MAINTENANCE ALLOCATION CHART (MAC)
SECTION I. INTRODUCTION
B-1. THE ARMY MAINTENANCE SYSTEM MAC.
a. This introduction (Section I) provides a general explanation of all maintenance and repair functions authorized at
various maintenance levels under the standard Army Maintenance System concept.
b. 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.
c. Section III lists the tools and test equipment (both special tools and common tool sets) requircd for each
maintenance function as referenced from Section II.
d. 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:
a. 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. Test. To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical characteristics of
an item and comparing those characteristics with prescribed standards.
c. Service. Operations required periodically to keep an item in proper operating condition; e.g., to clean (includes
decontaminate, when required), to preserve, to drain, to paint, or to replenish fuel, lubricants, hydraulic fluids, or gases.
d. Adjust. To maintain or regulate, within prescribed limits, by bringing into proper position, or by setting the
operating characteristics to specified parameters.
e. Align. To adjust specified variable elements of an item to bring about optimum or desired performance.
f. 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 o' known accuracy, to detect and adjust any discrepancy in the accuracy of the instrument being
g. Remove/Install. To remove and install the same item when required to perform service or other maintenance
functions. Install may be the act of emplacing, seating, or fixing into position a spare, repair part, or module (component
or assembly) in a manner to allow the proper functioning of equipment or system.
h. Replace. To remove an unserviceable item and install a serviceable counterpart in its place. "Replace" is
authorized by the MAC and assigned maintenance level is shown as the 3rd position code of the SMR code.