i. Repair. To restore an item to serviceable condition
through correction of a specific failure or unserviceable
condition. This includes. but is not limited to, inspec-
tion. cleaning. preserving. adjusting. replacing. welding,
riveting, and strengthening.
j. Overhaul To restore an item to a completely ser-
viceable condition as prescribed by maintenance ser-
viceability standards prepared and published for the
specific item to be overhauled.
k. Rebuild To restore an item to a standard as nearly
as possible to the original or new condition in ap-
pearance, performance. and life expectancy. This is ac-
complished through the maintenance technique of com-
plete disassembly of the item, inspection of all parta or
components, repair or replacement of worn or unser-
viceable elements (items) using original manufacturing
tolerances and specifications, and subsequent
reassembly of the item.
B-4. Functional Groups Standard functional group
inge are not considered feasible for aviation ground sup-
port equipment due to variation and complexity.
Therefore, variations to functional groupings may oC-
cur.
B-5. Maintenance Categories and Work Times. The
maintenance categories (levels) AVUM, AVIM, and
DEPOT are listed on the Maintenance Allocation Chart
W.s,buwlwnc rmntt~ 0fEice;19S9-6w031/53031
TM 55-4920-402-13&P
with individual columns that indicate the work times for
maintenance functions at each maintenance level. Work
time presentations such as 0.1 indicate the average time
it requires a maintenance level to perform a specified
maintenance function. If a work time has not been
established, the columnar presentation shall indicate
Maintenance levels higher than the level of
maintenance indicated are authorized to perform the in-
dicated function.
B-6. Tools and Test Equipment (Section III). Common
tool sets (not individual tools), special tools, test and
support equipment required to perform maintenance
functions are listed alphabetically with a reference
number to permit cross-referencing to column 5 in the
MAC. In addition, the maintenance category authorized
to use the device is listed along with the item National
Stock Number (NSN) and, if applicable, the tool number
to aid in identifying the tool/device.
B-7. Remarks (Section IV). Remarks contained in col-
umn 6, with an alphabetical code and other columnar
notea identified by a number in parentheses, are listed to
provide a ready reference to the definition of the
remark/note.
Change 5
B-3
