TM 1-4940-355-12&P
SHOP EQUIPMENT CONTACT MAINTENANCE (SECM)
MAINTENANCE ALLOCATION CHART (MAC)
INTRODUCTION
AVIATION MAINTENANCE ALLOCATION CHART
This 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 in the MAC as:
AVUM - corresponds to an "O" code in the Repair Parts and Special Tools List (RPSTL).
AVIM - corresponds to an "F" code in the RPSTL.
DEPOT - corresponds to a "D" code in the RPSTL.
The maintenance to be performed below 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 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.)
1. Company Size Aviation Units. Perform those tasks which consist primarily of preventive 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 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 alignment. 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 support AVIM.
2. Less than Company Size Aviation Units. Aviation elements organic to brigade, group, battalion headquarters,
and detachment size units are normally small and have less than 10 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 preventive 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).
1. Provides mobile, responsive "one-stop" maintenance support. (Maintenance functions which are not
conducive to sustaining air mobility will be assigned to depot maintenance.)
0024 00-1
