TM 9-4120-402-14
APPENDIX B
MAINTENANCE ALLOCATION CHART
Section I INTRODUCTION
B-1. GENERAL.
a. This section provides a general explanation of all maintenance and repair functions authorized at various
maintenance categories.
b. The Maintenance Allocation Chart (MAC) in Section II designates overall 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 will be consistent with the capacities and capabilities of the designated maintenance categories.
c. Section III lists the tools and test equipment (both special tools and common tool sets) required for each
maintenance function as referenced from Section II.
d. Section IV contains supplemental instructions and explanatory notes for a particular maintenance function.
B-2. MAINTENANCE FUNCTIONS.
Maintenance functions will be limited to and defined as follows:
a. 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).
b. Test. To verify serviceability by measuring the mechanical or electrical characteristics of an item and
comparing those characteristics with prescribed standards.
c. Service. Operations required periodically to keep an item in proper operating condition, i.e., to clean
(decontaminate), to preserve, to drain, to paint, or to replenish fuel, lubricants, chemical fluids, or gases.
d. Adjust. To maintain, within prescribed limits, by bringing into proper or exact position, or by setting the
operating characteristics to specified parameters.
e. Aline. To adjust specified variable elements of an item to bring about optimum or desired performance.
f. Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or 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.
g. 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.
h. Replace. To remove an unserviceable item and install a serviceable counterpart in its place. "Replace" is
authorized by the MAC and is shown as the 3d position code of the SMR code.
B-1
