APPENDIX B. MAINTENANCE ALLOCATION CHART

TM 55-4920-415-13&P

APPENDIX B

MAINTENANCE ALLOCATION CHART

SECTION I. INTRODUCTION

B-1. Maintenance Allocation Chart.

(b) Less than Company Size Aviation

a. This Maintenance Allocation Chart (MAC)

Units. Aviation elements organic to brigade, group,

assigns maintenance functions in accordance with the

battalion headquarters and detachment size units are

Three Levels of Maintenance concept for army aircraft.

normally small and have less than ten aircraft assigned.

These maintenance levels: Aviation Unit Maintenance

Maintenance tasks performed by the aircraft crew chief

(AVUM), Aviation Intermediate Maintenance (AVIM) and

or assigned aircraft repairman will normally be limited to

Depot Maintenance are depicted on the MAC as:

preventive maintenance, inspections, servicing, spot

painting,

stop

drilling,

minor

adjustments,

AVUM which corresponds to the 0 code in the

module/component fault diagnosis and replacement of

Repair Parts and Special Tools List (RPSTL).

selected modules/components. Repair functions will

normally be accomplished by the supporting AVIM unit.

AVIM which corresponds to the F code in the

Repair Parts and Special Tools List (RPSTL).

(2) Aviation Intermediate Maintenance (A

VIM). AVIM provides mobile, responsive "One Stop"

DEPOT which corresponds to the D code in the

maintenance support. (Maintenance functions which are

Repair Parts and Special Tools List (RPSTL).

not conducive to sustaining air mobility will be assigned

to depot maintenance).

Performs all maintenance

b. The maintenance to be performed below depot

functions authorized to be done at AVUM. Repair of

and in the field is described as follows:

equipment for return to user will emphasize support or

(1) Aviation Unit Maintenance (AVUM).

operational readiness requirements.

Authorized

AVUM activities will be staffed and equipped to perform

maintenance includes replacement and repair of

high frequency "On-Equipment" maintenance tasks

modules/components and end items which can be

required to retain or return equipment to a serviceable

accomplished efficiently with available skills, tools, and

condition. The maintenance capability of the AVUM will

equipment.

Establishes the Direct Exchange (DX)

be governed by the MAC and limited by the amount and

program for AVUM units by repairing selected items for

complexity of support equipment, facilities required, and

return to stock when such repairs cannot be

number of spaces and critical skills available. The range

accomplished at the AVUM level.

Inspects,

and quantity of authorized space modules/components

troubleshoots, tests, diagnoses, repairs, adjusts,

will be consistent with the mobility requirements dictated

calibrates, and aligns system modules/components.

by the air mobility concept. (Assignment of maintenance

Module/component disassembly and repair will support

tasks to divisional company size aviation units will

the DX program and will normally be limited to tasks

consider the overall maintenance capability of the

requiring cleaning and the replacement of seals, fittings

division, the requirement to conserve personnel and

and items of common hardware.

Unserviceable

equipment resources and air mobility requirements).

repairable modules/ components and end items which

are beyond the capability of AVIM to repair will be

(a) Company Size Aviation Units.

evacuated to Depot Maintenance.

This level will

Perform those tasks which consist primarily of

perform special inspections which exceed AVUM

preventative maintenance and maintenance repair and

capability.

Provides quick response maintenance

replacement functions associated with sustaining a high

support, on-the-job-training, and technical assistance

level of equipment operational readiness.

Perform

through the use of mobile maintenance contact teams.

maintenance inspections and servicing to include daily,

Maintains authorized operational readiness float.

intermediate, periodic and special inspections as

Provides collections and classification services for

authorized by the MAC or higher headquarters. Identify

serviceable/unserviceable material.

Operates a

the cause of equipment/ system malfunctions using

cannibalization activity in accordance with AR 750-50.

applicable technical manual troubleshooting instructions.

(The aircraft maintenance company within the

Built-In-Test Equipment (BITE), installed instruments, or

maintenance battalion of a division will perform AVIM

easy to use Test Measurement and Diagnostic

functions consistent with air mobility requirements and

Equipment (TMDE).

Replace worn or damaged

conservation of personnel and equipment resources.

modules/components or system alignment and which can

Additional intermediate maintenance support will be

be removed/installed with available skills, tools and

provided by the supporting non-divisional AVIM unit).

equipment. Perform operational and continuity checks

and make minor repairs. Perform servicing, functional

B-2. Use of the Maintenance Allocation Chart.

adjustments, and minor repair/replacement. Evacuate

a. The MAC assigns maintenance functions to the

unserviceable modules/components and end items

lowest level of maintenance based on past experience

beyond the repair capability of AVUM to the supporting

and the following consideration:

AVIM.

B-1