TM 1-1520-238-23
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 Aviation
Maintenance concept for Army aviation. These maintenance levels, Aviation Unit Maintenance (AVUM), Aviation
Intermediate Maintenance (AVIM), and Depot Maintenance are depicted on the MAC as:
(1) AVUM – corresponds to an O code in the Repair Parts and Special Tools List (RPSTL).
(2) AVIM – corresponds to an F code in the Repair Parts and Special Tools List (RPSTL).
(3) DEPOT – 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 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 mainte-
nance and maintenance repair and replacement functions associated with sustaining a high level of aircraft opera-
tional 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 airframe repair that does not require extensive disassembly,
jigging, or alinement. The manufacture of airframe parts will be limited to those items which can be fabricated with
tools and equipment found in current air mobile tool and shop sets. Evacuate unserviceable modules/components
and end items beyond the repair capability of AVUM to the supporting AVIM.
