MAINTENANCE ALLOCATION CHART (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.
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
gagings 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
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
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