AO - (Assembled by
Items with these codes are not to be requested/requisitioned
individually. The parts that make up the assembled item must be
requisitioned or fabricated and assembled at the category of
AF - (Assembled by
maintenance indicated by the source code. If the 3d position code of
the SMR code authorizes you to replace the item, but the source
code indicates the item is assembled at a higher category, order the
AH - (Assembled by
item from the higher category of maintenance.
AD - (Assembled by
Do not requisition an "XA"-coded item.
Order its next higher assembly. (Also, refer to the NOTE below.)
If an "XB" item is not available from salvage, order it using the FSCM and part number given.
Installation drawing, diagram, instruction sheet, field service drawing, that is identified by manufacturer's part
Item is not stocked. Order an "XD"-coded item through normal supply channels using the FSCM and part
number given, if no NSN is available.
Cannibalization or controlled exchange, when authorized, may be used as a source of supply for items
with the above source codes, except for those source coded "XA" or those aircraft support items
restricted by requirements of AR 700-42.
(2) Maintenance Code. Maintenance codes tell you the category(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 follows:
(a) The maintenance code entered in the third position tells you the lowest maintenance category authorized to
remove, replace, and use an item. The maintenance code entered in the third position will indicate authorization to one
of the following categories of maintenance.
Crew or operator maintenance done within organizational or aviation unit maintenance.
Organizational or aviation unit category can remove, replace, and use the item.
Direct support or aviation intermediate category can remove, replace, and use the item.
General support category can remove, replace, and use the item.