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.
Remove/Install. To remove and install the same item when required to perform service or
other maintenance functions. Install may be the act of placing, 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.
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.
The following definitions are applicable to the "Repair" maintenance
Services. Inspect, test, service, adjust, align, calibrate, and/or replace.
Fault location/troubleshooting. The process of investigating and detecting
the cause of equipment malfunctioning: the act of isolating a fault within a
system or Unit Under Test (UUT).
Disassembly/assembly. The step-by-step breakdown (taking apart) of a
spare/functional group coded item to the level of its least component,
which is assigned an SMR code for the level of maintenance under
consideration, i.e., identified as maintenance significant.
Actions. Welding, grinding, riveting, straightening, facing, machining,
Repair. The application of maintenance services, including fault location/troubleshooting,
removal/installation, disassembly/assembly procedures, and maintenance actions to identify
problems 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
Overhaul. The maintenance effort (service/action) prescribed to restore an item to a
completely serviceable/operational condition as required by maintenance standards in
appropriate technical publications. Overhaul is normally the highest degree of maintenance
performed by the Army. Overhaul does not normally return an item to like new condition.
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 material maintenance applied to Army equipment. The
rebuild operation includes the act of returning to zero those age measurements (e.g.,
hours/miles) considered in classifying Army equipment/components.
Explanation of Columns in the MAC
Column 1, Group Number. Column 1 lists FGC numbers, the purpose of which is to identify
maintenance significant components, assemblies, subassemblies, and modules with the Next
Higher Assembly (NHA).
Appendix B-2 Change 1