TM 10-4320-303-13
APPENDIX B
MAINTENANCE ALLOCATION CHART (MAC)
SECTION I.
INTRODUCTION
B.1 THE ARMY MAINTENANCE SYSTEM MAC .
B.1.1 Introduction. This introduction (Section I) provides a general explanation of all levels of maintenance
and repair functions authorized at various maintenance levels under the standard Army Maintenance System
concept.
B.1.2 Maintenance Allocation Chart Section II . The Maintenance Allocation Chart (MAC) in section II
designates overall authority and responsibility for the performance of maintenance functions on the identified
end item or component. The application of the maintenance functions to the end item or component will be
consistent with the capacities and capabilities of the designated maintenance levels, which are shown on the
MAC in column (4) as:
Unit - includes two subcolumns, C (operator/crew) and O
(unit) maintenance
Direct support - includes an F subcolumn
General support - includes an H subcolumn
Depot - includes a D subcolumn
B.1.3 Tools and Test Equipment Introduction . Section III lists the tools and test equipment (both special
tools and common tool sets) required for each maintenance function as referenced from section II.
B.1.4 Supplemental Instructions Introduction . Section IV contains supplemental instructions and
explanatory notes for a particular maintenance function.
B.2 MAINTENANCE FUNCTIONS .
Maintenance functions are limited to and defined as follows:
B.2.1 Inspect. To determine the serviceability of an item by comparing its physical, mechanical, and/or
electrical characteristics with established standards through examination (e.g., by sight, sound, or feel).
B.2.2 Test. To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical
characteristics of an item and comparing those characteristics with prescribed standards.
B.2.3 Service. Operations required periodically to keep an item in proper operating condition, i.e., to clean
(includes decontaminate, when required), to preserve, to drain, to paint, or to replenish fuel, lubricants,
chemical fluids, or gases.
B.2.4 Adjust. To maintain or regulate, within prescribed limits, by bringing into proper or exact position, or by
setting the operating characteristics to specified parameters.
B.2.5 Align. To adjust specified variable elements of an item to bring about optimum or desired performance.
B.2.6 Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test,
measuring, and diagnostic equipment used in precision measurement. Consists of comparisons of two
instruments, one of which is a certified standard of known accuracy, to detect and adjust any discrepancy in the
accuracy of the instrument being compared.
B-1
