Appendix A. MAINTENANCE ALLOCATION CHART

TM 55-4920-431-13

APPENDIX A

MAINTENANCE ALLOCATION CHART

Section I. INTRODUCTION

A-1. Maintenance Allocation Chart.

a. This Maintenance Allocation Chart (MAC) assigns maintenance functions in accor-

dance with the Three Levels of Maintenance concept for army aircraft. These maintenance

levels: Aviation Unit Maintenance (AVUM), Aviation Intermediate Maintenance (AVIM) and

Depot Maintenance are depicted on the MAC as:

AVUM which corresponds to the O code in the Repair Parts and Special

Tools List (RPSTL).

AVIM which corresponds to the F code in the Repair Parts and Special

Tools List (RPSTL).

DEPOT which corresponds to the D code in the Repair Parts and Special

Tools List (RPSTL).

b. The maintenance to be performed below depot and in the field is described as

follows:

1. Aviation Unit Maintenance (AVUM). AVUM activities will be staffed and

equipped to perform high frequency "On-Equipment" maintenance tasks required to retain

or return equipment to a serviceable condition. The maintenance capability of the AVUM

will be governed by the MAC and limited by the amount and complexity of support equipment,

facilities required, and number of spaces and critical skills available. The range and

quantity of authorized spare modules/components will be consistent with the mobility re-

quirements dictated by the air mobility concept. (Assignment of maintenance tasks to

divisional company size aviation units will consider the overall maintenance capability of

the division, the requirement to conserve personnel and equipment resources and air

mobility requirements).

(a) Company Size Aviation Units. Perform those tasks which consist pri-

marily of preventive maintenance and maintenance repair and replacement functions asso-

ciated with sustaining a high level of equipment operational readiness. Perform mainte-

nance inspections and servicing to include daily, intermediate, periodic and special

inspections as authorized by the MAC or higher headquarters. Identify the cause of

equipment system malfunctions using applicable technical manual troubleshooting instruc-

tions. Built-In-Test Equipment (BITE), installed instruments, or easy to use Test

Measurement and Diagnostic Equipment (TMDE). Replace worn or damaged modules/

components which do not require complex adjustments or system alignments and which

can be removed/installed with available skills, tools and equipment. Perform operational

and continuity checks and make minor repairs. Perform servicing, functional adjustments,

and minor repair/replacement. Evacuate unserviceable modules/components and end

items beyond the repair capability of AVUM to the supporting AVIM.

(b) Less than Company Size Aviation Units. Aviation elements organic to

brigade, group, battalion headquarters and detachment size units are normally small and

A-1