Definitions.

TM 55-4920-415-13&P

(1) Skills available.

d. Adjust. To rectify to the extent necessary to

(2) Time required.

bring into proper operating range.

(3) Tools and test equipment required and/or

e. Aline. To adjust specified variable elements of

available.

an item to bring to optimum performance.

b. Only the lowest level of maintenance authorized

f. Calibrate. To determine the corrections to be

to perform a maintenance function is indicated. If the

made in the readings of instruments or test equipment

lowest level of maintenance cannot perform all tasks of

used in precise measurement.

Consists of the

any single maintenance function (e.g., test, repair), then

comparison of two instruments, one of which is a certified

the higher maintenance level(s) that can accomplish

standard of known accuracy, to detect and adjust any

additional tasks will also be indicated.

discrepancy in the accuracy of the instrument or test

equipment being compared with the certified standard.

c. A maintenance function assigned to a

maintenance level will automatically be authorized to be

g. Install. To set up for use in an operational

performed at any higher maintenance level.

environment such as an emplacement, site or vehicle.

d. A maintenance function that cannot be

h. Replace. To replace unserviceable items with

performed at the assigned level of maintenance for any

serviceable assemblies, subassemblies or parts.

reason may be evacuated to the next higher

i. Repair.

To restore an item to serviceable

maintenance organization. Higher maintenance levels

condition through correction of a specific failure or

will perform the maintenance functions of lower

unserviceable condition. This includes, but is not limited

maintenance levels when required or directed by the

to, inspection, cleaning, preserving, adjusting, replacing,

appropriate commander.

welding, riveting, and strengthening.

e. The assignment of a maintenance function will

j. Overhaul. To restore an item to a completely

not be construed as authorization to carry the associated

serviceable condition as prescribed by maintenance

repair parts in stock. Authority to requisition, stock, or

serviceability standards prepared and published for the

otherwise secure necessary repair parts will be as

specific item to be overhauled.

specified in the repair parts and special tools list

appendix.

k. Rebuild. To restore an item to a standard as

nearly as possible to the original or new condition in

f. Normally there will be no deviation from the

appearance, performance, and life expectancy. This is

assigned level of maintenance. In cases of operational

accomplished through the maintenance technique of

necessity, maintenance functions assigned to a

complete disassembly of the item, inspection of all parts

maintenance level may, on a one-time basis and at the

or components, repair or replacement of worn or

request of the lower maintenance level, be specifically

unserviceable

elements

(items)

using

original

authorized by the maintenance officer of the level of

manufacturing tolerances and specifications, and

maintenance to which the function is assigned. The

subsequent reassembly of the item.

special tools, equipment, etc. required by the lower level

of maintenance to perform this function will be furnished

B-4. Functional Groups.

by the maintenance level to which the function is

Standard functional groupings are not considered

assigned. This transfer of a maintenance function to a

feasible for aviation ground support equipment due to

lower maintenance level does not relieve the higher

variation and complexity.

Therefore, variations to

maintenance level of the responsibility of the function.

functional groupings may occur.

The higher level of maintenance will provide technical

supervision and inspection of the function being

B-5. Maintenance Categories and Work Times.

performed at the lower level.

The maintenance categories (levels) AVUM, AVIM,

g. Organizational through depot maintenance of the

and DEPOT are listed on the Maintenance Allocation

US Army Electronics Command equipment will be

Chart with individual columns that indicate the work times

performed by designated US Army Electronics Command

for maintenance functions at each maintenance level.

personnel.

Work time presentations such as 0.1 indicate the average

time it requires a maintenance level to perform a

h. Changes to the MAC will be based on continuing

specified maintenance function. If a work time has not

evaluation and analysis by responsible technical

been established, the columnar presentation shall

personnel and on reports received from field activities.

indicate "- -". Maintenance levels higher than the level of

B-3. Definitions.

maintenance indicated are authorized to perform the

indicated function.

a. Inspect. To determine serviceability of an item

B-6. Tools and Test Equipment (Section III).

by comparing its physical, mechanical and electrical

characteristics with established standards.

Common tool sets (not individual tools), special tools,

test and support equipment required to perform

b. Test. To verify serviceability and detect incipient

maintenance functions are listed alphabetically with a

failure by measuring the mechanical or electrical

reference number to permit cross-referencing to column

characteristics of an item and comparing those

5 in the MAC. In addition, the maintenance category

characteristics with prescribed standards.

authorized to use the devise is listed along with the item

c. Service. To clean, to preserve, to charge, and to

National Stock Number (NSN) and, if applicable, the tool

add fuel, lubricants, cooling agents and air.

number to aid in identifying the tool/device.

B-2