TM 5-2420-224-20-2
when the engine is listed separately in the MAC. The symbol designations for the various maintenance
categories remain as follows:
C —
O —
F —
H —
D —
Operator/Crew
Unit Maintenance
Direct Support Maintenance
General Support Maintenance
Depot Maintenance
Column 5, Tools and Equipment. Column 5 specifies, by code, those common tool sets (not individual
tools) and special tools, test, and support equipment required to perform the designated functions.
Column 6, Remarks. Column 6 references any amplifying remarks.
MANTENANCE
FUNCTIONS
DEFINED
Inspect. To closely and critically examine (e.g., sight, sound, or feel) an item to detect errors, flaws,
wear, etc., and to determine its condition and serviceability by comparing its physical mechanical/electrical
. .
characteristics within established standards.
Test. To verify sewiceability and detect incipient failure by
characteristics of an item and comparing those characteristics
Service. Operations required periodically to keep an item in
.
-
.
.
measuring the mechanical or electrical
with prescribed standards.
proper operating condition; i.e., to clean
(decontaminate), to preserve, to drain, to paint, or to replenish fuel, lubricants, hydraulic fluids, or compressed
air supplies.
Adjust. To maintain, within prescribed limits, by bringing into proper or exact position, or by setting
the operating characteristics to specified parameters.
Aline. To adjust specified variable elements of an item to bring about optimum or desired performance,
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 comparison 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.
Install. The act of emplacing, seating, or fixing into position an item, part, or module (component
or assembly) in a manner to allow the proper functioning of an equipment or system.
Replace. The act of substituting a serviceable like type part, subassembly, or module (component
or assembly) for an unserviceable counterpart.
Repair. The application of maintenance services (inspect, test, service, adjust, aline, calibrate, or
replace) or other maintenance actions (weiding, grinding, riveting, straightening, facing, remachining, or
resurfacing) to 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.
Overhaul. That maintenance effort (service/action) necessary to restore an item to a completely
serviceable/operational condition as prescribed by maintenance standards (i.e., DMWR) 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.
B-2
