ARMY TM 10-1670-279-23&P
AIR FORCE T.O. 13C5-27-2
NAVY NAVAIR 131-28
B-2. Maintenance Functions (cont).
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.
i. Repair. The application of maintenance services, including fault location/troubleshooting, removal installation, and
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.
j. Overhaul. That maintenance effort (service/action) prescribed to restore an item to a completely
serviceable/operational condition as required by maintenance standards in appropriate technical publications (i.e.,
DMWR). Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul does not normally
return an item to like new condition.
k. Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to a like new
condition in accordance with original manufacturing standards. Rebuild is the highest degree of materiel maintenance
applied to Army equipment. The rebuild operation includes the act of returning to zero those age measurements
(hours/miles, etc.) considered in classifying Army equipment/components.
B-3. Explanation of Columns in the MAC, Section II.
a. Column 1, Group Number. Column 1 lists functional group code numbers the purpose of which is to identify
maintenance significant components, assemblies, subassemblies, and modules with the next higher assembly. End item
group number shall be "00".
b. Column 2, Component/Assembly. Column 2 contains the names of components, assemblies, subassemblies, and
modules for which maintenance is authorized.
c. Column 3, Maintenance Function. Column 3 lists the functions to be performed on the item listed in Column 2.
(For detailed explanation of these functions, see paragraph B-2).
d. Column 4, Maintenance Level. Column 4 specifies, by the listing of work time figure in the appropriate
subcolumn(s), the level of maintenance authorized to perform the function listed in Column 3. This figure represents the
active time required to perform that maintenance function at the indicated level of maintenance. If the number or
complexity of the tasks within the listed maintenance function vary at different maintenance levels, appropriate work time
figures will be shown for each level. The work time figure represents the average time required to restore an item
(assembly, subassembly, component, module, end item, or system) to a serviceable condition under typical field
operating conditions. This time includes preparation time (including any necessary disassembly/assembly time),
troubleshooting/fault location time, and quality assurance/quality control time in addition to the time required to perform
the specific tasks identified for the maintenance functions authorized in the maintenance allocation chart. The symbol
designations for the various maintenance levels are as follows:
C - Operator or crew
O - Unit Maintenance
F - Intermediate Direct Support Maintenance
H - Intermediate General Support Maintenance
D - Depot Maintenance