AVIATION UNIT MAINTENANCE (AVUM) AND
AVIATION INTERMEDIATE MAINTENANCE (AVIM) CONCEPT
a. This appendix explains the maintenance functions of the Three Levels of Maintenance concept for Army aircraft.
These maintenance levels, Aviation Unit Maintenance (AVUM); Aviation Intermediate Maintenance (AVIM); and Depot
Maintenance, are shown in the third, fourth, and fifth positions of the SMR codes of this RPSTL as:
b. The maintenance to be performed below depot level is described as follows:
(1) Aviation Unit Maintenance (AVUM). AVUM activities will be staffed and equipped to perform high
frequency "On-Aircraft" maintenance tasks required to maintain a level of aircraft readiness. 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, and number of personnel and critical skills available. The range and quantity
of authorized spare modules/components will be consistent with the air mobility concept.
(a) Company Size Aviation Units. These units will perform those tasks which consist primarily of
preventive maintenance and 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, and special inspections as authorized by the MAC. Identify the cause of equipment/system malfunctions using
applicable technical manual troubleshooting instructions, builtin-test equipment (BITE), installed aircraft instruments, or
easy to use/interpret diagnostic/fault isolation devices (TMDE). Replace worn or damaged modules/ components which
do not require complex adjustments or system alignment and which can be removed/installed with available skills, tools,
and equipment. Perform operational and continuity checks and make minor repairs to the flight control, propulsion,
power train, and fuel systems. Accomplish air frame repair which does not require 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 supporting AVIM. (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
(b) Less Than Company Size Aviation Units. Aviation elements organic to brigade, group, battalion
headquarters, and detachment size units are normally small and have fewer 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 preventive maintenance, inspections, servicing, spot painting, stop drilling,
application of nonstress patches, minor adjustments, module/component fault diagnosis and replacement of selected
modules/components. Repair functions will normally be accomplished by the supporting AVIM unit.
(2) Aviation Intermediate Maintenance (AVIM). AVIM provides mobile, maintenance support to AV AVUM.
(Maintenance functions which are not conducive to sustaining air mobility will be assigned to depot maintenance.)
Performs all maintenance functions authorized to be done at AVUM. Repair of equipment for return to user will
emphasize support or operational readiness requirements. Authorized maintenance includes replacement and repair of
modules/components and end items which can be accomplished efficiently with available skills, tools, and equipment.
Establishes the Direct Exchange (DX) program for AVUM units by repairing selected items for return to stock (when such
repairs cannot be accomplished at the AVUM level). Inspects, troubleshoots, tests, diagnoses, repairs, adjusts,