TM 55-4920-231-14
M A I N T E N A N C E ALLOCATION CHART
1. PURPOSE.
The purpose of the Maintenance Allocation Chart is to provide all activities with maintenance func-
tions to be performed at each level of maintenance.
2. DEFINITIONS.
a. Column 1, Group Number. Column 1 lists group numbers, the purpose of which is to identify
components, assemblies subassemblies, and modules with the next higher assembly.
b. Column 2, Functional Group. Column 2 lists the noun names of components, assemblies, subas-
semblies, and modules on which maintenance is authorized.
c. Column 3, Maintenance Functions. Maintenance functions will be limited to and defined as foil-
lows:
(1) Inspect. To determine serviceability of an item by comparing its physical, mechanical, and
electrical characteristics with established standards.
(2) Test. To verify serviceability and to detect electrical or mechanical failure by use of test equip-
ment.
(3) Service. To clean, to preserve, to charge, and to add fuel, lubricants, cooling agents, and air.
If it is desired that elements, such as painting and lubricating, be defined separately, they may be so
listed.
(4) Adjust. To rectify to the extent necessary to bring into proper operating range.
(5) Align. To adjust specified variable elements of an item to bring to optimum performance.
(6) Calibrate. To determine the corrections to be made in the readings of instruments or test
equipment used in precise measurement. Consists of the comparison 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 with the certified standard.
(7) Install. To set up for use in an operational environment such as an emplacement, site, or ve-
hicle.
(8) Replace. To replace unserviceable items with serviceable assemblies, subassemblies, or parts.
(9) Repair. To restore an item to serviceable condition. This includes, but is not limited to, in-
spection, cleaning, preserving, adjusting, replacing, welding, riveting, and strenthening.
(10) Overhaul. To restore an item to a completely serviceable condition as prescribed by mainten-
ance serviceability standards prepared and published for the specific item to be overhauled.
(11) Rebuild. To restore an item to a standard as nearly as possible to original or new condition in
appearance, performance, and life expectancy. This is accomplished through complete disassembly of
the item, inspection of all parts or components, repair or replacement of worn or unserviceable ele-
ments items using original manufacturing tolerances and speciflications, and subsequent reassembly
of the item.
