Appendix B. MAINTENANCE ALLOCATION CHART

TM 55-4920-424-13&P

APPENDIX B

MAINTENANCE ALLOCATION CHART

Section I. INTRODUCTION

MAC or higher headquarters. Identify the cause of

B-1. Maintenance Allocation Chart.

equipment/system

malfunctions

using

applicable

a. This Maintenance Allocation Chart (MAC)

technical manual troubleshooting instructions, Built-In-

assigns maintenance functions in accordance with the

Test Equipment (BITE), installed instruments, or easy to

Three Levels of Maintenance concept for army aircraft.

use Test Measurement and Diagnostic Equipment

These maintenance levels: Aviation Unit Maintenance

(TMDE).

Replace

worn

damaged

(AVUM), Aviation Intermediate Maintenance (AVIM) and

modules/components which do not require complex

Depot Maintenance are depicted on the MAC as:

adjustments or system alignment and which can be

removed/installed with available skills, tools and

AVUM which corresponds to the O code in the

equipment. Perform operational and continuity checks

Repair Parts and Special Tools List (RPSTL).

and make minor repairs. Perform servicing, functional

adjustments, and minor repair/replacement. Evacuate

AVIM which corresponds to the F code in the

unserviceable modules/components and end items

Repair Parts and Special Tools List (RPSTL).

beyond the repair capability of AVUM to the supporting

AVIM.

Depot which corresponds to the D code in the

Repair Parts and Special Tools List (RPSTL).

(b) Less than Company Size Aviation

Units. Aviation elements organic to brigade, group,

b. The maintenance to be performed below depot

battalion headquarters and detachment size units are

and in the field is described as follows:

normally small and have less than ten aircraft assigned.

Maintenance tasks performed by the aircraft crew chief

(1) Aviation Unit Maintenance (AVUM). AVUM

or assigned aircraft repairman will normally be limited to

activities will be staffed and equipped to perform high

preventive maintenance inspections, servicing, spot

frequency "On-Equipment" maintenance tasks required

painting,

spot

drilling,

minor

adjustments,

to retain or return equipment to a serviceable condition.

module/component fault diagnosis and replacement of

The maintenance capability of the AVUM will be

selected modules/components. Repair functions will

governed by the MAC and limited by the amount and

normally be accomplished by the supporting AVIM unit.

complexity of support equipment, facilities required, and

number of spaces and critical skills available. The range

(2) Aviation Intermediate Maintenance (AVIM).

and quantity of authorized spare modules/components

AVIM provides mobile, responsive "One Stop"

will be consistent with the mobility requirements dictated

maintenance support. (Maintenance functions which are

by the air mobility concept. (Assignment of maintenance

not conducive to sustaining air mobility will be assigned

tasks to divisional company size aviation units will

to depot maintenance.) Performs all maintenance

consider the overall maintenance capability of the

functions authorized to be done at AVUM. Repair of

division, the requirement to conserve personnel and

equipment for return to user will emphasize support or

equipment resources and air mobility requirements .)

operational readiness requirements.

Authorized

maintenance includes replacement and repair of

(a) Company Size Aviation Units. Perform

modules/components and end items which can be

those tasks which consist primarily of preventive

accomplished efficiently with available skills, tools, and

maintenance and maintenance repair and replacement

equipment.

Establishes the Direct Exchange (DX)

functions associated with sustaining a high level of

program for AVUM units by repairing selected items for

equipment operational readiness. Perform maintenance

return to stock when such repairs cannot be

inspections and servicing to include daily, intermediate,

accomplished at the AVUM level.

Inspects,

periodic and special inspections as authorized by the

troubleshoots, tests, diagnoses, repairs, adjusts,

B-1