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
level of 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 items are
assembled at a higher level, order the item from the higher level of maintenance.
XA--Do not requisition an "XA"-coded item. Order its next higher assembly. (Also, refer to the NOTE below.)
XB--If an "XB" item is not available from salvage, order it using the FSCM and part number given.
XC--Installation drawing, diagram, instruction sheet, field service drawing, that is identified by manufacturer's part
XD--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 tells 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 follows:
(a) 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.
--Organizational or aviation unit category can remove, replace, and use the item.
--Direct support or aviation intermediate level can remove, replace, and use the item.