EXPLANATION OF COLUMNS (Section II) Con't
Installation drawing, diagram, instruction sheet, field service drawing that is identified
by manufacturer's part number.
Stocked items; use the applicable NSN to request/requisition items with these codes.
They are authorized to the category indicated by the code in the 3rd position of the
MO - (Made at
Items with these codes are not to be requested/requisitioned individually. They must
be made from bulk material, which is identified by the NSN or part number in the
Bulk Material group of the repair parts list in this manual. If the item is authorized to
you by the 3rd position code of the SMR code, but the source code indicates it is made
MF - (Made at DS
at a higher level, order the item from the higher level of maintenance.
Items with these codes are not to be requested/requisitioned individually. The parts
AO - (Assembled
that make up the assembled item must be requisitioned or fabricated and assembled at
at Unit Level)
the level of maintenance indicated by the source code. If the 3rd position code of the
AF - (Assembled
SMR code authorizes you to replace the item, but the source code indicates the item is
at Direct Support)
assembled at a higher level, order the item from the higher level of maintenance.
Cannibalization when authorized may be used as a source of supply for
items with the above source codes.
(2) Maintenance Code. Maintenance codes tell you the level(s) of maintenance authorized to USE and REPAIR
support items. The maintenance codes are entered in the third and fourth positions of the SMR Code as
The maintenance code entered in the third position tells you the lowest maintenance level authorized
to remove, replace, and use an item. The maintenance code entered in the third position will indicate
authorization to one of the following levels of maintenance.
-Crew or operator maintenance done within organizational or aviation unit maintenance.
-Unit maintenance can remove, replace, and use the item.
-Direct support or aviation intermediate level can remove, replace, and use the item.
The maintenance code entered in the fourth position tells you whether or not the item is to be repaired
and identifies the lowest maintenance level with the capability to do complete repair (i.e., perform all
authorized repair functions).
Some limited repair may be done on the item at a lower level of maintenance, if
authorized by the Maintenance Allocation Chart (MAC) and SMR codes. This
position will contain one of the following maintenance codes.