OPERATOR'S, UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE
AIR CONDITIONER, HORIZONTAL, COMPACT
INTRODUCTION FOR MAINTENANCE ALLOCATION CHART (MAC)
The Army Maintenance System MAC
This introduction provides a general explanation of all maintenance and repair functions authorized at various maintenance
levels under the standard Army 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:
Unit -- includes two subcolumns, C (operator/crew) and O (unit) maintenance.
Direct Support -- includes an F subcolumn.
General Support -- includes an H subcolumn.
Depot -- includes a D subcolumn.
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 from the MAC.
The remarks (immediately following the tools and test equipment requirements) contain supplemental instructions and
explanatory notes for a particular maintenance function.
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 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, che mical fluids, or gases.
This includes scheduled exercising and purging of 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 to 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