MAINTENANCE ALLOCATION CHART (MAC)
SECTION I. INTRODUCTION
THE ARMY MAINTENANCE SYSTEM MAC.
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.
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 0 (unit) maintenance.
Direct Support includes an F subcolumn.
General Support includes an H subcolumn.
Depot includes a D subcolumn.
Section III lists the tools and test equipment
(both special tools and common tool sets) required for
each maintenance function as referenced from Section
Section IV contains supplemental instructions
and explanatory notes for a particular maintenance
Maintenance functions are limited to and defined as
Inspect. To determine the serviceability of an
item by comparing its physical, mechanical, and/or
electrical characteristics with established standards
Test. To verify serviceability and to detect
incipient failure by measuring the mechanical or
electrical characteristics of an item and comparing those
characteristics with prescribed standards.
Service. Operations required periodically to
keep an item in proper operating condition, i.e., to clean
(includes decontaminate, when required), preserve,
drain, paint, or to replenish fuel, lubricants, chemical
fluids, or gases.
Adjust. Maintain or regulate, within prescribed
limits, by bringing into proper or exact position, or by
setting the operating characteristics to specified
Calibrate. To determine the cause and
corrections to be made or adjusted on instruments or
test measuring and diagnostic equipment used in
precision measurement. This 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.
Replace. To remove an unserviceable item and
install a serviceable counterpart in its place. Replace is
authorized by the MAC and is shown as the third
position code of the SMR code.
Repair. The application of maintenance
removal/installation, disassembly/assembly procedures3,
and maintenance actions4 to identify troubles, and
restore serviceability to an item by correcting specific
damage, fault, malfunction, or failure in a part,
subassembly, module (component or assembly), and
item or system.
1 Services Inspect, test, service, adjust, align, calibrate,
investigating and detecting the cause of equipment
malfunctioning; the act of isolating a fault within a
system or unit under test (UUT).
3 Disassembly/assembly The step by step breakdown
(taking apart) of a spare/functional group coded item to
the level of its least component, that is assigned an
SMR code for the level of maintenance under
consideration (i.e., identified as maintenance
Actions Welding, grinding, riveting, straightening,
facing, machining, and/or resurfacing.