TM 9-4520-251-14
Appendix B. MAINTENANCE ALLOCATION CHART
Section I. INTRODUCTION
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GENERAL.
a.
This section provides a general explanation of all maintenance and repair functions authorized at
various maintenance categories.
b. The Maintenance Allocation Chart (MAC) in Section II designates overall authority and responsibil-
ity for the performance of maintenance functions on the identified end item or component, The ap-
plication of the maintenance functions to the end item or component will be consistent with the capa-
cities and capabilities of the designated maintenance categories.
c.
Section Ill lists the tools and test equipment (both special tools and common tool sets) required for
each maintenance function as referenced from Section Il.
d. Section IV contains supplemental instructions and explanatory notes for a particular maintenance
function.
B-2 MAINTENANCE FUNCTIONS.
Maintenance functions will be limited to and defined as follows:
a.
Inspect. To determine the serviceability of an item by comparing its physical, mechanical and/or
electrical characteristics with established standards through examination (e.g., by sight, sound, or
feel).
b. Test. To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical char-
acteristics of an item and comparing those characteristics with prescribed standards.
c.
Service. Operations required periodically to keep an item in proper operating condition, i.e., to clean
(includes decontaminate when required), to preserve, to drain, to paint, or to replenish fuel, lubri-
cants, chemical fluids, or gases.
d. Adjust. To maintain or regulate, within prescribed limits, by bringing into proper or exact position,
or by setting the operating characteristics to specified parameters.
e. Align. To adjust specified variable elements of an item to bring about optimum or desired perfor-
mance.
f.
Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test,
measuring, and diagnostic equipments used in precision measurement. 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.
g. Remove/lnstall. To remove and install the same item when required to perform service or other
maintenance functions. Install may be the act of emplacing, seating, or fixing into position a spare,
repair part, or module (component or assembly) in a manner to allow the proper functioning of an
equipment or system.
h. Replace. To remove an unserviceable item and install a serviceable counterpart in its place. “Re-
place” is authorized by the MAC and is shown as the third position code of the SMR code.
i.
Repair. The application of maintenance services1, including fault location/troubleshooting2, remov-
al/installation, and disassembly/assembly3 procedures, 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), end item, or system.
1 Services – inspect, test, service, adjust, align, calibrate, and/or replace.
2 Fault locate/troubleshoot – the process of 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 – encompasses the step–by–step taking apart (or breakdown) of a spare/functional group coded
item to the level of its least componency identified as maintenance significant (i.e., assigned an SMR code) for the cate-
gory or maintenance under consideration.
4 Actions – welding, grinding, riveting, straightening, facing, remachinery, and/or resurfacing.
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