TM 9-1330-200-12/OP 3833 1st Rev. Vol 2/TM 1330-12/1A
MAINTENANCE ALLOCATION CHART (MAC)
Section I. INTRODUCTION
known accuracy, to detect and adjust any discrepancy in
accuracy of the instrument being compared with the
a. The MAC assigns authorized maintenance
functions to each maintenance category. Maintenance
functions are assigned to the lowest maintenance
category, as warranted by past experience in the
unserviceable parts or components.
h. REPLACE. To replace unserviceable items with
(1) Skills available.
serviceable assemblies, subassemblies, or parts.
(2) Man hours available vs. Maintenance
i. REPAIR. To restore an item to serviceable
function manhour requirements.
condition through correction of a specific failure or
(3) Tools and test equipment authorized.
To restore an item to a
b. The basic entries on the chart list functional
completely serviceable condition as prescribed by
groups applicable to the end items which may require
maintenance serviceability standards.
maintenance parts. The term functional group applies
to assemblies and subassemblies but not to piece parts.
k. REBUILD. To restore an item, as nearly as
Entries are brief, general descriptions without stock or
possible, to original or new condition: in appearance,
part numbers, in order to minimize need for subsequent
performance and life expectancy. This is accomplished
change; however, entries permit positive identification.
through the maintenance technique of complete
disassembly of the item, inspection of all parts or
C-2. Maintenance Functions
components, replacement of unserviceable elements,
Maintenance functions are limited to and defined as
and subsequent reassembly of the item.
a. INSPECT. To determine serviceability of an
l. SYMBOLS. The uppercase letter placed in the
item by comparing its physical, and mechanical
appropriate column indicates the lowest level at which
characteristics with established standards.
that particular maintenance function is to be performed.
b. TEST. To verify serviceability and to detect
C-3. Explanation of Format
Purpose and use of the format are as follows:
mechanical failure by use of test equipment.
a. Column 1, Group number. Column 1 lists group
c. SERVICE. To clean and to preserve. If it is
numbers, the purpose of which is to identify
desired that elements, such as painting and lubricating,
components, assemblies, subassemblies and modules
be defined separately, they may be so listed.
with the next higher assembly.
d. ADJUST. To rectify to the extent necessary to
b. Column 2, Functional group. Column 2 lists the
bring into proper operating range.
noun names of components, assemblies, subassemblies
e. ALIGN. To adjust specified variable elements
and modules on which maintenance is authorized.
of an item to bring to optimum performance.
f. CALIBRATE. To determine corrections to be
made in readings of instruments or test equipment used
in precise measurement. Consists of comparison of two
instruments, one of which is a certified standard of