C3, TM 9-2320-211-20
MAINTENANCE ALLOCATION CHART
Section I. INTRODUCTION
B-1. General.
h. Replace. The act of substituting a serviceable like
type part, subassembly, or module (component or
a. This section provides a general explanation of all
assembly) for an unserviceable counterpart.
maintenance and repair functions authorized at various
maintenance levels.
i. Repair. The application of maintenance services' or
other maintenance actions2 to restore serviceability to an
b. The Maintenance Allocation Chart (MAC) in
item by correcting specific damage, fault, malfunction, or
section II designates overall responsibility for the
failure in a part, subassembly, module (component or
performance of maintenance functions on the identified
assembly), end item, or system.
end item or component. The implementation of the
maintenance functions upon the end item or component
j. Overhaul. That maintenance effort
will be consistent with the assigned maintenance
(services / actions) necessary to restore an item to a
functions.
c o m p l e t e l y serviceable/operational condition as
prescribed by maintenance standards (i.e., DMWR) in
appropriate technical publications. Overhaul is normally
the highest degree of maintenance performed by the
Army. Overhaul does not normally return an item to like
a. lnspect. To determine the serviceability of an item
new condition.
by comparing its physical, mechanical, and/or electrical
characteristics with established standards through
k. Rebuild. Consists o f those services/actions
examination.
necessary for the restoration of unserviceable equipment
to a like new condition in accordance with original
b. Test. To verify serviceability and detect incipient
manufacturing standards. Rebuild is the highest degree
failure by measuring the mechanical or electrical
of material maintenance applied to Army equipment.
c h a r a c t e r i s t i c s of an item and comparing those
The rebuild operation includes the act of returning to
characteristics with prescribed standards.
z e r o those age measurements (hours/miles, etc.)
considered in classifying Army equipments/components.
c. Service. Operations required periodically to keep an
item in proper operating condition, i.e., to clean
B-3. Column Entries Use in the MAC.
(decontaminate), to preserve, to drain, to paint, or to
replenish fuel, lubricants, hydraulic fluids, or compressed
a. Column 1, Group Number. Column 1 lists group
air supplies.
numbers, the purpose of which is to identify components,
assemblies, subassemblies, and modules with the next
d. Adjust. To maintain, within prescribed limits, by
higher assembly.
bringing into proper or exact position, or by setting the
operating characteristics to specified parameters.
b. Column 2, Component/Assembl.v. Column 2
c o n t a i n s the names of components, assemblies,
e. Aline. To adjust specified variable elements of an
subassemblies, and modules for which maintenance is
item to bring about optimum or desired performance.
authorized.
f. Calibrate. To determine and cause corrections to be
c. Column 3, Maintenance Functions. Column 3 lists
made or to be adjusted on instruments or test measuring
the functions to be performed on the item listed in
a n d diagnostic equipments used in precision
column 2. (For detailed explanation of these functions,
measurement. Consists of comparisons o f t w o
see para B-2.)
instruments, one of which is a certified standard of
known accuracy, to detect and adjust any discrepancy in
d. Column 4, Maintenance Level. Column 4 specifies,
the accuracy of the instrument being compared.
by the listing of a "work time" figure in the appropriate
subcolumn(s), the lowest level of maintenance authorized
g. Install. The act of emplacing, seating, or fixing into
to perform the function listed in column 3. This figure
position an item, part, or module (component or
represents the active time required to perform the
assembly) in a manner to allow the proper functioning of
m a i n t e n a n c e function at the indicated level of
an equipment or system.
maintenance. If the number or complexity of the tasks
l
Services-inspect, test, service, adjust, aline, calibrate, or replace.
2
Action--welding, grinding, riveting, straightening, facing, remachining, or resurfacing.
