TM 1-1740-221-13&P&P
FIELD MAINTENANCE
MAINTENANCE ALLOCATION CHART (MAC) INTRODUCTION
The Army Maintenance System MAC
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 identiied 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 sub-columns, Crew (C) and Maintainer (F)
Sustainment
includes two sub-columns, Below Depot (H) and Depot (D).
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 ield 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.
Maintenance Functions
Maintenance functions will be limited to and deined as follows:
1. 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). This includes
scheduled inspection, gauging and evaluation of cannon tubes.
2. Test. To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical characteristics of
an item and comparing those characteristics with prescribed standards on a scheduled basis, i.e., load testing of lift
devices and hydrostatic testing of pressure hoses.
3. Service. Operations required periodically to keep an item in proper operating condition; e.g., to clean (includes
decontaminate, when required), to preserve, to drain, to paint, or to replenish fuel, lubricants, chemical luids,
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