TM 9-2330-213-14&P
MAINTENANCE ALLOCATION CHART (MAC)
Section 1: INTRODUCTION
B-1. General
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.
The 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, Unit (C (operator/crew) and O (unit) maintenance) and
Direct Support (F) maintenance
Sustainment -- includes two subcolumns, general support (H) and depot (D)
The tools and test equipment requirements (immediately following the MAC) list the tools and test
equipment (both special tools and common tool sets) required for each maintenance function as referenced
for the MAC).
The remarks (immediately following the tools and test equipment requirements) contain supplemental
instructions and explanatory notes for a particular maintenance function.
B-2. Maintenance Functions
Maintenance functions are limited to and defined 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 and 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 fluids, or gases. This includes scheduled exercising and purging or recoil mechanisms.
4. Adjust. To maintain or regulate, within prescribed limits, by bringing into proper position, or by setting
the operating characteristics to specified parameters.
5.
Align. To adjust specified variable elements of an item to bring about optimum or desired
performance.
6. Calibrate. To determine and cause corrections to be made or be adjusted on instruments of test,
measuring, and diagnostic equipment 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.
7. Remove/Install. 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.
8. Replace. To remove an unserviceable item and install a serviceable counterpart in its place. "Replace"
is authorized by the MAC and assigned maintenance level is shown as the third position code of the
Source, Maintenance, and Recoverability (SMR) code.
9. Repair. The application of maintenance services, including fault location/troubleshooting,
removal/installation, disassembly/assembly procedures, and maintenance actions 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.