firing battery by telephone and receives and transmits fire orders. In a firing battery, sets up and operates such fire control instruments as aiming circle and range finder. Performs survey operations when required.
Uses a special Manheim type slide rule called graphical firing table to assist battery, battalion, or higher commander in making trigonometric and ballistic calculations to obtain data for the preparation and conduct of artillery fire.

Alternate nomenclatures:

• Computer, Fire Director
• Horizontal Operator
• Vertical Operator