TM 9-1220-238-14
APPENDIX C
MAINTENANCE ALLOCATION CHART (MAC)
Section I. INTRODUCTION
correcting specific damage, fault, malfunction, or failure
C -1. General.
in a part, disassembly, module/component/assembly
This Maintenance Allocation Chart designates
end item or system
overall responsibility for the performance of
j.
Overhaul.
That maintenance effort
maintenance functions on the board plotting M18. The
(service/action) necessary to restore an item to a
implementation of field maintenance tasks upon this
completely
serviceable/operational
condition
as
plotting board will be consistent with the assigned
prescribed by maintenance standards (e.g., DMWR) in
maintenance operations
pertinent technical publications. Overhaul is normally
the highest degree of maintenance performed by the
C-2. Maintenance Functions.
Army Overhaul does not normally return an item to like
Maintenance functions will be limited to and
new condition
defined as follows:
k. Rebuild. Consists of those services/actions
a. Inspect. To determine the serviceability of
necessary for the restoration of unserviceable
an item by comparing its physical, mechanical and/or
equipment to a like new condition In accordance with
electrical characteristics with established standards
original manufacturing standards Rebuild is the highest
through examination.
degree of material maintenance applied to Army
b. Test. To verify serviceability and detect
equipment. The rebuild operation includes the act of
incipient failure by measuring the mechanical or
returning to zero those age measurements (hours/miles
electrical characteristics of an item and comparing those
etc)
considered
in
classifying
Army
characteristics with prescribed standards.
equipments/components
c. Service. Operations required periodically to
l. Symbols. The uppercase letter placed in the
keep an end item in proper operating condition, i e., to
appropriate column indicates the lowest level at which
clean, to preserve, to drain, to paint, or to replenish fuel,
that particular maintenance function is to be performed.
lubricants, hydraulic fluids, or compressed air supplies.
d. Adjust. To maintain, within prescribed
C-3. Explanation of Format.
limits, by bringing into proper or exact position, or by
Purpose and use of the format are as follows
setting the operating characteristics to specified
and will be explained in the introductory portion of the
parameters.
MAC.
e. Align. To adjust specified variable elements
a. Column 1. Group Number. Column 1, lists
of an item to bring about optimum or desired
group numbers, the purpose of which is to identify
performance.
components, assemblies, subassemblies, and modules
f.
Calibrate.
To determine and cause
with the next higher assembly
corrections to be made or to be adjusted on instruments
b. Column 2. Functional Group. Column 2,
or test measuring and diagnostic equipments used in
lists the next higher assembly group and the item names
precision measurement. Consists of comparisions of
of components, assemblies, subassemblies, and
two instruments, one of which is a certified standard of
modules within the group or which maintenance is
known accuracy, to detect and adjust any discrepancy in
authorized.
the accuracy of the instrument being compared.
c.
Column 3.
Maintenance Functions.
g. Install. The act of emplacing, seating, or
Column 3, lists the twelve maintenance functions
fixing into position an item, part, or module (component
defined in C-2 above. Each maintenance function
or assembly) in a manner to allow the proper functioning
required for an item shall be specified by the symbol
of an equipment or system.
among those listed in d below which indicates the level
h.
Replace.
The act of substituting a
responsible for the required maintenance Under this
serviceable like type part, subassembly, or module
symbol there shall be listed an appropriate work
(component or assembly) in a manner to allow the
measurement time value determined as indicated in e
proper functioning of an equipment/system.
below.
i. Repair. The application of maintenance
d. Use of Symbols. The following symbols will
services (imput, test, service, adjust, align, calibrate,
replace) or other maintenance actions (welding,
grinding, riveting, straightening, facing, remachining, or
resurfacing) to restore serviceability to an item by
C-1
