TM 55-4920-399-13&P
APPENDIX B
MAINTENANCE ALLOCATION CHART
Section I. INTRODUCTION
malfunctions using applicable technical manual
B-1. Maintenance Allocation Chart.
troubleshooting instructions, Built-In-Test Equip-
a. This Maintenance Allocation Chart (MAC)
ment (BITE), installed instruments, or easy to use
assigns maintenance functions in accordance with
Test Measurement and Diagnostic Equipment
the Three Levels of Maintenance concept for army
(TMDE). Replace worn or damaged modules/com-
aircraft. These maintenance levels: Aviation Unit
ponents which do not require complex adjustments
M a i n t e n a n c e (AVUM), Aviation Intermediate
or system alignment and which can be remov-
Maintenance (AVIM) and Depot Maintenance are
ed/installed with available skills, tools and equip-
depicted on the MAC as:
AVUM which corresponds to the O code in the
and make minor repairs. Perform servicing, func-
tional adjustments, and minor repair/replacement.
Repair Parts and Special Tools List (RPSTL).
Evacuate unserviceable modules/components and
AVIM which corresponds to the F code in the
end items beyond the repair capability of AVUM
Repair Parts and Special Tools List (RPSTL).
to the supporting AVIM.
Depot which corresponds to the D code in the
(b) Less than Company Size Aviation Units.
Repair Parts and Special Tools List (RPSTL).
Aviation elements organic to brigade, group, bat-
b. The maintenance to be performed below depot
talion headquarters and detachment size "units are
and in the field is described as follows:
normally small and have less than ten aircraft
(1) Aviation U n i t Maintenance (AVUM).
assigned. Maintenance tasks performed by the air-
AVUM activities will be staffed and equipped to
craft crew chief or assigned aircraft repairman will
normally be limited to preventive maintenance in-
maintenance tasks required to retain or return
spections, servicing, spot painting, spot drilling,
equipment t o a serviceable condition. The
minor adjustments, module/component fault
maintenance capability of the AVUM will be
diagnosis and replacement of selected
governed by the MAC and limited by the amount
modules/components. Repair functions will nor-
and complexity of support equipment, facilities re-
mally be accomplished by the supporting AVIM
quired, and number of spaces and critical skills
unit.
available. The range and quantity of authorized
(2) Aviation I n t e r m e d i a t e Maintenance
spare modules/components will be consistent with
(AVIM). AVIM provides mobile, responsive "One
the mobility requirements dictated by the air
s t o p " maintenance support. (Maintenance func-
mobility concept. (Assignment of maintenance
tions which are not conducive to sustaining air
tasks to divisional company size aviation units
mobility will be assigned to depot maintenance.)
will consider the overall maintenance capability of
Performs all maintenance functions authorized to
the division, the requirement to conserve person-
be done at AVUM. Repair of equipment for return
nel and equipment resources and air mobility re-
to user will emphasize support or operational
quirements).
readiness requirements. Authorized maintenance
(a) Company Size Aviation Units. Perform
includes replacement and repair of modules/com-
those tasks which consist primarily of preventive
ponents and end items which can be accomplished
maintenance and maintenance repair and replace-
efficiently with available skills, tools, and equip-
ment functions associated with sustaining a high
ment. Establishes the Direct Exchange (DX) pro-
level of equipment operational readiness. Perform
gram for AVUM units by repairing selected items
maintenance inspections and servicing to include
for return to stock when such repairs cannot be ac-
daily, intermediate, periodic and special inspec-
complished a t t h e A V U M l e v e l . I n s p e c t s ,
tions as authorized by the MAC or higher head-
troubleshoots, tests, diagnoses, repairs, adjusts,
quarters. Identify the cause of equipment/system
B-1