TM 1-5855-265-20
B-1
APPENDIX B
MAINTENANCE ALLOCATION CHART
Section I. INTRODUCTION
B-1. MAINTENANCE ALLOCATION CHART
a. This Maintenance Allocation Chart (MAC) assigns maintenance functions in accordance with
the Three Levels of Maintenance concept for Army aviation. These maintenance levels (categories)
Aviation Unit Maintenance (AVUM), Aviation Intermediate Maintenance (AVIM), and Depot Maintenance
are depicted on the MAC as:
AVUM, which corresponds to an 0 Code in the Repair Parts and Special Tools List (RPSTL)
AVIM, which corresponds to an F Code in the Repair Parts and Special Tools List (RPSTL)
DEPOT, which corresponds to a 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) activities will be staffed and equipped to perform high
frequency "On-Aircraft" maintenance tasks required to retain or return aircraft systems to a serviceable
condition. The maintenance capability of the AVUM will be governed by the Maintenance Allocation
Chart (MAC) and limited by the amount and complexity of ground support equipment (GSE), facilities
required, authorized manning strength, and critical skills available. The range and quantity of authorized
spare modules/components will be consistent with the mobility requirements dictated by the air mobility
concept. (Assignments 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 primarily of
preventive maintenance repair and replacement functions associated with sustaining a high level of
aircraft operational readiness. Perform maintenance inspections and servicing to include preflight, daily,
intermediate, periodic (or phased), and special inspections as authorized by the MAC or higher
headquarters. Identify the cause of equipment/system malfunctions using applicable technical manual
troubleshooting instructions, built-in test equipment (BITE), installed aircraft instruments, or test,
measurement, and diagnostic equipment (TMDE). Replace worn or damaged modules/components that
do not require complex adjustments or system alinement and which can be removed/installed with
available skills, tools, and ground support equipment. Perform operational and continuity checks and
make minor repairs to the electrical system. Inspect, service, and make operational, capacity, and
pressure checks to hydraulic systems. Perform servicing, functional adjustments, and minor repair/
replacement to the flight control, propulsion, power train, and fuel systems. Accomplish air frame repair
that does not require extensive disassembly, jigging, or alinement. The manufacture of air frame parts
will be limited to those items which can be fabricated with tools and equipment found in current airmobile
tool and shop sets. Evacuate unserviceable modules/components and end items beyond the repair
capability of AVUM to the supporting AVIM.
