AVIATION SHOP EQUIPMENT CONTACT MAINTENANCE (AV SECM) SYSTEM MAINTENANCE ALLOCATION
CHART (MAC) INTRODUCTION - (CONTINUED)
The following deinitions are applicable to the "repair" maintenance function:
Services. Inspect, test, service, adjust, align, calibrate, and/or replace.
Fault location/troubleshooting. The process of investigating and detecting the cause of
equipment malfunctioning; the act of isolating a fault within a system or Unit Under Test (UUT).
Disassembly/assembly. The step-by-step taking apart (or breakdown) of a spare/functional
group coded item to the level of its least component identiied as maintenance signiicant (i.e.,
assigned an SMR code) for the level of maintenance under consideration.
Actions. Welding, grinding, riveting, straightening, facing, machining, and/or resurfacing.
11. Overhaul. That maintenance effort (service/action) prescribed to restore an item to a completely
serviceable/operational condition as required by maintenance standards in appropriate technical
publications. Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul
does not normally return an item to like new condition.
12. Rebuild. Those services/actions necessary for the restoration of unserviceable equipment to a like new
condition in accordance with original manufacturing standards. Rebuild is the highest degree of materiel
maintenance applied to Army equipment. The rebuild operation includes the act of returning to zero those
age measurements (e.g., hours/miles) considered in classifying Army equipment/components.
Explanation Of Entries In The MAC
Columns (1) - Group Number and (2) Component/Assembly. The functional groupings in the sample below identify
maintenance signiicant components, assemblies, subassemblies, and modules with the next higher assembly.
ENGINE, GENERAL Servicing, handling inspection requirements, overhaul and retirement schedules.
External lines and hoses. (As applicable.)
COMPRESSOR SECTION (COLD SECTION MODULE) Rotor, blades, vanes, impeller, stators, inlet
guide vanes, mainframe, particle separator, bleed valve, bearings, seals, external lines and hoses.
POWER-TURBINE (POWER TURBINE MODULE) Nozzles, rotors, blades, exit guide vanes, exhaust
frame, drive shaft, bearings, seals, external lines and hoses.
ACCESSORY GEAR BOX (ACCESORY SECTION MODULE) Input and output gears, seals, chip
detector, housings, drive shaft, bearings.
FUEL SYSTEM Fuel control, fuel boost pump, governors, fuel ilter assembly, sequence valve, fuel
manifold, fuel nozzle, external lines and hoses.
ELECTRICAL SYSTEM Electrical control units, exciters, thermocouples, ignition harness, electrical
cables, history record, torque over speed sensor, Np sensor, external lines and hoses.
OIL SYSTEM Tanks, oil ilter, oil cooler, lube and scavenger pumps, oil ilter bypass sensor, external
lines and hoses.
Column (3) - Maintenance Function. Column (3) lists the functions to be performed on the items listed in
Column (5) - Tools and Equipment Reference Code. Column (5) speciies, by code, those common tool sets (not
individual tools), common TMDE, and special tools, special TMDE, and special support equipment required to
perform the designated function.
Column (6) - Remarks Code. When applicable, this column contains a letter code, in alphabetical order, which
is keyed to the remarks.