TO 31S9-4-38-1 Chg 4
MAINTENANCE ALLOCATION CHART
Section I. INTRODUCTION
item and comparing those characteristics with prescribed
a. This section provides a general explanation of all
C Service: Operations required periodically) to keep an item in proper
maintenance and repair functions authorized at various
operating conditions, i.e., to clean, to preserve, to drain, to
paint, or to replenish fuel, lubricants, hydraulic fluids, or com-
pressed air supplies.
performance of maintenance functions on the identified end
D Adjust: To maintain within prescribed limits, by bringing into
proper or exact position, or by setting the operating
item or component and the work measurement time required
characteristics to specified parameters.
to perform the functions by the designated maintenance level.
E Aline: To adjust specified variable elements of an item to bring
The implementation of the maintenance functions upon the
about optimum or desired performance.
end item or component will be consistent with the assigned
F Calibrate: To determine and cause corrections to be made or to be
adjusted on instruments or test measuring and diagnostic
c. Section III Special Tools and Test Equipment
equipments used in precision measurement. Consists of com-
parisons of two instruments, one of which is a certified stand-
Required for Each Maintenance Function Referenced From
ard of known accuracy, to detect and adjust any discrepancy in
Section II (Not Applicable).
the accuracy of the instrument being compared.
d. Section IV contains supplemental instructions or
G Install: The act of emplacing, seating, or fixing into position an
explanatory notes for a particular maintenance function (Not
item, part, or module (component or assembly) in a manner to
allow the proper functioning of an equipment or system.
H Replace: The act of substituting a serviceable like type part,
C -2. Explanation of Columns in Section II
subassembly, or module (component or assembly) for an un-
a. Column (1), Group Number. A number is assigned to each
group in a top down breakdown sequence. The applicable
I Repair: The application of maintenance services (inspect, test,
groups are listed on the MAC in disassembly sequence
service, adjust, align, calibrate, or replace) or other mainte-
beginning with the first group removed.
nance actions (welding, grinding riveting, straightening, fac-
ing, remachining or resurfacing)to restore serviceability to an
b. Column (2), Assembly Group. This column contains a
item by correcting specific damage, fault, malfunction, or
brief description of the components of each numerical group.
failure in a part, subassembly, module (component or
assembly), end item, or system.
J Overhaul: That maintenance effort (service/action) necessary' to
c. Column (3), Maintenance Functions. This column lists the
restore an item to a completely serviceable/operational condi-
various maintenance functions (A through K). The lowest
tion as prescribed by maintenance standards (i.e., DMWR) in
maintenance level authorized to perform these functions is
appropriate technical publication. Overhaul is normally), the
indicated by a symbol in the appropriate column. Work
highest degree of maintenance performed b)' the Army.
measurement time standards (the active repair time required
Overhaul does not nomally return an item to like new condi-
to perform the maintenance function) are shown directly below
the symbol identifying the maintenance level. The symbol
K Rebuild: Consists of those services/actions necessary for the
restoration of unserviceable equipment to a like new condition
designations for the various maintenance levels are as
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 measurement (hours/miles, etc.) considered
Operator or crew.
in classifying Army equipment/components.
d. Column (4), Tools and Equipment. This column is
Direct support maintenance.
provided for referencing by code the special tools and test
General support maintenance.
equipment (sec III) required to perform the maintenance
functions (sec II).
The maintenance functions are defined as follows:
e. Column (5), Remarks. This column is provided for
A Inspect: To determine serviceability of an item by comparing its
physical, mechanical, and electrical characteristics with estab-
referencing by code the remarks (sec IV) pertinent to the
lished standards through examination.
B Test: To verify serviceability and detect incipient failure by'
measuring the mechancal or electrical characteristics of an
Change 4 C-1