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TM 5-2420-231-23-3
FIELD MAINTENANCE
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MAINTENANCE ALLOCATION CHART (MAC) INTRODUCTION
0373
THE ARMY MAINTENANCE SYSTEM MAC
000373
This introduction provides a general explanation of all maintenance and repair functions authorized at the two
maintenance levels under the Two-Level Maintenance System concept.
This MAC (immediately following the introduction) designates overall authority and responsibility for the
performance of maintenance functions on the identified end item or component. The application of the
maintenance functions to the end item or component shall be consistent with the capacities and capabilities of the
designated maintenance levels, which are shown on the MAC in column (4) as:
Field (includes two subcolumns):
C - Crew
F - Maintainer
Sustainment (includes two subcolumns):
H - Below Depot
D - Depot
The maintenance to be performed at field and sustainment levels is described as follows:
1. Crew maintenance. The responsibility of a using organization to perform maintenance on its assigned
equipment. It normally consists of inspecting, servicing, lubricating, adjusting, and replacing parts, minor
assemblies, and subassemblies. The replace function for this level of maintenance is indicated by the letter "C"
in the third position of the SMR code. A "C" appearing in the fourth position of the SMR code indicates
complete repair is possible at the crew maintenance level.
2. Maintainer maintenance. Maintenance accomplished on a component, accessory, assembly, subassembly,
plug-in unit, or other portion either on the system or after it is removed. The replace function for this level of
maintenance is indicated by the letter "F" appearing in the third position of the SMR code. An "F" appearing in
the fourth position of the SMR code indicates complete repair is possible at the field maintenance level. Items
are returned to the user after maintenance is performed at this level.
3. Below depot sustainment. Maintenance accomplished on a component, accessory, assembly, subassembly,
plug-in unit, or other portion either on the system or after it is removed. The replace function for this level of
maintenance is indicated by the letter "H" appearing in the third position of the SMR code. An "H' appearing in
the fourth position of the SMR code indicates complete repair is possible at the below depot sustainment
maintenance level. Items are returned to the supply system after maintenance is performed at this level.
4. Depot sustainment. Maintenance accomplished on a component, accessory, assembly, subassembly, plug-in
unit, or other portion either on the system or after it is removed. The replace function for this level of
maintenance is indicated by the letter "D" or "K" appearing in the third position of the SMR code. Depot
sustainment maintenance can be performed by either depot personnel or contractor personnel. A "D" or "K"
appearing in the fourth position of the SMR code indicates complete repair is possible at the depot sustainment
maintenance level. Items are returned to the supply systems after maintenance is performed at this level.
The tools and test equipment requirements table (immediately following the MAC) lists the tools and test
equipment (both special tools and common tool sets) required for each maintenance function as referenced from
the MAC.
The remarks table (immediately following the tools and test equipment requirements) contains supplemental
instructions and explanatory notes for a particular maintenance function.
0373-1
