MAINTENANCE ALLOCATION CHART
The Army Maintenance System MAC
This introduction provides a general explanation of all maintenance and repair functions authorized at various
maintenance levels under the standard Army Maintenance System concept.
The Maintenance Allocation Chart (MAC) designates overall authority and responsibility for the performance of
maintenance functions on the identified end item or component. The application of the maintenance functions
Aviation Unit Maintenance (AVUM), Aviation Intermediate Maintenance (AVIM), and Depot Maintenanceto the end
item or component will be consistent with the capacities and capabilities of the designated maintenance levels, which
are shown on the MAC in column (4) as:
AVUM corresponds to an O code in the Repair Parts and Special Tools List (RPSTL).
AVIM corresponds to F code in the RPSTL.
DEPOT corresponds to a D code in the RPSTL.
The maintenance to be performed at the depot and in the field is described as follows:
Aviation Unit Maintenance (AVUM) - AVUM activities will be staffed and equipped to perform high frequency On-
Aircraft 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 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-sized aviation units will consider the overall
maintenance capability of the division, the requirement to conserve personnel and equipment resources, and air
Company-Sized Aviation Units. Perform those tasks that consist primarily of preventative maintenance
and 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 alignment and which can be removed/installed with
available skills, tools, and ground support equipment. Perform operational and continuity checks and
makes 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 alignment. The manufacture of airframe
parts will be limited to those items that 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 support AVIM.
Less than Company-Sized Aviation Units. Aviation elements organic to brigade, group, battalion
headquarters, and detachment-sized units are normally small and have less than ten aircraft assigned.
Maintenance tasks performed by these units will be those which can be accomplished by the aircraft crew
chief or assigned aircraft repairman and will normally be limited to preventative maintenance, inspections,
servicing, spot painting, module/component fault diagnosis, and replacement of selected
modules/components. Repair functions will normally be accomplished by the support AVIM unit.
Aviation Intermediate Maintenance (AVIM) United States Army TMDE Support Group (USATSG) provides AVIM
support. Authorized maintenance includes replacement and repair of modules/components and end items that can
be accomplished efficiently with available skills, tools, and equipment. USATSG inspects, troubleshoots, tests,
diagnoses, repairs, adjusts, calibrates, and aligns system modules and components.
Provides mobile, responsive one-stop maintenance support. (Maintenance functions that are not
conducive to sustaining air mobility will be assigned to depot maintenance.)